1. No category

PRODUCT SAFETY BULLETIN
Styrene Monomer
Foreword
Lyondell Chemical Company is dedicated to continuous
improvement in product, health, safety and environmental
performance. Included in this effort is a commitment to support our
customers by providing guidance and information on the safe use of
our products. For Lyondell Chemical Company, environmentally
sound operations, like environmentally sound products, make good
business sense. Lyondell Chemical Company Product Safety Bulletins
are prepared by our Product Stewardship Team. The data reflects
the best information available from public and industry sources. This
document is provided to support the safe handling, use, storage,
transportation and ultimate disposal of our chemical products.
This Product Safety Bulletin should be evaluated to determine
applicability to your specific requirements. Please make sure you
review the government regulations, industry standards and guidelines
cited in this bulletin that might have an impact on your operations.
Lyondell Chemical Company is ready to support our customers’ safe
use of our products. For additional information and assistance, please
contact your Lyondell Chemical Company customer representative.
December 2007
Lyondell Chemical Company, headquartered in Houston, Texas, is North America's third-largest independent, publicly traded
chemical company. Lyondell is a leading global manufacturer of chemicals and plastics, a refiner of heavy, high-sulfur crude oil
and a significant producer of fuel products. Key products include ethylene, polyethylene, styrene monomer, propylene, propylene
oxide, gasoline, ultra low-sulfur diesel, MTBE and ETBE.
Product Safety Bulletin i
IN CASE OF A TRANSPORTATION EMERGENCY, CALL:
CHEMTREC (800) 424-9300
International (call collect) (202) 483-7616
or
CANUTEC (in Canada)
(613) 996-6666
or
SETIQ (in the Mexican Republic)
(800) 002-1400
(Calls originating in Mexico City or the Metropolitan Area) (5) 559-1588
(Calls originating elsewhere) (52-555) 559-1588
or
Lyondell SCDI (Serious Chemical Distribution Incident) Reporting Hotline
(800) 245-4532
FOR MORE INFORMATION ABOUT OUR PRODUCT, CALL:
Lyondell Chemical Company Customer Service
(888) 777-0232 (USA)
(33-3) 4424-9205 (Europe, Middle East, Asia)
(55-11) 5185-9300 (South America)
or visit
www.lyondell.com
We are pleased to provide you with the most recently revised Styrene Monomer Product Safety Bulletin. Please
discard any previous versions of this document. This bulletin is provided as a service without charge to our
customers and contractors and should be utilized at their own discretion and risk. It is intended for persons with
specialized knowledge and technical skills, which are required for proper understanding and interpretation of the
information contained herein. The information was obtained from sources believed to be reliable and is based on
industry practices prevailing at the time of compilation, which are subject to change and may be subject to
variance. The information in this bulletin is provided without any warranty, expressed or implied, regarding its
accuracy and completeness. Recipients are expected and advised to undertake their own inquiry and study and be
trained in the environmental, health and safety requirements of the product. Customers and contractors should also
be familiar with applicable federal, state and local laws and regulations. References to a specific product line or any
list of suppliers are provided as a matter of convenience, and are not an endorsement or recommendation of a
particular brand or company. In addition, the information is to be used only for this product. If the product is used
as a component in, or in combination with, another product, the information may not be accurate or applicable.
For the above reasons, and because the conditions and methods of handling, storage, use and disposal of the
product are beyond our control and may be beyond our knowledge, we do not assume any responsibility and
expressly disclaim any liability for loss, damage or expense arising out of or in connection with the use of the
information set forth herein, and the handling, storage, use or disposal of the product. This document contains
dated material. Recipients are advised to evaluate the timeliness of information cited. The latest revision of this
Product Safety Bulletin can be obtained from our web site at www.lyondell.com.
ii Product Safety Bulletin
TABLE OF CONTENTS
1. GENERAL INFORMATION . . . . . . . . . . . . . . . . 1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
Product Identification
Physical Properties
Typical Values
Instability Hazards
Reactivity Hazards
Self-Polymerization
Precautions When Handling TBC
2. OCCUPATIONAL HEALTH . . . . . . . . . . . . . . . 13
2.1
2.2
2.3
2.4
Hazard Assessment
Occupational Exposure Limits
First Aid
Medical Management
3. PERSONAL SAFETY AND HEALTH . . . . . . . 19
3.1
3.2
3.3
3.4
3.5
Site Facilities
Hygiene Practices
Personal Protective Equipment (PPE)
Respiratory Protection
Direct Reading Instruments
Air Sampling and Analysis
4. ENGINEERING . . . . . . . . . . . . . . . . . . . . . . . . 21
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
Bulk Storage
Piping
Electrical Area Classification
Pump Specifications
Instrumentation
Relief Requirements
Leak Detection Devices
Material Requirements
Vapor Containment System
Chemical Compatibility
5. FIRE SAFETY . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.1
5.2
5.3
5.4
Fire and Explosion Hazard
Fire Prevention
Fire Suppression
Fire Fighting
6. HAZARD COMMUNICATION . . . . . . . . . . . . . 25
6.1
6.2
6.3
7. ENVIRONMENTAL . . . . . . . . . . . . . . . . . . . . . 29
7.1
7.2
7.3
Air Quality Considerations
Clean Water Act
Waste Management
8. PRODUCT STORAGE . . . . . . . . . . . . . . . . . . . 33
8.1
8.2
8.3
8.4
Drum Storage
Storage Tanks
Unloading Installations Workplace Location
9. TRANSFER OPERATIONS . . . . . . . . . . . . . . . 39
9.1
9.2
9.3
9.4
9.5
9.6
Work Preparation
Tank Cars DOT 111A
Tank Cars DOT 105J
Tank Trucks
ISO Tanks
Marine Transport
10. TANK CLEANING AND
EQUIPMENT REPAIR . . . . . . . . . . . . . . . . . . 51
10.1
10.2
10.3
10.4
10.5
Work Preparation
Control of Hazardous Energy
Confined Space Entry
Equipment Cleanout
Maintenance and Inspection
11. Transportation Regulatory
Requirements . . . . . . . . . . . . . . . . . . . . . . 53
11.1
11.2
11.3
11.4
Classification
Marking, Labeling and Placarding
Packaging
Transportation Emergencies
APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
A1.
A2.
A3.
A4.
A5.
A6.
A7.
Conversion Factors
Worldwide Occupational Exposure Limits
Names and Addresses of Manufacturers
References
Regulatory Summary
Visual Quick Test
Glossary
OSHA Hazard Communication
SARA Title III
State Regulations
Product Safety Bulletin iii
1. GENERAL INFORMATION
1.1 Product Identification
1.1.2 Applications
Chemical Name Chemical Family Common Names CAS# Formula Styrene monomer is a basic building block of the plastic
industry. It is used to make a host of downstream derivative
products that go into millions of consumer goods. Primary
derivatives of styrene monomer, in order of demand, include:
polystyrene, expandable polystyrene (EPS) and acrylonitrilebutadiene-styrene (ABS)/styrene-acrylonitrile (SAN) resins,
styrene butadiene (SB) latex, SB Rubber (SBR), unsaturated
polyester resins (UPR), specialty polymers, co-polymers
and styrene thermoplastic elastomers (TPE) (see Figures 1.3
and 1.4).
Polystyrene is one of the easiest plastics to use to produce
commodity packages and consumer goods. It is primarily used
in insulation, packaging, appliances, furniture, toys and
cassettes. It consumed 49 percent of the world production of
styrene monomer based on 2004 data.
Expandable polystyrene (EPS) beads are produced from
styrene monomer and non-CFC (chlorinated fluorocarbons)
blowing agents. It is primarily used in food packaging,
insulation and cushion packaging. Resins of ABS/SAN are used
in construction materials, appliances, business machines and
transportation. Expandable polystyrene and ABS/SAN resins
accounted for 30 percent of the world production based on
2004 data.
Other applications include paper and textile coatings and
carpet backing (SB latex), production of tires (SBR),
construction and marine applications (UPR), adhesives and
polymer modification (TPEs), etc.
Polystyrene products are recyclable. In the past, polystyrene
companies routinely recycled plant scraps to make their
manufacturing processes as efficient as possible. More recently,
with growing concerns about how it disposes of its wastes, the
polystyrene industry has started recycling post consumer
polystyrene packaging. Polystyrene is being recycled back into
packaging, as well as durable goods such as office supplies, house
and garden products, construction materials, video cassettes and
other useful products.
Ethenylbenzene
Aromatic Hydrocarbon
Styrene monomer
Vinylbenzene
Vinylbenzol
Phenylethylene
Phenethylene
Phenylethene
Cinnamol
Cinnamene
Styrol
Styrole
Styrolene
100-42-5
C8H8
1.1.1 Chemistry
The conventional method of producing styrene monomer
involves the alkylation of benzene with ethylene to produce
ethylbenzene, which is followed by dehydrogenation to produce
styrene monomer. This process accounts for over 80 percent
(CMAI, 2004) of the world’s total styrene monomer production
(see Figure 1.1).
Lyondell Chemical Company uses an alternative process, a
proprietary technology, to manufacture styrene monomer.
Ethylbenzene is oxidized to form ethylbenzene hydroperoxide,
which reacts with propylene to form propylene oxide and
methyl benzyl alcohol. Methyl benzyl alcohol is then dehydrated
to form styrene monomer (see Figure 1.2).
Product Safety Bulletin 1
General Information
Figure 1.1 Conventional Technology
CH2 – CH3
C2H4
ALKYLATION
+
Ethylene
Ethylbenzene
Benzene
CH2 – CH3
CH = CH2
DEHYDROGENATION
+
Styrene Monomer
Ethylbenzene
H2
Hydrogen
Figure 1.2 Lyondell Chemical Company Technology
O – OH
CH2 – CH3
OXIDATION
CH – CH3
+
O2
Ethylbenzene
Ethylbenzene
Hydroperoxide
O – OH
EPOXIDATION
CH – CH3
+ CH3 – CH = CH2
Ethylbenzene
Hydroperoxide
OH
DEHYDRATION
OH
CH – CH3
Methyl Benzyl
Alcohol
2 Product Safety Bulletin
Propylene
CH2 – CH – CH3 +
O
Propylene Oxide
CH = CH2
+
Styrene Monomer
H 2O
CH – CH3
Methyl Benzyl
Alcohol
General Information
MAJOR USES FOR STYRENE MONOMER
Figure 1.3 Major Uses of Syrene Monomer
STYRENE MONOMER
EXPANDABLE POLYSTYRENE
(EPS)
POLYSTYRENE (PS)
Food Packaging
Insulation
Cushion Packaging
Commodity Packages
Consumer Goods
Insulation
Appliances
Furniture
Toys
Cassettes
STYRENE BUTADIENE RUBBER
(SBR)
STYRENE BUTADIENE LATEX
(SB LATEX)
Tires
Paper and Textile Coatings
Carpet Backing
ACRYLONITRILE-BUTADIENE-STYRENE (ABS)
STYRENE-ACRYLONITRILE (SAN) RESINS
Construction Materials
Appliances
Business Machines
Transportation Material
UNSATURATED POLYESTER
RESINS (UPR RESINS)
Construction
Marine Applications
ADDITIONAL STYRENE DERIVATIVES
Figure 1.4 Additional Styrene Monomer Derivatives
STYRENE MONOMER
STYRENE BUTADIENE
C0-POLYMER (K-RESIN)
METHYL METHACRYLATE BUTADIENE,
STYRENE CO-POLYMER (MBS)
STYRENE AND MALEIC ANHYDRIDE
CO-POLYMER (SMA)
Stronger Packaging Products
Impact Modifier for PVC Resins
Automotive Interior Parts
THERMOPLASTIC ELASTOMERS
(TPE)
Adhesives
Polymer Modification
OTHER
DERIVATIVES
Coatings
Esters
Polymer Polyols
Polystyrene Latex
Terpine Resins
XT Polymer by CYRP
Product Safety Bulletin 3
General Information
1.2 Physical Properties
Table 1.1. Styrene Monomer Physical Properties
PROPERTY
VALUE
PROPERTY
VALUE
Physical State
Liquid
24.84 Kcal/mol
Color
Colorless
Heat/Formation,
Liquid @ 25°C
Boiling Pt.
145.2°C (293.4°F)
Heat/Fusion
@ -30.6°C
2617 cal/mol
4711 BTU/lbmol
Molecular Wt.
104.152
Heat/Vaporization
See Figure 1.9
Freezing Pt.
-30.6°C (-23.1°F)
Density @ 25°C
0.9011 g/ml
Heat Capacity of
Sat’d Liquid
See Figure 1.10
Density of Sat’d Liquid
See Figure 1.5 and Table
1.2
Enthalpy of Sat’d Liquid
See Figure 1.11
Heat Capacity of Vapor
See Figure 1.12
Vapor Density
See Figure 1.6
Enthalpy of Sat’d Vapor
See Figure 1.13
Vapor Pressure
See Table 1.3
Surface Tension
See Figure 1.14
Viscosity of Sat’d Liquid
See Figure 1.7
Viscosity of Vapor
See Figure 1.8
Thermal Conductivity
of Sat’d Liquid
See Figure 1.15
Index/Refraction
@ 20°C
@ 25°C
1.54682
1.54395
Thermal Conductivity of
Vapor
See Figure 1.16
Flash Point (TCC)
31.9°C (90°F)
Auto Ignition
490°C (914°F)
Upper Flam. Limit
6.1 vol%
Coeff. of Cubical
Expansion @ 20°C
0.000971°C –1
Crit. Temperature
363°C (685°F)
Lower Flam. Limit
1.1 vol%
Crit. Pressure
3.84 MPa
557.0 psia
Solubility @ 20°C
Crit. Volume
3.38 cc/g
0.0541 ft3/lb
Water: 0.032 wt%
Alcohol: ∞
Ether: ∞
Sat. Conc. in Air @ 25°C
Crit. Compress.
0.256
0.81 mol%
2.84 wt%
Acentric Factor
0.2971
Dipole Moment
4.33 x 10-31 C•m
Heat/Combustion,
Liquid @ 25°C
-1019 Kcal/mol
Heat/Polymerization
@25°C
16.68 Kcal/mol
Heat/Formation,
Vapor @ 25°C
35.23 Kcal/mol
Minimum Oxygen for
Combustion (MOC)
9.0%
4 Product Safety Bulletin
General Information
Figure 1.5 Styrene Monomer Density of Saturated Liquid as a Function of Temperature
0.95
0.94
0.93
Density of Saturated Liquid (g/cc)
0.92
0.91
0.90
0.89
0.88
0.87
0.86
0.85
0.84
0.83
0.82
0.81
0.80
0.79
0.78
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Temperature (°C)
Table 1.2 Styrene Monomer Density as a Function of Temperature
Temperature
°C
°F
4.4
5.0
5.6
6.1
6.7
7.2
7.8
8.3
8.9
9.4
10.0
10.6
11.1
11.7
12.2
12.8
13.3
13.9
14.4
15.0
15.6
16.1
16.7
17.2
17.8
18.3
18.9
19.4
20.0
20.6
21.1
21.7
22.2
22.8
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
Lbs. Per U.S.
Gallon
7.665
7.661
7.657
7.653
7.649
7.645
7.641
7.637
7.633
7.629
7.624
7.620
7.616
7.612
7.608
7.604
7.600
7.596
7.592
7.588
7.584
7.580
7.575
7.571
7.567
7.563
7.559
7.555
7.551
7.547
7.543
7.538
7.534
7.530
Sp. Gr. to
60°F
1.0107
1.0102
1.0097
1.0091
1.0086
1.0081
1.0075
1.0070
1.0065
1.0059
1.0054
1.0048
1.0043
1.0038
1.0032
1.0027
1.0022
1.0016
1.0011
1.0005
1.0000
0.9995
0.9989
0.9984
0.9978
0.9973
0.9968
0.9962
0.9957
0.9951
0.9946
0.9940
0.9935
0.9930
Temperature
°C
°F
23.3
23.9
24.4
25.0
25.6
26.1
26.7
27.2
27.8
28.3
28.9
29.4
30.0
30.6
31.1
31.7
32.2
32.8
33.3
33.9
34.4
35.0
35.6
36.1
36.7
37.2
37.8
38.3
38.9
39.4
40.0
40.6
41.1
41.7
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
Lbs. Per U.S.
Gallon
7.526
7.522
7.518
7.514
7.510
7.505
7.501
7.497
7.493
7.489
7.485
7.481
7.476
7.472
7.468
7.464
7.460
7.456
7.451
7.447
7.443
7.439
7.435
7.430
7.426
7.422
7.418
7.414
7.409
7.405
7.401
7.397
7.393
7.388
Sp. Gr. to
60°F
0.9924
0.9919
0.9913
0.9908
0.9902
0.9897
0.9891
0.9886
0.9880
0.9875
0.9869
0.9864
0.9859
0.9853
0.9848
0.9842
0.9837
0.9831
0.9826
0.9820
0.9815
0.9809
0.9804
0.9798
0.9792
0.9787
0.9781
0.9776
0.9770
0.9765
0.9759
0.9754
0.9748
0.9743
Temperature
°C
°F
42.2
42.8
43.3
43.9
44.4
45.0
45.6
46.1
46.7
47.2
47.8
48.3
48.9
49.4
50.0
50.6
51.1
51.7
52.2
52.8
53.3
53.9
54.4
55.0
55.6
56.1
56.7
57.2
57.8
58.3
58.9
59.4
60.0
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
Lbs. Per U.S.
Gallon
7.384
7.380
7.376
7.372
7.367
7.363
7.359
7.355
7.350
7.346
7.342
7.338
7.333
7.329
7.325
7.321
7.316
7.312
7.308
7.304
7.299
7.295
7.291
7.287
7.282
7.278
7.274
7.269
7.265
7.261
7.256
7.252
7.248
Sp. Gr. to
60°F
0.9737
0.9731
0.9726
0.9720
0.9715
0.9709
0.9704
0.9698
0.9692
0.9687
0.9681
0.9676
0.9670
0.9664
0.9659
0.9653
0.9648
0.9642
0.9636
0.9631
0.9625
0.9619
0.9614
0.9608
0.9603
0.9597
0.9591
0.9586
0.9580
0.9574
0.9569
0.9563
0.9557
Product Safety Bulletin 5
General Information
Figure 1.6 Styrene Monomer Density of Vapor @ 1 Atmosphere as a Function of Temperature
4.7
4.6
4.5
4.4
Density of Vapor x 103 (g/cc)
4.3
4.2
4.1
4.0
3.9
3.8
3.7
3.6
3.5
3.4
3.3
3.2
3.1
3.0
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Temperature (°C)
Table 1.3. Styrene Monomer Vapor Pressure as a Function of Temperature
Temperature
°C
°F
mm Hg
Vapor Pressure
psia
psig
Temperature
°C
°F
mm Hg
Vapor Pressure
psia
-30.00
-22.00
0.08
0.00
90.00
194.00
134.58
2.60
-25.00
-13.00
0.14
0.00
95.00
203.00
161.55
3.12
-20.00
-4.00
0.22
0.00
100.00
212.00
192.76
3.73
-15.00
5.00
0.34
0.01
105.00
221.00
228.67
4.42
-10.00
14.00
0.52
0.01
110.00
230.00
269.80
5.22
-5.00
23.00
0.77
0.01
115.00
239.00
316.65
6.12
0.00
32.00
1.13
0.02
120.00
248.00
369.80
7.15
5.00
41.00
1.64
0.03
125.00
257.00
429.81
8.31
10.00
50.00
2.33
0.04
130.00
266.00
497.30
9.62
15.00
59.00
3.26
0.06
135.00
275.00
572.90
11.08
psig
20.00
68.00
4.50
0.09
140.00
284.00
657.25
12.71
25.00
77.00
6.12
0.12
145.00
293.00
751.05
14.52
30.00
86.00
8.24
0.16
145.45
293.81
760.00
14.70
0.00
35.00
95.00
10.96
0.21
150.00
302.00
854.98
16.53
1.84
40.00
104.00
14.40
0.28
155.00
311.00
969.78
18.75
4.06
45.00
113.00
18.74
0.36
160.00
320.00
1096.19
21.20
6.50
50.00
122.00
24.13
0.47
165.00
329.00
1234.98
23.88
9.18
55.00
131.00
30.78
0.60
170.00
338.00
1386.95
26.82
12.12
60.00
140.00
38.91
0.75
175.00
347.00
1552.89
30.03
15.33
65.00
149.00
48.78
0.94
180.00
356.00
1733.66
33.52
18.83
70.00
158.00
60.64
1.17
185.00
365.00
1930.10
37.32
22.63
75.00
167.00
74.81
1.45
190.00
374.00
2143.09
41.44
26.74
80.00
176.00
91.61
1.77
195.00
383.00
2373.53
45.90
31.20
85.00
185.00
111.41
2.15
200.00
392.00
2622.35
50.71
36.01
6 Product Safety Bulletin
General Information
Figure 1.7 Styrene Monomer Viscosity of Saturated Liquid as a Function of Temperature
1.9
1.8
1.7
Viscosity of Saturated Liquid (cps)
1.6
1.5
1.4
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2 -30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Temperature (°C)
Figure 1.8 Styrene Monomer Viscosity of Vapor @ 1 Atmosphere as a Function of Temperature
9.0
8.8
8.6
8.4
8.2
Viscosity of Vapor x 103 (cps)
8.0
7.8
7.6
7.4
7.2
7.0
6.8
6.6
6.4
6.2
6.0
5.8
5.6
5.4
5.2
5.0
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Temperature (°C)
Product Safety Bulletin 7
General Information
Figure 1.9 Styrene Monomer Heat of Vaporization as a Function of Temperature
110
108
106
Heat of Vaporization (cal/g)
104
102
100
98
96
94
92
90
88
86
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Temperature (°C)
Figure 1.10 Styrene Monomer Heat Capacity of Saturated Liquid as a Function of Temperature
0.52
Heat Capacity of Saturated Liquid (cal/g°C)
0.51
0.50
0.49
0.48
0.47
0.46
0.45
0.44
0.43
0.42
0.41
0.40
0.39
0.38
-30
-20
-10
0
10
20
30
40
50
60
Temperature (°C)
8 Product Safety Bulletin
70
80
90
100
110
120
130
140
General Information
Figure 1.11 Styrene Monomer Enthalpy of Saturated Liquid as a Function of Temperature
70
65
60
Enthalpy of Saturated Liquid (cal/g)
55
50
45
40
35
30
25
20
15
10
5
0
-5
-10
-15
-20
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Temperature (°C)
Reference: Saturated Liquid Styrene Monomer at 0°C
Figure 1.12 Styrene Monomer Heat Capacity of Vapor (Ideal Gas) as a Function of Temperature
0.38
0.37
0.36
Heat Capacity of Vapor (cal/g°C)
0.35
0.34
0.33
0.32
0.31
0.30
0.29
0.28
0.27
0.26
0.25
0.24
0.23
-30
-20
-10
0
10
20
30
40
50
60
Temperature (°C)
70
80
90
100
110
120
130
140
Product Safety Bulletin 9
General Information
Figure 1.13 Styrene Monomer Enthalpy of Saturated Vapor as a Function of Temperature
150
Enthalpy of Saturated Vapor (cal/g)
145
140
135
130
125
120
115
110
105
100
95
-30
-20
-10
0
10
20
30
Reference: Saturated Liquid Styrene Monomer at 0°C
40
50
60
Temperature (°C)
70
80
90
100
110
120
130
140
Figure 1.14 Styrene Monomer Surface Tension as a Function of Temperature
32.5
32.0
31.5
31.0
Surface Tension (dynes/cm)
30.5
30.0
29.5
29.0
28.5
28.0
27.5
27.0
26.5
26.0
25.5
25.0
0
10
20
30
40
50
60
70
80
Temperature (°C)
10 Product Safety Bulletin
90
100
110
120
130
140
General Information
Figure 1.15 Styrene Monomer Thermal Conductivity of Saturated Liquid as a Function of Temperature
Thermal Conductivity of Saturated Liquid [Cal / (hr • cm • °C)]
1.30
1.28
1.26
1.24
1.22
1.20
1.18
1.16
1.14
1.12
1.10
1.08
1.06
1.04
1.02
1.00
0.98
0.96
0.94
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Temperature (°C)
Thermal Conductivity of Saturated Liquid [Cal / (hr • cm • °C)]
Figure 1.16 Styrene Monomer Thermal Conductivity of Vapor @ 1 Atmosphere as a Function
of Temperature
0.200
0.195
0.190
0.185
0.180
0.175
0.170
0.165
0.160
0.155
0.150
150
155
160
165
170
175
180
185
190
195
200
Temperature (°C)
Product Safety Bulletin 11
General Information
1.3 Typical Values
Lyondell styrene monomer meets the requirements of
ASTM D 2827-04:
Purity, wt% min . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.8
Ethylbenzene, ppm max . . . . . . . . . . . . . . . . . . . . . . . . . 500
Benzene, ppm max. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Aldehydes (as Benzaldehyde), ppm max . . . . . . . . . . . . 100
Peroxides (as H2O2), ppm max . . . . . . . . . . . . . . . . . . . . 50
Polymer, ppm max . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4-tert-Butylcatechol, ppm min . . . . . . . . . . . . . . . . . 10-15
Color, Pt-Co (ASTM D-1209), max . . . . . . . . . . . . . . . . 10
OR
Color, Pt-Co (ASTM D-5386), max . . . . . . . . . . . . . . . . 15
1.4 Instability Hazards
Styrene monomer can self-react and polymerize unless properly
inhibited. Polymerization will release heat and results in
temperature and pressure increases. The most commonly used
inhibitor is 4-tert-Butylcatechol (TBC). Maintaining the storage
temperature below 21°C (70°F) and the dissolved oxygen
content of the liquid at 15 to 20 ppm will help inhibit
polymerization (See Section 8.2.4).
1.5 Reactivity Hazards
Styrene monomer reacts with oxidizers, peroxides, strong
acids and alkali metal-graphite compounds. Avoid copper and
copper containing alloys. Styrene monomer will dissolve many
natural and synthetic rubbers. Storage vessels must be free of
rust and scale which can promote polymerization.
Styrene monomer emits acrid vapors on thermal
decomposition. Incomplete combustion can produce
carbon monoxide.
1.6 Self-Polymerization
Styrene monomer is inhibited with TBC to reduce and
control self-polymerization. Styrene monomer undergoes
polymerization slowly at ambient temperatures, but
polymerization will become rapid at elevated temperatures.
Styrene monomer may experience rapid polymerization if TBC
inhibitor and dissolved oxygen are depleted at elevated
temperatures or if product is contaminated with incompatible
materials. Styrene monomer polymerization is exothermic
evolving 290 BTU/lb (16.7 Kcal/mol). If excess heat is not
adequately dissipated, the product temperature will rise with a
subsequent rise in the rate of polymerization. At temperatures
above 65°C (149°F), runaway polymerization is possible.
When a runaway polymerization occurs, temperatures can
quickly exceed the boiling point of styrene monomer. Vapors
may erupt violently from tank vents or, if vents become plugged
with polymer, excessive pressure can be generated that may
rupture the containment vessel.
Styrene monomer should be monitored regularly for
TBC content. During excessive transit times, monitoring
12 Product Safety Bulletin
should also be conducted. At the first sign of uncontrolled
polymerization, TBC should be added and product temperature
should be reduced.
TBC inhibitor should be added as an 85 percent solution in
methanol. Add TBC to an initial concentration of 50-100 ppm
TBC in styrene monomer. Circulate tank contents to mix the
TBC in styrene monomer. If circulation is not possible, agitate
by bubbling air into tank bottom. (Caution: The air/styrene
monomer vapor mixture may be within the flammability
envelope). If runaway polymerization continues, add TBC up
to a 0.5 wt% concentration. Dilution with toluene, xylene or
ethylbenzene will slow the polymerization.
Lowering product temperature will also slow polymerization. Tanks can be cooled by refrigeration, circulation and
water spray.
When tank temperatures are stable and polymerization has
stopped, product should be removed from tank before it
becomes solid. If product’s viscosity prohibits removal, dilute
with toluene, xylene or ethylbenzene before emptying the tank.
1.7 Precautions When Handling TBC
TBC and solutions of TBC are corrosive and can cause severe
burns to the skin and eyes. TBC may cause allergic reactions in
certain individuals. Consult the manufacturer’s Material Safety
Data Sheet for additional information.
When handling TBC, personnel should prevent exposure
to the skin by wearing chemical protective gloves, apron and
boots. Prevent eye contact by wearing chemical splash goggles
or face shield.
2. OCCUPATIONAL HEALTH
2.1 Hazard Assessment
2.1.1 Acute Effects of Over Exposure
Styrene monomer is a highly volatile liquid with a low odor
threshold. The odor of styrene monomer has been described as
sweet and pleasant at low concentrations but disagreeable at
high concentrations. Styrene monomer has a low to moderate
order of acute toxicity. The major hazard from acute exposure to
styrene monomer is the irritant effect on the eyes, skin and
mucous membranes of the respiratory system. High inhalation
exposure may cause dizziness and central nervous system
depression, while ingestion may be fatal if aspiration into the
lungs occurs.
Styrene monomer may also increase the sensitivity of the
heart to endogenous neurotransmitters leading to potentially
fatal cardiac sensitization. Repeat inhalation studies demonstrate
that mouse nose and lung are highly sensitive to styrene
monomer vapor, while responses in the rat are much less
pronounced. Sensory and behavioral effects have also been
reported with repeated styrene monomer exposure. Mild, but
permanent, hearing loss was reported in rats after repeated
exposure to high concentrations of vapor. Minor impairment of
color discrimination and equivocal effects on behavior responses
have been identified in some studies of workers exposed to
styrene monomer. The available animal and human data
demonstrate that styrene monomer is not selectively toxic
toward the fetus, nor does it adversely impact reproduction.
Results from genotoxicity studies are generally negative with no
consistent or conclusive evidence of genetic damage in exposed
worker populations. Chronic inhalation to styrene monomer
vapor resulted in an increased incidence of pathology and late
onset tumors in the lungs of mice, which are believed to have
arisen through a nongenotoxic mechanism. Tumor incidence in
rats was unaffected after chronic inhalation exposure. The
available evidence from mechanistic studies and human
epidemiology studies indicate that humans are at low risk for
cancer from styrene monomer exposure.
Styrene monomer is of low to moderate toxicity following acute
(single dose) exposure. Single oral doses that produced lethality
(LD50) in laboratory animals ranged from 316 mg/kg in mice
to approximately 5000 mg/kg in rats. Inhalation exposure also
produced variable acute toxicity with mice that were apparently
more sensitive. Lethality was observed in mice administered
500 ppm styrene monomer vapor for six hours (LDLo),
whereas, a four-hour exposure to 2770 ppm styrene monomer
vapor was lethal (LD50) to rats. Acute toxicity associated with
dermal contact to styrene monomer has not been reported.
However, adverse systemic health effects are not expected
following accidental or incidental contact with styrene
monomer liquid. Styrene monomer liquid is moderately
irritating to the skin and eyes.
The predominant clinical signs and symptoms that may be
anticipated with over exposure to styrene monomer are irritation
to contact surfaces and central nervous system effects. Ingestion
of styrene monomer liquid may cause discomfort and irritation
of the gastrointestinal tract, and high vapor concentrations may
cause irritation of the eyes, nose and throat. High oral and
inhalation exposure to styrene monomer may cause central
nervous system depression as evidenced by fatigue, dizziness and
loss of concentration, with collapse, coma and death in cases of
severe exposure. Over exposure may also increase the sensitivity
of the heart to endogenous catecholamines leading to potentially
fatal cardiac sensitization. As with other hydrocarbons, styrene
monomer may be aspirated into the lungs and cause chemical
pneumonitis, which can be fatal.
A controlled exposure study of human volunteers to
styrene monomer vapor confirms that surface tissue contact
and the nervous system are targets of acute high-dose
exposure. Exposure of volunteers to 800 ppm styrene monomer
produced immediate symptoms of eye, nose and throat irritation
with drowsiness, listlessness and muscular weakness. At
approximately 200 ppm, nasal irritation was produced after
20 minutes of exposure. Exposure to 200 to 380 ppm styrene
monomer for 30 to 90 minutes reportedly produced altered
neurological effects (slightly impaired performance in
neurobehavioral tests). Upon removal from the styrene
monomer atmosphere, all of these symptoms readily reversed
with complete recovery. No symptoms of irritation or toxicity
were reported by volunteers exposed to 50 to 100 ppm styrene
monomer for one to two hours.
Product Safety Bulletin 13
Occupational Health
2.1.2 Repeated Exposures
Results from repeat-dose toxicity studies demonstrate that the
mouse is highly sensitive to styrene monomer-induced
respiratory toxicity, while toxicological responses in the rat are
less marked. Mechanistic studies demonstrate greater formation
of locally-toxic products in mouse nose and lung, and provide a
metabolic basis for these species differences in susceptibility.
Negligible metabolism in humans suggests that humans are less
susceptible than the mouse to styrene monomer-induced
respiratory tract toxicity. Sensory and behavioral effects have also
been reported with repeated styrene monomer exposure..
Mice that were exposed for two years to styrene monomer
vapor at concentrations ranging from 20 to 160 ppm exhibited
an increased incidence of hyperplasia and fibrosis in lung tissue
and atrophy and degeneration of nasal olfactory epithelium. In a
shorter-term (13 week) study, higher exposure concentrations
(150 to 200 ppm) produced abnormal liver histopathology in
mice; however, these effects were not apparent in the two-year
exposure study. In a companion rat two-year exposure study,
styrene monomer vapor concentrations ranging from 50 to
1000 ppm produced only mild nasal tissue changes with no
other treatment-related tissue effects noted. The olfactory
portion of the nasal mucosa in rats and mice has been
consistently reported to exhibit changes after inhalation of
styrene monomer vapor, with the most pronounced changes
seen in the mouse. Nasal lesions, however, have not been
reported for any species following exposure via other routes.
Uptake of styrene monomer in the respiratory tract is dependent
partly on the concentration of styrene monomer in air and
partly on the rate and extent of styrene monomer metabolism in
respiratory tissue. Metabolic investigations support differences
in rodent respiratory metabolism of styrene monomer which is
thought to account for the differential sensitivity of rat and mice
to styrene monomer- induced nasal and pulmonary toxicity.
Human metabolism of styrene monomer in nasal and
pulmonary tissue is expected to be very low, suggesting that
styrene monomer is unlikely to be toxic to human nasal
epithelium or lungs.
Effects on hearing, color vision and behavior have been
reported for styrene monomer. Exposure of rats to 600 ppm
styrene monomer vapor produced a mild (1-3 dB) increase in
auditory brainstem response and loss of outer hair cells in
regions of the organ of Corti. Combined exposure to noise and
styrene monomer gave a greater increase in auditory brainstem
response that was produced by either noise or styrene monomer
alone. There is some evidence of a minor effect on hearing in
human worker populations exposed to styrene monomer.
However, these studies had confounding factors (such as age and
co-exposure to noise) which preclude a definitive determination.
Decreased color discrimination (dyschromoatopsia) has been
reported in some workers following occupational exposure to
styrene monomer. Color vision measurements (Desat D-15 test)
found poorer color discrimination in workers exposed to styrene
monomer vapors in the range of approximately 30 to 50 ppm.
These changes, although statistically significant, were small in
14 Product Safety Bulletin
magnitude and hence unlikely to be of clinical significance.
Variable and inconsistent results have been reported in
laboratory animal and human neurobehavioral studies. In
studies conducted in rats, high vapor concentrations (500 ppm
and greater) produced transient reversible decreases in visual
response time and operant behavior but no effects on grip
strength, spontaneous activity and peripheral nerve conduction.
These findings may have been due to acute CNS depression
from the styrene monomer exposure. A number of human
workplace studies assessing potential long-term neurobehavioral
effects of repeated exposure to vapor have been reported. Some
of these investigations reported effects while others found no
change in workers exposed to similar or higher levels of styrene
monomer vapor. Overall, there is no consistency within or
between studies, and critical confounding factors were
unaddressed in the majority of the studies. Therefore, no
definite conclusion can presently be made on styrene monomer’s
potential for neurobehavioral decrements.
2.1.3 Reproductive and Developmental Toxicity
The potential for styrene monomer to induce toxicity to
reproduction and development has been studied in several
mammalian species. There is no convincing evidence that
styrene monomer will affect repro­duction or development at
doses which are not parentally toxic.
Results from reproductive toxicity studies in rats exposed
via drinking water or inhalation have shown that styrene
monomer is not selectively toxic to the gonads, nor does it
adversely affect fertility or litter parameters. A three-generation
study in rats conducted using dose levels of up to 250 ppm
(equivalent to daily doses for males of 14 mg/kg and females
of 21 mg/kg) found no effect on reproductive parameters. The
highest dose that could be tested in this study was limited by
the low solubility of styrene monomer in water. A recent
two-generation study has been conducted in rats exposed to
up to 500 ppm styrene monomer. The dams also received oral
equivalent doses (up to 300 mg/kg) between postnatal day
1 and 4 to assure continuous exposure to the pups (inhalation
exposure normally suspended during postnatal day 1 to 4, as
pup separation during this period is deleterious). Parental
mating and fertility indices (including sperm, ovary and estrus
parameters), mean live litter size and postnatal survival were
unaffected by styrene monomer treatment. Body weight, body
weight gain and feed consumption were decreased at various
times during the study in adult and pups of both sexes exposed
to 500 ppm, with less pronounced but significant reductions
also present in the 150 ppm groups. Overall, these results
provide no indication that styrene monomer adversely affected
reproductive performance in male and female rats exposed to
500 ppm over two generations. Results from 13-week and
two-year inhalation studies in rats and mice also found no
evidence of any adverse structural effect on ovaries, testes,
adrenals or uterus (mice only). Several studies have examined
reproductive function in male workers occupationally exposed
to styrene monomer. Overall, these studies provide no
Occupational Health
evidence of a link between internal body burden and
reproduction function.
Results from laboratory animal studies demonstrate that
styrene monomer is not a teratogen, nor is it fetotoxic at
sub-maternally toxic treatment levels. Styrene monomer has
been studied in a number of conventional developmental
toxicity studies conducted in rats, rabbits and hamsters using
inhalation or oral exposure. These studies did not find adverse
effects on embryo/fetal development at doses that did not
produce maternal toxicity. At high doses (300 ppm and greater),
there were some indications of fetal toxicity. However, these
occurred in the presence of maternal toxicity. A recent
developmental neurotoxicity study has been conducted in
rats as an adjunct to the two-generation reproductive toxicity
study. This study found some evidence of developmental
delay (prolonged acquisition of pinnal detachment and
balanopreputial separation), altered locomotor activity
(decreased, then increased) and neurobehavioral deficits
(increased escape time from a Biel maze, reduced forelimb/
hindlimb grip strength) in F2 litters exposed to 500 ppm
(300 mg/kg) styrene monomer. However, these findings were
attributed to decreased body weight, rather than a direct/
selective response of the offspring to styrene monomer exposure.
In an earlier study, decreases in brain neurotransmitter levels
were observed in pups from dams exposed to 300 ppm styrene
monomer but not at 50 or 60 ppm styrene monomer. The
significance of these brain chemical changes is unknown but
doubtful as they occurred at levels below which measurable
behavioral changes have been found in other studies.
A number of human epidemiological studies, focusing on
developmental effects, have been conducted but most of these
have too few subjects to be conclusive. There is limited evidence
from one study that styrene monomer may increase the rate of
spontaneous abortions in female workers. However, the majority
of studies have been generally negative and provide no reliable
evidence of styrene monomer exposure-related effects in relation
to spontaneous abortion, congenital abnormalities or birth
weight reductions.
2.1.4 Genetic Toxicity
The genotoxic potential of styrene monomer has been
investigated extensively. Results from in vitro tests are mostly
negative, although occasional positive findings have been
reported in some test systems, presumably reflecting conversion
of styrene monomer to styrene monomer oxide (a demonstrated
mutagen). In vivo studies in rats, mice and hamsters generally
show no increase in chromosomal aberrations or micronuclei
after single or repeated inhalation, oral or intraperitoneal
exposure. However, simultaneous assessment of sister chromatid
exchanges resulted in a weakly positive result in some of these
same studies. The significance of these findings to styrene
monomer mutagenicity is unclear.
A number of studies have been performed that examine the
genotoxic potential of styrene monomer in workers. The results
from these studies are generally negative, although a minority of
the studies indicates increased chromosomal aberrations or
micronuclei in peripheral lymphocytes following occupational
exposure. These findings, however, did not show an apparent
dose response relationship and were probably confounded by
previous or concurrent exposure of subjects to other genotoxic
substances, such that definitive conclusions cannot be drawn for
styrene monomer exposure. Overall, the available investigations
of genetic damage in exposed worker populations provide no
consistent or conclusive evidence for the genotoxicity of styrene
monomer in workers.
2.1.5 Carcinogenicity
The carcinogenic potential of styrene monomer has been
investigated in rats and mice after long-term inhalation or oral
exposure. Results for the rat provide no evidence of
carcinogenicity, whereas data from the mouse indicate an
increase in late-onset tumors in the lung (no other organ
affected). The mouse lung tumors occurred in the presence of
hyperplasia and inflammatory changes which were not present
in the rat lungs.
In rats, while individual studies have shown isolated
increases in various tumor types, these findings have typically
fallen within the historical background range for the tissue in
question, were not reproduced between studies, were not doserelated, or occurred at sites which have shown no other signs of
styrene monomer-related toxicity or morphological change. A
recent inhalation study that administered rats for two years to
up to 1000 ppm styrene monomer vapor found no increases in
tumor incidence. Overall, based on the results from eight
long-term carcinogenicity studies, there is no compelling
evidence that styrene monomer is carcinogenic in the rat.
In mice, the available data indicate that styrene monomer
produces an increase in lung tumors following lifetime exposure.
This is based on the findings from three oral gavage
administrations and a recent inhalation study, all of which
reported varying but increased incidences of pulmonary
adenoma and/or carcinoma. In the inhalation study, there were
no treatment-related neoplastic findings noted at the first
interim sacrifice at week 53. At the second interim sacrifice at
week 79, the occurrence of pulmonary bronchiolar-alveolar
adenoma was increased in some of the male and female
treatment groups. The observed increases in lung tumor
incidence occurred in conjunction with chronic inflammation.
At terminal sacrifice, a statistically significant dose-related
increase in pulmonary-bronchiolar adenomas was observed in
males at 40 ppm and above and in females at 20 ppm and
above. The incidence of bronchiolar-alveolar carcinomas was
significantly increased in females and increased, but not
significantly, in males. There were no significant differences
between styrene monomer-exposed and control animals for
tumors at other sites.
The tumor profile for styrene monomer is suggestive of a
nongenotoxic mode of action. Supporting information includes
the species- and tissue specificity of the late onset lung tumors in
mice and the presence of concurrent non-neoplastic
Product Safety Bulletin 15
Occupational Health
inflammatory changes in the tumor bearing tissue. Mechanistic
studies suggest that a styrene monomer metabolite(s) may be
responsible for the lung toxicity and tumor development, and
differences in species metabolism may explain differences in
species sensitivity to tumors. Metabolism studies have shown
that mouse lung is more efficient at metabolizing styrene
monomer, whereas pulmonary metabolism is negligible in rat
lung and virtually undetectable in human lung.
Several epidemiology studies of workers exposed to styrene
monomer during production of styrene/polystyrene, styrenebutadiene rubber and reinforced plastics and composites have
been reported. Of these studies, the studies in the reinforced
plastics and composites industry provide the most confident
assessment of cancer in light of higher exposure to styrene
monomer and less confounding from other chemical exposures.
In the reinforced plastics and composites industry studies, there
is no clear evidence that exposure to styrene monomer increased
the risk of cancer. In the other two manufacturing industries,
exposures to styrene monomer are much lower and are
confounded by a variety of other chemicals, a number of which
are suspected carcinogens. While several studies of workers in
these two industries have shown increases in certain types of
cancer, the data either strongly implicate other chemicals
present, or show no pattern consistent with a role of styrene
monomer. Overall, the combined weight of evidence from
studies from all industry segments supports a low concern
for cancer in humans from styrene monomer exposure.
The carcinogenicity of styrene monomer has been
reevaluated by IARC and the classification maintained as
possibly carcinogenic in humans – Group 2B. The IARC
working group concluded that there was limited evidence in
humans for the carcinogenicity of styrene monomer and also
limited evidence in animals.
2.2 Occupational Exposure Limits
The American Conference of Governmental Industrial
Hygienists (ACGIH) in the United States of America has
established a Threshold Limit Value (TLV) for styrene monomer
monomer. The TLV is 20 ppm as an 8-hour Time-Weighted
Average (TWA8) and 40 ppm as a 15-minute Short-Term
Exposure Limit (STEL). Some world-wide occupational
exposure limits are shown in Appendix 2.
The U.S. Department of Labor, Occupational Safety and
Health Administration (OSHA) has a Permissible Exposure
Limit (PEL) for styrene monomer which is less conservative
than the TLV. This value is listed in 29 CFR 1910.1000.
The U.S. National Institute for Occupational Safety and
Health (NIOSH) has classified 700 ppm of styrene monomer as
immediately dangerous to life and health (IDLH). This limit
represents the maximum concentration from which, in the event
of respirator failure, workers could escape within 30 minutes
from the contaminated workplace without experiencing any
escape impairing (for example, severe eye irritation) or
irreversible health effects.
16 Product Safety Bulletin
2.2.1 Warning Properties
Styrene monomer is a highly volatile liquid with a low odor
detection threshold of 0.14 ppm.
Styrene monomer has a sharp, sweet, pleasant odor at
low concentrations, but is disagreeable at high concentrations.
Styrene monomer is considered to have good warning properties.
2.3 First Aid
When an emergency arises, employees should approach the
accident site with caution. Do not become a casualty. Employees
should understand emergency procedures and know where
rescue equipment and emergency contact numbers are located
before the need arises.
Personnel providing assistance to a victim must be cautious
not to contaminate themselves by touching the victim’s clothing
unless wearing protective equipment such as gloves. The removal
of clothing from the victim, however, is important to minimize
continued skin contact and to prevent continued volatilization
of styrene monomer during transport to an emergency care
facility. Emergency transport services should be equipped to
provide continual flushing of the skin and eyes, especially when
the victim is complaining of a burning or irritating sensation.
2.3.1 Eye Contact
For eye contact, flush eyes immediately with copious amounts of
clean water for at least 15 minutes, periodically lifting the lower
and upper lids to enhance flushing. Individuals splashed with
styrene monomer may require assistance in locating emergency
eyewash stations and flushing the eyes. Medical attention should
be provided as soon as possible. An ophthalmologist should be
available for consultation.
2.3.2 Skin Contact
Anyone splashed by liquid styrene monomer should flush
affected areas thoroughly with water from a safety shower or
other running stream of water. While under the shower, the
exposed person should remove all contaminated clothing, rings,
watches, shoes or anything else that would prevent complete
flushing. All skin areas exposed to liquid styrene monomer
should then be washed with soap and water. If skin reddening is
noted, the exposed person should seek medical attention.
Clothing should not be reused before laundering.
2.3.3 Inhalation
If overcome from inhalation of styrene monomer, move victim
from contaminated atmosphere into fresh air at once. Treat for
shock if necessary. If victim has stopped breathing, administer
cardiopulmonary resuscitation (CPR) immediately. First aidtrained individuals, or equivalent, should administer CPR. The
victim should be monitored for respiratory distress. If cough or
difficulty in breathing develops, administer 100 percent
humidified supplementary oxygen with assisted ventilation, if
required. Seek prompt medical attention.
Occupational Health
2.3.4 Ingestion
Anyone who has swallowed styrene monomer should be given
a pint or more of warm water, but only if the exposed person
is completely conscious and alert. Vomiting should not be
induced; the risk of lung damage exceeds other hazards. If
vomiting occurs, have the person position their head below
waist level to minimize the risk of aspiration into the lungs.
Otherwise, chemical pneumonitis or bronchitis can result.
Seek prompt medical attention.
2.4 Medical Management
Employers are required by OSHA’s Medical Services and First
Aid Standard, 29 CFR 1910.151 to provide for medical
personnel in cases of medical emergency and/or employee
illness. In the absence of a clinic or hospital facility in close
proximity, the employer may have persons on site who are
adequately trained in appropriate first-aid techniques to handle
medical emergencies.
If no medical personnel are located at the facility, contact
should be made with an occupational health physician and
hospital emergency room to plan for medical emergencies.
Hospital selection should be based upon proximity and the
hospital’s ability to handle chemical emergencies. Copies of the
MSDS and the Product Safety Bulletin for styrene monomer
should be provided to, and reviewed with, medical personnel.
substances, special consideration should be given to those with
impaired renal function.
Since styrene monomer exposure may effect the respiratory
system, special consideration should be given to this when
pre-screening employees. A specific targeted protocol for the
initial medical examination developed by an occupational health
physician should be established before employing individuals
who may be exposed to styrene monomer.
2.4.2 Periodic Screening
Employees potentially exposed to styrene monomer should
receive routine medical evaluations. Periodic medical screening
is an effective tool for the identification and prevention of
occupational disease. In the United States, the ACGIH has
established a Biological Exposure Index (BEI) for styrene
monomer. Biological monitoring provides the occupational
physician with a method for assessing worker exposure.
Biological monitoring can be accomplished by determining
styrene monomer in blood or styrene monomer metabolites
in urine. Employers should consult with their occupational
health physicians to determine the specific targeted protocol to
be followed.
2.4.1 Initial Medical Screening
Prospective employees who may be potentially exposed to
styrene monomer should be physically able to work with styrene
monomer and, with reasonable accommodations, the personal
protective equipment which may be required.
An employee who will be working with or around styrene
monomer should have an initial medical screening for preexisting conditions that may be aggravated by styrene monomer
exposures. The individual may be stressed by wearing personal
protective equipment, which may include respiratory protection
and chemical protective clothing (see Sections 3.3 and 3.4).
Some employees are claustrophobic when placed in full-face
piece respiratory protection or full containment suits, or simply
when entering confined spaces.
Styrene monomer can cause skin irritation and blistering.
Persons with pre-existing skin disorders may be more susceptible
to the effects of this chemical. For persons with impaired
pulmonary function, especially those with obstructive airway
diseases, breathing styrene monomer may exacerbate symptoms.
Styrene monomer may affect the CNS, aggravating pre-existing
central nervous system disorders.
Although styrene monomer is not known as a liver toxin in
humans, the importance of the organ in the biotransformation
and detoxification of foreign substances should be considered
before exposing persons with impaired liver function. Similarly,
styrene monomer is not known as a kidney toxin. However, due
to the importance of this organ in the elimination of toxic
Product Safety Bulletin 17
3. PERSONAL SAFETY AND HEALTH
3.1 Site Facilities
If a potential for contact with styrene monomer exists in work
areas where it is handled or stored, quick drenching facilities and
equipment should be provided. This should include deluge
showers and eyewash stations. These items should be installed,
tested and maintained in accordance with the American
National Standards Institute, Inc. (ANSI) Z358.1 (see
Appendix 4 for citations). Workers should be familiar with
the location and operation of this safety equipment.
Workers should be provided with washing facilities for
cleaning before consuming food or beverages and before using
tobacco or cosmetics. Properly ventilated areas should be
provided where workers can take breaks and eat meals. Such
areas should be separate from those in which styrene monomer
or other chemicals are handled or stored.
Where the potential for exposure exists under normal
operating conditions, it would be prudent to have shower
facilities available for use at the end of the shift. There should be
provisions to separate work clothing from street clothing.
If contaminated clothing is laundered, appropriate facilities
should be provided. Styrene monomer will evaporate from
clothing potentially increasing the risk of worker exposure. Site
facilities should include closed containers for clothing storage
and engineering controls to limit worker exposure. Personnel
who will be handling contaminated clothing should be trained
and fully aware of the methods available to protect themselves,
including the use of personal protective equipment and methods
to determine vapor concentrations.
3.2 Hygiene Practices
Proper personal hygiene practices should be used while
working with and around styrene monomer. Employees should
be familiar with good work practices to avoid direct contact
with styrene monomer. Personal hygiene practices that should
be considered while working with and around styrene monomer
include prohibiting consumption and storage of food, use
and storage of tobacco products and application and storage
of cosmetics.
Styrene monomer should not be handled or stored in areas
where workers take breaks (such as lunch rooms) or in areas that
are not designed for styrene monomer storage. After handling
styrene monomer and prior to eating, smoking, drinking,
applying cosmetics or using toilet facilities, workers should
thoroughly wash their hands and faces with warm water and
mild soap/detergent.
Protective clothing and equipment used during the handling
of styrene monomer, including gloves, aprons, protective suits
and respirators, should be properly decontaminated using mild
soap/detergent and water. To prevent exposure, contaminated
clothing should be sealed in containers until laundered or
disposed of properly.
3.3 Personal Protective Equipment
(PPE) Respiratory Protection
Good industrial hygiene practice requires that engineering
controls be used to reduce employee workplace airborne
concentrations to below the ACGIH TLV of 20 ppm or other
local regulatory limits. However, if engineering controls are not
feasible, are being installed, or fail to control exposures and need
to be supplemented, respiratory protection should be provided
for workers. Respirators may also be needed for operations that
require confined-space entry into tanks or closed vessels and in
emergency situations resulting from spills/leaks and fire/
explosions involving styrene monomer. If respirators are
used, a complete respiratory protection program should be
implemented that includes training, inspection, medical
surveillance, fit testing, cleaning and maintenance.
Respiratory protection programs should meet the
requirements of OSHA Respiratory Protection Standard
(29 CFR 1910.134) and ANSI Z88.2.
When worker exposure exceeds established limits, NIOSHapproved respirators should be used. Table 3.1 provides
guidance for selecting respiratory protection.
3.3.1 Eye Protection
Chemical safety goggles should be worn whenever the
potential for exposure to vapor or liquid is present. A face
shield (8-inch minimum) may be worn to provide added
splash protection. These eye-protective measures should meet
ANSI Z87.1 specifications.
3.3.2 Foot Protection
Heavy overboots should be provided and worn over leather
shoes or boots to protect the leather from contamination.
Rubber boots should be worn under trouser legs to prevent
styrene monomer from entering the boot.
3.3.3 Skin Protection
Impervious protective clothing suitable for a particular task or
work activity should always be worn where chemical contact is
possible. Protective equipment can include an ensemble of
chemical–resistant gloves and a chemical apron to full-body
chemical-resistant coveralls, chemical gloves and a face-shield
for protection.
Product–specific styrene monomer permeation and
degradation data should be evaluated prior to specifying any
personal protective equipment (PPE). Protective clothing web
sites such as www.dupont.com are an excellent source of
information for making clothing selections based on the task.
Glove manufacturer’s web sites such as www.bestglove.com or
www.ansell.com provide chemical permeation and degradation
data on their specific gloves to many chemicals including
styrene monomer.
Product Safety Bulletin 19
Personal Safety and Health
Where the potential for exposure to styrene monomer
liquid exists, as in the case of a spill clean-up, or during
materials transfers/handling, employees should increase their
level of protection to liquid-tight coveralls as well as appropriate
face and hand protection. Liquid-tight PPE is designed to
protect employees from skin contact with styrene monomer
liquid. All PPE – including chemical-resistant suits, gloves,
boots, etc, – should be inspected prior to each use so as to
identify any damage, excessive wear or situations that may
compromise worker safety and health. If PPE is torn, damaged
or is contaminated with styrene monomer, then it should be
collected and properly disposed of in accordance with local,
state and federal regulations.
3.4 Direct Reading Instruments
Styrene monomer can be readily analyzed by a variety of directreading instruments. The advantage of using direct-reading
instruments is that real-time analysis and instantaneous air
concentrations can be determined. The value of a real-time
analysis, in terms of prevention of injury and illness, is
considerable. Direct-reading instruments that have been
successfully used to measure styrene monomer are combustible
gas indicators, infrared spectrophotometers, flame ionization
detectors, photoionization detectors and colorimetric detector
tubes. Appendix 3 contains a partial list of product vendors.
Limits of detection vary between these instruments and
should be evaluated to ensure proper use. The proper selection,
calibration, use and interpretation of direct-reading instruments
requires the services of an industrial hygienist or other
trained professional.
3.5 Air Sampling and Analysis
When assessing worker exposure to styrene monomer, an
extended sampling period is required. The accepted method of
air sampling is collection of the material on a sorbent media
over an extended period of time. Air is drawn at a measured rate
by a sampling pump into a charcoal tube. Passive samplers,
which use the diffusion characteristics of the material instead
of an active sampling pump, are also available. These methods
have been extensively developed and evaluated for use with
styrene monomer.
When considering the use of these methods for determining
employee exposure, it is important that a monitoring program
be developed by professional industrial hygienists. This
program should include sampling strategy, quality assurance
and statistical analysis of results.
Table 3.1 Styrene Monomer Respiratory Protection Selection Guide
Condition (Vapor Concentration)
Minimum Respiratory Protection* Required Above 20 ppm
20 ppm - 200 ppm
• A half-face negative pressure chemical cartridge respirator with organic
vapor cartridge.**
200 ppm - 500 ppm
• A full-face negative pressure chemical cartridge respirator with organic
vapor cartridge.**
500 ppm - 700 ppm
• Any half-face supplied air respirator (SAR) in continuous flow mode.
• Any full-face SAR in positive pressure or pressure demand mode.
• Requires an appropriately-sized escape bottle to be used in conjunction
with the SAR.
Greater than 700 ppm or unknown
concentration
• SCBA with full-face piece in pressure demand or positive pressure mode.
Fire Fighting
• SCBA with full-face piece in pressure demand or positive pressure mode.
Escape
• Any escape SCBA.
• Any full-face chemical cartridge respirator with organic vapor cartridges.
• Any full-face gas mask with an organic vapor canister/cartridge.
* Only approved/certified equipment should be used.
** If potential for eye irritation, recommend utilization of full-face respirator
20 Product Safety Bulletin
4. ENGINEERING
This section is included for use as a guideline. It is not
intended to be a design handbook and does not relieve the
user from exercising competent engineering judgment or
using qualified professional personnel to meet the specific
requirements. The information contained is only applicable
to the specific chemical compound identified in Section 1
General Information, 1.1 Product Identification. Mixtures or
compounds using styrene monomer will require additional
engineering studies to determine the applicability of the
enclosed information.
4.1 Bulk Storage
The construction of low-pressure styrene monomer storage
should be according to API-620 and 650 (see Appendix 4 for
citations). Higher-pressure storage vessels should comply with
ASME Code Section VIII, Division 1 or equivalent. All internal
surfaces should be kept clean and rust-free and should be
internally lined with inorganic zinc such as Carbozinc II or a
baked phenolic to prevent polymerization problems. Liquid
styrene monomer should enter through the bottom of the tank.
Incoming liquid should be prevented from free-falling through
the tank vapor space (see Section 8). Tanks should have a
minimum of internal beams, pipes and projections that can
provide places for condensed styrene monomer vapors to
accumulate and polymerize.
Refrigeration by external chillers may be required to
maintain the monomer temperature below 21°C (70°F). All
above-ground storage tanks should be insulated and designed
with a means of styrene monomer agitation. For a complete
discussion on storage conditions, see Section 8.
4.2 Piping
Piping and piping components should comply with the latest
edition of ASME/ANSI B31.3 or the appropriate equivalent.
Carbon steel is an acceptable material of construction although,
to prevent increased polymerization and color problems,
stainless steel is preferred. One and one half inch pipe or smaller
can use threaded, threaded and backwelded or socket welded
connections. Butt-welded fittings and flanged connections
are preferred.
Piping should be laid out to facilitate complete draining or
permit nitrogen purging back to the styrene monomer storage
tank or other common collection points. If lines are to be used
infrequently, complete draining is crucial. These lines should be
buried or shaded to minimize the potential for polymerization
due to temperature increases. For extended storage, all lines
should be designed to allow recirculation and chilling.
4.3 Electrical Area Classification
All electrical equipment should be suitable for flammable
organic liquids, be constructed and installed to recognized,
appropriate engineering codes of practice and conform to the
appropriate area classification.
4.4 Pump Specifications
Centrifugal pumps: any carbon steel or stainless steel type
designed with closed impellers and mechanical seals. Secondary
seals should be of Kalrez® 6375 or Chemraz® 505.
Rotary pumps: any type made for hydrocarbon service with
mechanical seals. Check pump regularly for gear wear.
Positive displacement pumps: any type made for
hydrocarbon service with mechanical seals. Check pump
regularly for wear.
Drum pumps: should be regularly checked for leakage and
cleaned thoroughly after each use.
When pumps are installed, care should be taken to avoid
the possibility of allowing a pump to run against closed valves.
“Deadheading” the pump will cause heat buildup and lead to
polymerization of the monomer; therefore, a minimum flow
line should be used. The line should have a cooler to keep
the styrene monomer below its polymerization temperature.
The pump design should also allow for complete drainage
and recirculation.
4.5 Instrumentation
Independent high-level alarms and/or shutdowns should be
provided for storage tanks. Storage tanks should be equipped
with temperature and level indicators. All instrumentation
should be designed, manufactured and installed to appropriate
engineering codes and conform to the appropriate area
classification. Avoid TFE coated-construction. TFE seals
are acceptable.
4.6 Relief Requirements
The requirements of API RP-2000 should be followed for
low-pressure vertical storage tanks. Pressure-relieving systems for
pressure vessels are defined in API RP-520, Parts 1 and 2.
Flame arresters, when required, should follow the requirements
of API R-2028 and 2210.
Pressure-relief valves in styrene monomer service should be
regularly inspected for polymer formation. A nitrogen purge
under the seat of the relief valve can be used to minimize
polymer buildup.
Avoid composite rupture disks with TFE seals. A nitrogen
purge under the seal of the relief valve can be used to minimize
polymer buildup.
Product Safety Bulletin 21
Engineering
4.7 Leak Detection Devices
4.8.5 Valve Packing
Secondary containment areas in confined spaces should be
monitored with instrumentation able to detect the lower
flammability limit of styrene monomer in air.
Instruments that have been successfully used to measure
styrene monomer are combustible gas indicators, infrared
spectrophotometers, flame ionization detectors and
photoionization detectors (see Section 3.4).
Die-formed rings: graphite-based
Bonnet gaskets: metal-reinforced, flexible graphite.
4.8 Material Requirements
4.9 Vapor Containment System
Styrene monomer, like other aromatics, is not compatible
with most elastomers and rubber materials. It is not compatible
with copper and copper alloys. Care should be taken when
selecting materials that will contact styrene monomer. Consult
with individual manufacturers about the specific needs of
your facility.
Vapor containment systems for pressure vessels are defined in
API RP-520, Parts 1 and 2.
4.8.1 Gaskets
Flat-ring (sheet): Durable nitrile, compressed fiber or Grafoil®
GHE with dimensions according to ANSI B 16.21.
Spiral-wound: Flexitallic CG or 100 percent graphite-filled with
dimensions according to API 601.
Avoid TFE piping gaskets. Teflon® gaskets used for truck or
other transport applications should be inspected regularly and
replaced as needed.
4.8.2 O-Rings
Kalrez, Viton®, Teflon, Fluorel® or equivalent. Avoid TFEencapsulated O-rings.
4.8.3 Pipe Thread Sealant
Teflon paste or tape. The continuity across connections should
be checked to ensure grounding.
4.8.4 Pump Seals
Component materials for mechanical seals should include:
Stationary Faces: tungsten carbide
Rotating Faces: carbon
Elastomers: Kalrez 6375 or Chemraz 505
Grafoil is a registered trademark of Graphtech Inc.
Kalrez and Viton are registered trademarks of DuPont Performance
Elastomers.
Fluorel is a registered trademark of Dyneon, LLC.
Chemraz 505 is a registered trademark of Green Tweed Company.
Teflon is a registered trademark of E.I. du Pont de Nemours and
Company.
22 Product Safety Bulletin
4.8.6 Hoses
All hoses should be flexible stainless steel, have suitable pressure/
temperature ratings and should be grounded to discharge static
electricity. All hoses should be tested on a regular basis.
4.10 Chemical Compatibility
Styrene monomer is highly reactive, especially with oxidizers,
peroxides, strong acids, metal halides and metal alkyls. Copper
and copper alloys should be avoided because their use can
discolor styrene monomer.
5. FIRE SAFETY
5.1 Fire and Explosion Hazard
5.2 Fire Prevention
Styrene monomer is classified by OSHA 29 CFR 1910.106
(see Appendix 4 for citations) as a Class IC flammable liquid.
The National Fire Protection Association (NFPA) Code 30 also
defines styrene monomer as a Class IC flammable liquid. For
application of the National Electric Code (NFPA 70), styrene
monomer is a Class I, Group D.
Styrene monomer has a flash point of 31.9°C (90°F).
Styrene monomer vapors are explosive in air at concentrations
between 1.1 and 6.1 percent by volume if an ignition source is
present (see Figure 5.1).
Styrene monomer vapor is heavier than air and may travel a
considerable distance to a source of ignition and then flashback.
All precautions necessary for the safe handling and storage of a
volatile flammable liquid or vapor should be strictly observed
with styrene monomer.
Uncontrolled polymerization should not occur if TBC
inhibitor levels, temperatures and dissolved oxygen are
controlled. However, if polymerization does occur, it causes heat
and pressure to increase. The resultant increase in heat and
pressure can cause storage containers to rupture and, if ignited,
explode. Polymer formation can lead to plugging of the relief
vents or equipment with an increase in fire and explosion risk.
Storage areas should be designed to prevent exposure of
styrene monomer to fire (see Section 8). Inhibitor levels should
be checked daily if styrene monomer is stored at temperatures
above 27°C (80°F). Section 8 contains further information on
TBC monitoring.
If styrene monomer is involved in a fire, unauthorized
individuals should be prevented from entering the area, and the
area downwind of the fire should be evacuated. All fires should
be fought from a safe distance upwind of the fire.
Styrene monomer fires produce carbon dioxide and may
produce carbon monoxide upon incomplete combustion. As it
decomposes, styrene monomer will emit acrid vapors and may
produce a powerful lacrimator (tear producing agent) upon
reaction with chlorine or bromine.
Heat may build pressure and rupture closed containers. A
water fog should be used to cool the containers. Water may be
ineffective as an extinguishing agent due to styrene monomer’s
low solubility. The flow of styrene monomer should be stopped
before trying to extinguish a fire. Liquid should be kept from
entering water sources and sewers by building dikes as necessary
to contain the flow. Proper authorities should be notified if
styrene monomer enters sewers or public water systems.
Styrene monomer can form explosive mixtures. Sources of
ignition including heat, sparks, flames and sources of static
electricity should be avoided. Each facility handling styrene
monomer should adopt a comprehensive program for fire
prevention. The following management systems contribute to an
effective fire prevention program:
• “no smoking” policy where styrene monomer is used
• the use of non-sparking tools while working with or near
equipment containing styrene monomer
• grounding metallic containers/vessels in which styrene
monomer is stored
• bonding and grounding metallic containers
• stringent welding, cutting and burning permit systems
• implementation of inside and outside storage methods
that comply with regulatory requirements and good
industry practice
5.2.1 Static Electricity
As with other flammable liquids, the transfer of styrene
monomer can create static electricity charges, which can act as
an ignition source for the flammable vapors. The charge can
develop when the liquid flows or is poured through air. To
reduce or eliminate this, bonding and grounding is required by
federal regulations (OSHA, 29 CFR 1910.106), building and
fire codes (NFPA 30, 70 and 77 and API RP-2003) and
industry practice.
Bonding provides a low-resistance path to current flow
between surfaces that are physically separated or become
separated.
According to NFPA 77, a maximum of one megaohm is
acceptable, but generally much lower values are possible.
Grounding connects the containment vessels and pipes
to a grounding electrode (ground) in the earth by means of
conductors welded or attached to both the equipment and the
grounding electrode. A 10-ohm maximum is the recommended
value for the resistance of the cable and ground.
Product Safety Bulletin 23
Fire Safety
5.3 Fire Suppression
5.4 Fire Fighting
Styrene monomer fires can be extinguished with dry chemicals,
halon, carbon dioxide and foams. For large fires, water spray or
fog may be effective. However, fixed-foam protection using an
application rate of 0.1 gallons per minute per square surface is
recommended. Several types of foam are effective. Manufacturers
should be contacted for specific recommendations.
Water may be ineffective in fighting styrene monomer fires.
Water can sometimes be used to extinguish styrene monomer
fires when several coordinated hose streams are used to sweep
the flames from the surface of the burning liquid. This approach
should be used only by experienced firefighters working under
favorable conditions. Water spray can also be used to disperse
vapors, protect firefighters, absorb heat and protect exposed
structures and adjacent storage areas.
Portable fire extinguishers should be placed near styrene
monomer storage and handling areas. Workers should be trained
in the use of portable fire extinguishers (29 CFR 1910.157).
Class B dry chemical or foam extinguishers should be used to
fight styrene monomer fires. Information on how to select, use,
distribute, inspect, maintain and recharge portable fire
extinguishers can be found in NFPA 10.
Facilities that rely on local fire authorities should provide them
with information on styrene monomer operations and storage,
including an illustration of storage locations and quantities of
styrene monomer present. Drills should be conducted
periodically with the local fire authority, and facility information
should be updated regularly.
Facilities using internal fire brigades should follow the
OSHA Fire Brigade Standard 29 CFR 1910.156. This standard
includes information on fire brigade organization, personnel
qualification, firefighting equipment and training requirements.
Firefighters should use full protective clothing and equipment,
including approved self-contained breathing apparatus (see
Section 3).
If a fire is controllable or styrene monomer containers are
not exposed to direct flame, an evacuation zone with a
minimum radius of 1,500 feet may be needed. If the fire
becomes uncontrollable or styrene monomer containers are
exposed to direct flame, an evacuation zone with a minimum
radius of 3,000 feet may be required.
After a fire has been extinguished, any residual styrene
monomer should be cleaned up to prevent another fire or
environmental contamination. Individuals involved in a
cleanup should be thoroughly trained in proper techniques
according to the OSHA Hazardous Waste Operations and
Emergency Response (HazWOpER) Standard 29 CFR
1910.120. Refer to Section 7 for additional information on
environmental considerations.
Figure 5.1 Flammability Region* for Styrene Monomer Storage
10
Concentration in Air (Volume %)
9
8
7
Upper Flammability Limit
6
5
4
3
2
1
0
Lower Flammability Limit
0
10
20
30
40
50
Storage Temperature (°C)
60
70
80
Minimum Oxygen for Combustion (MOC) – 9.0 percent
*This is the region where flammable vapors exist over styrene monomer liquid at atmospheric pressure.
24 Product Safety Bulletin
6. HAZARD COMMUNICATION
6.1 OSHA Hazard Communication
Under Hazard Communication and Right to Know Laws,
workers and communities should be informed of the potential
hazards of styrene monomer. At the federal level, the OSHA
Hazard Communication Standard 29 CFR 1910.1200 (see
Appendix 4 for citations) requires that employers who use
hazardous chemicals, including styrene monomer, in their
workplace develop written programs and train workers on the
potential hazards and protective measures.
6.1.1 Worker Training
As a user of styrene monomer, an employer must provide
information and training on its hazards for workers, the
methods for detecting releases and methods of protection from
exposure. This information should be included in the Hazard
Communication Training Program required by OSHA 29 CFR
1910.1200. To assist in this effort, the following summary
information is provided.
6.1.1.1 Hazards
Styrene monomer is a highly flammable liquid with a
moderately high boiling point and a low vapor pressure. The
vapors of styrene monomer are heavier than air and may travel
long distances along the ground. These vapors are flammable
and will burn or explode. Styrene monomer is very reactive and
may self polymerize producing heat and pressure. Avoid contact
with heat, flame, oxidizers, peroxides, strong acids, aluminum
chloride, metal halides and metal alkyl. It is corrosive to copper
and copper alloys and will dissolve many natural and synthetic
rubbers.
The major hazard associated with repeated daily exposure to
low levels of styrene monomer is related to styrene monomer’s
effect on the CNS causing drowsiness, listlessness, nausea and
loss of appetite.
Skin contact, depending on concentration and duration of
exposure, may cause moderate irritation and dermatitis. Eye
contact with liquid styrene monomer may cause moderate
irritation, including a burning sensation and tears. High vapor
concentrations may also cause eye irritation.
The International Agency for Research on Cancer (IARC)
classified styrene monomer as a “possible human carcinogen”
(Class 2B). The EPA has not classified styrene monomer, and
OSHA has determined that there is insufficient evidence to
classify this product.
For a complete discussion of the health effects of styrene
monomer, see Section 2.
6.1.1.2 Methods of Detection
good warning properties. Styrene monomer has a sweet,
aromatic odor.
To determine worker exposure to styrene monomer in air,
measurements can be made using air-sampling equipment.
A variety of instruments are available to provide instantaneous
or continuous monitoring of styrene monomer concentrations
in air.
Direct-reading instruments including combustible gas
indicators, infrared spectrophotometers, flame and
photoionization detectors and colorimetric detector tubes
can be used to monitor for styrene monomer (see Section 3.4).
When assessing worker exposure to styrene monomer,
personal breathing zone samples should be collected to
determine compliance with the established exposure limits
(see Section 3.5).
6.1.1.3 Methods of Protection
Hazard communication training must include information on
methods of protection that can be used by workers handling
styrene monomer. This should include the engineering and
administrative controls employed, as well as the PPE to be worn
(see Sections 3.3 and 3.4).
6.1.2 Labeling
All incoming containers of styrene monomer are accompanied
by a product label providing health and safety information.
The product label is a primary source of information for safe
handling of this material. Lyondell Chemical Company product
labels contain the material identification, principal hazards
and Company’s name, address and telephone number (see
Figure 6.1).
Containers of styrene monomer or mixtures containing
styrene monomer in concentrations greater than or equal to
0.1 percent must be labeled according to the OSHA Hazard
Communication Standard. The DOT labeling requirements for
styrene monomer are presented in Section 11.2.
Each vessel into which styrene monomer is transferred
should be clearly identified as to its contents and the hazards
of the materials it contains. Many firms elect to employ the
United States National Fire Protection Association (NFPA) 704
Standard System for the Identification of the Fire Hazards of
Materials (Hazard Diamond) as a means of in-plant
communication to workers, contractors and firefighters. The
appropriate numerical hazard classifications for styrene
monomer are as follows:
• Health (Blue): 2
• Fire (Red): 3
• Reactivity (Yellow): 2
Because styrene monomer can be detected via odor at
concentrations as low as 0.14 ppm, it is considered to have
Product Safety Bulletin 25
Hazard Communication
6.1.3 Material Safety Data Sheets
6.2 SARA Title III
Operational Excellence and legislation in most countries,
(e.g. Directive 91/155/EEC) require that customers,
transporters, etc. should be given the appropriate, necessary
information on a chemical’s hazards and the precautions/
remedial actions required. This is done through the MSDS, and
Lyondell Chemical Company ensures that, as a minimum,
provision of such data complies with the requirements of the
countries in which they operate. A Lyondell Chemical Company
MSDS is provided with the first order and after any change or
revision to the MSDS. In some regions, an additional issue is
also under­taken with the first delivery of a new year.
The MSDS is a primary means of providing information
regarding the safe storage, handling, use and ultimate disposal of
Lyondell products.
While the product MSDS is an invaluable source of health
and safety information, it may not supply information specific
to the actual uses of the product. When the information
provided does not adequately fulfill your needs, contact your
local Lyondell sales representative, regional sales office or call
Customer Service at (888) 777-0232.
Lyondell Chemical Company MSDSs are available in several
languages and formats. While the additional downstream sales
of styrene monomer or materials containing styrene monomer
are the responsibility of the distributor, Lyondell Chemical
Company will support your hazard communication efforts.
The Emergency Planning and Community Right to Know Act
of 1986, also referred to as the Superfund Amendment and
Reauthorization Act or SARA Title III, requires facilities that
use or store styrene monomer to notify their state emergency
response commissions and work with local authorities to
develop emergency response plans. Users of styrene monomer
should read the SARA Title III regulations and familiarize
themselves with its requirements.
Because styrene monomer is a potentially hazardous
chemical, facilities should submit a copy of their MSDS or
their chemical inventory list to their local emergency planning
committee (LEPC). This inventory listing should include
all mixtures of styrene monomer in excess of 0.1 percent
concentration.
Lyondell Chemical Company uses values known as
Emergency Response Planning Guidelines (ERPGs) to assist
in developing strategies for protecting workers and the general
public against the harmful effects of styrene monomer.
The proposed ERPG values are: ERPG 1 = 50 ppm,
EPRG 2 = 100 ppm and ERPG 3 = 1000 ppm. It is believed
that all individuals could be exposed to up to 50 ppm for nearly
an hour without experiencing any mild or adverse health effects,
while 250 ppm is a level in which nearly all individuals could be
exposed for up to one hour without experiencing or developing
any irreversible health effects that could impair one’s ability to
take action. At 1000 ppm, individuals could be exposed for up
to an hour without developing life-threatening effects.
6.3 State Regulations
State or local regulations are based on the federal legislation, but
may have different or more stringent requirements. Facilities
should review specific state regulations to assess their
applicability to the use of styrene monomer (see Appendix 5).
26 Product Safety Bulletin
Hazard Communication
Figure 6.1 Styrene Monomer Label Information
Manufacturer: LYONDELL CHEMICAL COMPANY
1221 McKinney
Houston, TX 77010
Telephone Numbers
EMERGENCY
(800) 424-9300 Chemtrec
(713) 652-7200
CUSTOMER SERVICE
(888) 777-0232 Info Only
SCID
(800) 245-4532
Use Statement: For industrial use only.
Keep out of the reach of children.
Signal Word: Danger.
Physical Hazards: Highly flammable.
Reactive, unstable unless inhibited.
Health Hazards: Mucous membrane irritant.
Skin and eye irritant.
Ingestion hazard.
Precautionary Measures: Avoid high temperature and shocks.
Material is unstable, and hazardous polymerization may occur.
Do not handle near heat, sparks or open flame.
Keep containers closed when not in use.
Do not store near combustible materials.
Avoid contact with eyes, skin and clothing.
Avoid prolonged or repeated breathing of vapor.
Use only with adequate ventilation/personal protection.
Prevent contact with food, chewing or smoking materials.
DOT Information: UN/NA ID Number - UN 2055
Hazard Class: Flammable Liquid
Proper Shipping: Styrene Monomer, Inhibited (RQ 1000 lbs/454 Kg)
Component Name: Styrene (CAS Number 100-42-5)
4-tert-Butylcatechol (CAS Number 98-29-3)
In case of fire: Dry chemical, CO2, foam
First Aid
Inhalation: If overcome by exposure, remove victim to fresh air immediately. Give oxygen or
artificial respiration as needed. Obtain emergency medical attention. Prompt action is
essential.
Eye Contact: For even minor eye contact, immediately rinse with clean water for 20–30 minutes.
Retract eyelid often. Obtain emergency medical attention. Prompt action is essential.
Skin Contact: Immediately remove contaminated clothing. Flush with lukewarm water for 15 minutes.
Wash skin thoroughly with mild soap and water. Seek medical attention if ill effect or
irritation develops.
Ingestion: If a large quantity is swallowed, give lukewarm water (pint) if victim is completely conscious/
alert. Do not induce vomiting, as risk of damage to lungs exceeds poisoning risk. Obtain
emergency medical attention.
In case of spill: Release can cause a fire and/or explosion hazard. May polymerize and release heat and
gases. Extinguish all ignition sources. Blanket with firefighting foam. Impound and recover
large land spills if safely possible. Soak up small spills. On water, contain, minimize
dispersion and collect if safely possible. Report per regulatory requirements.
ProtectivE Equipment
Respiratory apparatus: Use NIOSH/MSHA-approved air-purifying or supplied air respirator as appropriate.
Eye: Chemical splash goggles and/or face shield.
Skin: Protective clothing including gloves, apron, sleeves, boots and full head/face protection.
Product Safety Bulletin 27
7. ENVIRONMENTAL
Styrene monomer is an extremely flammable and slightly
volatile liquid at ambient temperatures. Spills and leaks require
prompt response to minimize the risk of fire and/or explosion,
as well as fugitive air emissions. Styrene monomer has a
reportable quantity (RQ) of 1,000 pounds. for spills under the
Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA), and annual reporting is required under
40 CFR 372 (Toxic Chemical Release Reporting: Community
Right-to-Know – see Appendix 4 for citations).
Styrene monomer is slightly soluble in water and is soluble
in most organic solvents. It is biodegradable by acclimatised
bacterial populations, but surface waters and wastewater
treatment plants should be protected from spills. The primary
removal mechanism of styrene monomer from water is most
likely volatilization, as indicated by its relatively high Henry’s
Law Constant (2.83 x 10-3 atm/mol•m3). The primary
mechanisms for styrene monomer removal from soils are
biodegradation, solubilization by infiltrating water and, in
shallow soils, volatilization.
Based on its low water solubility and the magnitude
of its organic carbon partitioning coefficient (calculated
KOC= 260-550), styrene monomer’s mobility in soil is
considered to be moderate to low.
Limited bioconcentration experiments indicate that styrene
monomer has a relatively low bioconcentration factor,
suggesting that it should not bioaccumulate in animals and
plants to any significant extent.
7.1 Air Quality Considerations
7.1.1 Clean Air Act
Styrene monomer is classified as a Volatile Organic Compound
(VOC) under the Clean Air Act (CAA). In addition, styrene
monomer has been listed as a Hazardous Air Pollutant (HAP)
under the Clean Air Act Amendments of 1990 (CAAA). These
two classifications are the principal areas under which air
emissions of styrene monomer will be regulated. Facilities with
the potential to emit styrene monomer may be subject to the
CAAA. (Consult with federal, state and local officials to
determine other air regulations that may apply.)
The EPA has designated various Air Quality Control
Regions (AQCR) of the country as either Attainment, Nonattainment or Unclassified for ozone. As a VOC, styrene
monomer is subject to the new regulations for ozone nonattainment areas. These regulations require emission controls on
industrial sources of VOCs.
As a HAP, styrene monomer is subject to regulations by
industrial category rather than as an individual compound.
Major source facilities in the regulated categories will be
required to install Maximum Achievable Control Technology
(MACT) and may also be required to adopt process, material or
work practice changes to minimize emissions. (Major sources
emit 10 tons per year of any single air toxic or 25 tons per year
of any combinations of air toxics.)
7.1.2 Toxic Chemical Release Inventory
Styrene monomer is among the chemicals listed in the
Superfund Amendments and Reauthorization Act (SARA)
Title III, Section 313 (40 CFR 372). Facilities subject to these
regulations are required to submit annual reports listing the
quantities of styrene monomer emitted from point sources and
as fugitive emissions.
7.1.3 State Requirements
All states which contain National Ambient Air Quality
Standards (NAAQS) non-attainment areas are required to revise
their State Implementation Plans (SIPs) under the CAAA.
Styrene monomer will thus be regulated by individual states
to meet the requirements of CAAA. In addition, states may
enforce more stringent air emission requirements than the
federal standards.
7.2 Clean Water Act
The discharge of wastes containing styrene monomer to waters
of the United States is regulated under the National Pollutant
Discharge Elimination System (NPDES) permit program of
the Clean Water Act (CWA). Styrene monomer is listed as a
hazardous substance under Section 311 (b)(4). Federal Water
Quality Criteria for the protection of human health and/or
aquatic organisms have not been developed for this compound.
Styrene monomer is thus subject to case-by-case determination
of NPDES permit limits.
Styrene monomer is a regulated organic contaminant under
the Safe Drinking Water Act. It has a maximum Containment
Level (MCL) of 100 µg/L and is subject to regulation in public
water systems.
7.2.1 State and Local Water Quality Criteria
The direct and indirect discharge of “toxic” pollutants to waters
of a state may be regulated by state surface water quality criteria
and/or effluent limitations, as well as local publicly owned
treatment works (POTW) pretreatment requirements.
Pretreatment requirements are mandated under federal law to
prevent the discharge of pollutants that may create a fire or
explosion hazard in sewers or at the POTW that may pass
through the POTW or interfere with its normal operations.
Applicable state and local regulations should be consulted.
Product Safety Bulletin 29
Environmental
7.2.2 Categorical Standards
7.3.2 Waste Classification
Styrene monomer is not specifically regulated under categorical
effluent standards, but may be regulated as a component of
chemical or biochemical oxygen demand (COD or BOD) or
total organic carbon (TOC).
Wastes containing styrene monomer are not “listed hazardous
wastes” under the RCRA, but styrene monomer-containing
materials may be hazardous under RCRA by virtue of the
characteristics of ignitability.
Styrene monomer wastes are considered characteristically
hazardous if the flash point of the material is below 140°F.
Hazardous wastes may include, but are not limited to, process
wastes containing styrene monomer, styrene monomercontaminated water, soil and debris and empty containers
(see 40 CFR 261).
7.3 Waste Management
7.3.1 Spills and Leaks
If possible, all pumps and ancillary equipment should be located
outside the primary containment area and should be provided
with curbing to collect drips, leaks and minor spills.
In the event of a styrene monomer release of 1,000 pounds
or more to the environment, the National Response Center
must be notified. The telephone number of the National
Response Center is (800) 424-8802. The reporting requirement
is due to the listing of styrene monomer as a hazardous
substance under CERCLA Section 302. Styrene monomer users
should also be familiar with any state and local reporting
requirements for styrene monomer.
Accidental discharges of styrene monomer or process waste
containing styrene monomer into the public sewer system or
waterways should be immediately evaluated and, if required,
reported to local authorities. The discharge should be diluted
with copious quantities of water to reduce the fire and explosion
hazard.
In the event of a spill of styrene monomer, all non-essential
personnel should be evacuated and all ignition sources
extinguished immediately. After donning the appropriate
personal protective equipment (see Section 3), the spill can be
covered with firefighting foam (see Section 5.3) to minimize
emissions and the potential fire hazard. Depending on the
volume and location of the spill, it can be recovered by vacuum
truck or adsorbed with solid sorbent and placed in appropriate
containers for disposal. Spills into surface water may be cleaned
up using a skimmer or vacuum system. Styrene monomer floats
on water and also tends to polymerize to form a surface glaze.
All power equipment used in cleanup must meet National
Electrical Code (NFPA 70) requirements of Class I, Group D
areas. The use of water for cleanup should be minimized, but
residual styrene monomer should be flushed with water into
sump or collection area for subsequent treatment or disposal.
Soil contaminated with styrene monomer that exhibits
one or more of the hazardous characteristics of 40 CFR 261
should be excavated and transported to an authorized, secure
hazardous waste treatment or disposal facility. Other materials
contaminated with styrene monomer may be ignitable and
should be treated as hazardous until proven otherwise.
30 Product Safety Bulletin
7.3.3 Waste Handling and Storage
The handling and storage of hazardous materials are regulated
by OSHA and EPA. OSHA regulation 29 CFR 1910.120
Hazardous Waste Operations and Emergency Response
(HazWOpER) applies to the handling of spills of styrene
monomer. This regulation applies to personnel engaged in
hazardous waste storage, hazardous waste sites and emergency
response. EPA regulations 40 CFR 260-272 apply to the
storage, handling, transportation and disposal of hazardous
wastes. Users of styrene monomer who generate, store, reclaim
or tender for transportation and disposal any hazardous waste
should review these regulations.
Hazardous waste may be held on site for up to 90 days
(for generators of small quantities up to 180 days and under
certain circumstances 270 days) without a RCRA permit
provided that the waste is placed in approved containers and
stored in clearly identified areas. Exceptions for generators of
small quantities (100-1000kg) are found in 40 CFR 262.
Hazardous waste storage areas must be designated so that any
spillage of waste is collected. Containers stored in such facilities
must be clearly labeled, dated and checked at least weekly (see
40 CFR 264 and 265) for deterioration of containers and
containment system caused by corrosion or other factors. If the
facility is not exempt as a small-quantity generator, detailed
records must be kept. State regulations may specify additional
design require­ments for temporary hazardous and nonhazardous waste accumulation areas.
Environmental
7.3.4 Waste Treatment and Disposal
Styrene monomer wastes are not hazardous by (RCRA)
definition and may be disposed of either by burning as fuel or
by transfer to a permitted disposal facility. Solid wastes may be
landfilled or incinerated. Liquid wastes may be treated in an
on-site waste­water treatment plant if this will not cause plant
upset or violate the NPDES permit limits. They may also be
sent to a POTW with local authority approval. Dilute styrene
monomer has been shown to be biodegradable under aerobic
conditions in a number of studies.
Characteristic hazardous wastes containing styrene
monomer require disposal at permitted facilities in accordance
with RCRA requirements. Hazardous wastes must be treated as
specified in the Land Disposal Restrictions (40 CFR 268) prior
to their management in a land-based system (e.g. landfill or
surface impoundment). Liquid wastes should be collected for
incineration, burning as fuels or other treatment. All burning of
hazardous waste fuels containing styrene monomer must be in
accordance with RCRA and 40 CFR 266. Water contaminated
with styrene monomer may be treated by air stripping, chemical
oxidation or granular activated carbon (GAC). Vented styrene
monomer vapors should be captured by a condenser.
Containers used to hold styrene monomer must be drained
and then thoroughly rinsed to be considered nonhazardous.
Rinsate generated by this washing should be collected and
properly disposed. Although not required, it may be desirable to
complete a certificate of cleaning, which documents that the
containers have been appropriately cleaned and can be reused.
Any container that has not been completely water-washed
should be considered a potential fire or explosion risk and
should not be burned, soldered or welded.
Product Safety Bulletin 31
8. PRODUCT STORAGE
Considerations in the design and construction of styrene
monomer storage and handling facilities are flammability,
potential to polymerize, environmental contamination and
worker exposure. The specific requirements for storing
and handling styrene monomer depend on several factors,
including volumes stored or handled, container type, mode
of transportation, processes used at the facility and the
proximity to other hazardous materials. The proper design
and construction of storage and handling facilities requires
consultation with competent professional engineers.
Additional requirements may be imposed by the OSHA
Process Safety Management of Highly Hazardous Chemicals
29 CFR 1910.119 (see Appendix 4 for citations). The standard
applies to processes involving flammable liquids in quantities of
10,000 pounds or more.
Styrene monomer is highly reactive and, therefore, different
from other common aromatic compounds in that it will
polymerize. Styrene monomer polymerizes slowly at room
temperature and more rapidly at elevated temperatures. Polymer
formation may be accelerated by any of the following:
• depleted inhibitor concentration
• high temperatures
• acids
• peroxides
• oxidizers
• other catalysts such as dirt and scale
• insufficient dissolved oxygen levels
The rate of polymerization can become uncontrollable. This
can lead to hardening and plugging of equipment or, in the
worst cases, a fire or explosion. To prevent polymer formation
in styrene monomer, TBC inhibitor is typically added at a
concentration of 10-15 ppm. In addition to using TBC,
temperature control and proper selection of a storage
environment should ensure shelf life with the necessary
quality specifications.
8.1 Drum Storage
Indoor storage of styrene monomer should typically be
constrained to drum-sized or smaller packagings. Storage should
follow the regulations and guidelines for storage of flammable
liquids, such as NFPA 30 and 29 CFR 1910.
The two most significant considerations for storage of drums
containing styrene monomer are temperature and time. Drums
of styrene monomer should be kept out of direct sunlight and
away from any sources of heat. Preferably, the styrene monomer
drums will be kept in an air-conditioned warehouse or even a
chilled room. Even where such precautions are possible and
especially where they are not, the time duration that styrene
monomer is held in inventory must be closely monitored
(see Table 8.1).
Styrene monomer may be safely stored in steel drums.
However, to minimize the risk of premature polymerization, the
drums should be lined with a compatible impervious lining.
Rust and scale from an unlined drum may promote
polymerization of the styrene monomer.
If drums containing styrene monomer are observed to be
warmer than ambient air temperature, then styrene monomer
polymerization may be occurring. The drums should be
immediately cooled using a water spray until the temperature of
the drums has stabilized. Drum temperatures should then be
closely monitored until the material can be used or disposed.
8.2 Storage Tanks
When designing bulk storage facilities for styrene monomer,
certain factors should be considered. In addition to normal
precautions taken for flammable liquids against fire and
explosion hazards, care must be taken to avoid conditions
that could cause polymerization and oxidation. Tanks and
distribution systems should be designed to eliminate excessive
temperatures and contamination from polymer residue left in
infrequently used lines and pumps. Additional design features
should include inhibitor addition, tank content sampling and
recirculation, tank breathing and control of vapor emissions.
Product Safety Bulletin 33
Product Storage
8.2.1 Tank Construction
Atmospheric styrene monomer storage tanks should be designed
and constructed according to NFPA 30 as it applies to Class IC
liquids and API 650 as a minimum. API 620 is also acceptable.
This API standard is intended to ensure that tanks possess
sufficient structural strength and pressure-relief systems to
prevent catastrophic loss of contents either in normal service or
under fire conditions. A typical storage tank for styrene
monomer can be seen in Figure 8.1.
Proper storage conditions are essential to ensure good
styrene monomer quality with minimal polymer formation. The
storage tank should be clean, constructed of steel with a selfsupporting dome roof for vertical storage tanks. Styrene
monomer vapors are not inhibited and can form polymer. The
ceiling of the storage tank should be smooth and free of internal
superstructure to eliminate sites for polymer formation. Keep an
absolute minimum of internal beams, pipes, projections and
crevices that can provide places for condensed styrene monomer
vapors to accumulate and polymerize. In addition, it is
recommended that all internal structural connections be welded.
Tank cleanliness is important, as dirt and scale may act as
catalysts for polymer formation. Copper and copper-bearing
alloys such as brass, bronze and Monel® should be avoided
because copper will react with the TBC and impart a bluishgreen color to the styrene monomer.
Openings in the roof and sidewalls above normal liquid
levels should be of large diameter, and the number should be
kept to a minimum. Large-diameter openings facilitate easy
cleaning and dual-purpose use, where feasible.
Tank openings such as vents, arrester plates and man-ways
should be inspected every six months for polymer buildup. If
polymer buildup occurs, it is a good indication that more serious
polymer formation in the form of stalactites on the tank roof
may be occurring. The polymer buildup should be removed.
Tank linings have proven quite successful in controlling
polymerization problems in styrene monomer storage. Liners
will cover any scale and oxidation and prevent future scale. A
tight, nonporous, non-wettable smooth surface allows the
uninhibited styrene monomer vapor condensate to return
quickly to the inhibited liquid monomer before polymerization
can take place. Baked phenolic, carbon-zinc, modified epoxy
and catalyzed epoxy linings have all been used for this type of
service. However, these lining are all nonconductive and, at a
minimum, the lower portion of the storage tank should be lined
with a conductive coating that provides electrical grounding.
Inorganic zinc silicate linings have been used for years in styrene
monomer service, giving both the conductivity and smooth
surface desired. Other comparable linings are available, and the
manufacturers of the coating should be consulted for
performance and application information. Rubber-based
coatings should not be used.
The styrene monomer storage tank can be filled from the
bottom or top. When using a top-fill line, the line should be
extended inside the tank to the bottom so as to prevent static
electric discharge. The fill outlet should be below minimal
operating level.
34 Product Safety Bulletin
Circulation is recommended for all styrene monomer
storage tanks to facilitate thorough mixing when new monomer
or inhibitor is added, to help control monomer temperature
and to maintain the required dissolved oxygen in the system.
Circulation of tank contents may be achieved by using a swing
pipe design or an eductor. For the swing pipe design, the outlet
line operates through a floating swing pipe adjusted so the
monomer is always withdrawn a few inches below the surface.
Warm monomer is withdrawn from the top, circulated and
discharged at the bottom of the tank. The other mixing option
is to install an eductor inside the tank on the discharge end of
the recirculation line. Mixing improves temperature uniformity
of the monomer and ensures that samples are representative of
the tank’s content. The inlet line and outlet line should be at
opposite ends of the tank.
Valves located below liquid level must be designed to
prevent breakage from freezing, heat shock or mechanical stress.
Lubricated plug cocks and non-lubricated ball valves lined with
Viton are satisfactory. Stainless steel ball valves have been used
for styrene monomer service. All valves require routine
maintenance to prevent plugging.
Considerations in site selection and tank spacing include
proximity to other flammable material storage facilities, nearby
sources of ignition, accessibility for firefighting and the impact
of a vapor cloud explosion on nearby areas. Bulk storage tanks
should have fire monitors to provide cooling in the event of an
external fire.
Article 500 of NFPA 70 (NEX) outlines electrical
requirements for handling, transport and storage of styrene
monomer and other Class IC flammable liquids. It also requires
that, whenever flammable liquids are stored or transferred, their
containers should be effectively bonded and grounded to
prevent static electricity.
Storage tanks should be situated within containment
systems that are capable of providing detection and control of
an accidental release of styrene monomer from any tank surface
and from piping to and from the tank. Containment-system
design and operation should conform with NFPA 30. Tanks
must also be designed to provide complete drainage. Separate
drain lines, a small built-in sump with a bottom drain and floors
sloped to the drains are important for complete drainage.
8.2.2 Tank Breather Vents
Tank breather systems should be designed to minimize the
emission of vapors. Unloading piping should include an
equalization or vapor return line to exchange displaced vapors
between the storage tank and the unloading vehicle. Tankventing and emergency relief should comply with API 2000.
When designing large storage tanks, it should be noted that it is
impractical to install sufficient relief capacity in the event of a
runaway polymerization. Therefore, it is critical to maintain the
correct inhibitor and oxygen concentrations, control tank
temperature and provide tank circulation.
Monel is a registered trademark of Special Metals Corporation.
1
LI
3
LS
LA
6
TI
10. SWING JOINT
5. LEVEL ALARM HIGH/LOW
TT
12
TI
6
13
H
TS
1
H
16
See Section 8.2.4
INHIBITOR
ADDITION
POINT
15. FOAM CHAMBER/FOAM MAKER
14. TEMPERATURE ALARM HIGH
13. TEMPERATURE SWITCH HIGH
12. TEMPERATURE TRANSMITTER
11. MIXING EDUCTOR/S
10
11
14
TA
FOAM
PI
19
20
17
TO PROCESS
20. CHECK VALVE
19. PRESSURE INDICATOR W/SEAL
18. PUMP
17. GROUND WIRE
16. STRAINER
17
18
M
REFRIGERATION SYSTEM
SEE N.F.P.A. 11 STANDARD FOR LOW EXPANSION
{ FOAM
AND COMBINE AGENT SYSTEM
6 TI
15
*This figure illustrates a typical configuration and is not intended to be used as a design specification.
Qualified professionals must exercise engineering judgment to establish site specifications that meet the applicable requirements.
9. SUCTION LINE AND FLOAT
. NFPA IDENTIFICATION CODE
6. TEMPERATURE INDICATOR
Sloped
M
8
9
4. LEVEL SWITCH HIGH/LOW
7
STYRENE
Liquid Level
8. MANWAY
2
LT
4
5
3. LEVEL INDICATOR
2. LEVEL TRANSMITTE
1. CONTAINMENT DIKE
OR BARGE
FROM
IMO TANK (Fig. 9-8)
TANK TRUCK (Fig. 9-6)
TANK CAR (Fig. 9-1)
L
H
L
H
TI
6
BREATHER
AND VENT
SYSTEM
See Section 8.2.2
RECYCLE
VAPOR
CONTROL
SYSTEM
See Section 8.2.3
Product Storage
Figure 8.1 Typical Atmosphereic Storage Tank Configuration*
Product Safety Bulletin 35
Product Storage
Figure 8.2 Decrease of TBC Concentration in Styrene Monomer
20
Initial
18
Concentration
TBC Concentration (ppm)
16
10 ppm
14
15 ppm
12
20 ppm
10
8
6
4
DO NOT ALLOW TO FALL BELOW THIS LIMIT
2
0
0
2
4
6
8
10
12
14
Weeks at Room Temperature 19oC (68oF)
8.2.3 Control of Vapor Emissions
Bulk storage tanks should be vented to a vapor collection and
containment system that effectively eliminates discharges of
styrene monomer vapors to the atmosphere. The exchange of
vapors between the bulk delivery vehicle and the storage tank
through an equalization line may be used. Different types of
vapor recovery systems are available. These include carbon
adsorption beds, condensers, incinerators, flares and thermal
oxidizers. Emission reductions may be achieved by reducing
tank temperatures. The venting or collection system should be
designed to prevent the passage of a flame or explosion from
one container to another.
8.2.4 Inhibitor Control
Lyondell Chemical Company adds 4-tert-Butylcatechol to all
styrene monomer. It acts as an inhibitor to prevent polymer
formation. The standard addition rate is 10-15 ppm. This level
of inhibitor permits the use of styrene monomer in most
applications while still providing good shelf life. Higher levels of
TBC may be added to meet customer specifications. Another
important factor for product stability is the effect of TBC
depletion over time in styrene monomer. Table 8.1 shows
maximum recommended storage times as a function of tank
contents temperature. This table should be considered only a
guideline, as other factors will also influence stability.
36 Product Safety Bulletin
Table 8.1 Styrene Monomer Storage Time*
Temperature
Frequency of
TBC Monitoring
Storage Time
35°C/95°F
Daily
3 days
29°C/85°F
Daily
2 weeks
24°C/75°F
Twice a week
5 weeks
18°C/65°F
Weekly
3 months
*TBC levels maintained at 15 ppm
The levels of 4-tert-Butylcatechol should be monitored on a
routine basis (see Table 8.1 and Appendix 6).
Polymer and color analyses should be conducted at the same
frequency as the TBC analysis. The preferred method for
4-tert-Butylcatechol analysis is the ASTM Method D-4590. A
Visual Quick Test Method is provided in Appendix 6 for use
when rapid test results are justified.
If TBC levels fall below 10 ppm, inhibitor should be added
to bring the level up to 10-15 ppm. The 4-tert-Butylcatechol
concentrations should never fall below 4 ppm. Depending on
tank conditions, incipient polymerization may occur at this
level. This is evidenced by a slight increase in styrene monomer
viscosity and/or temperature. Polymer formation is shown by
diluting one part of styrene monomer with 10 parts methanol
and observing a cloudy solution. The exact polymer level can be
determined using ASTM Method D-2121, Method A.
Product Storage
The 4-tert-Butylcatechol levels will be depleted if tank
temperatures are too high (see Figure 8.2). Tank temperatures
should generally be maintained below 21°C (70°F). Lower
temperatures are recommended if styrene monomer will be
stored for extended periods. Tank temperatures can be reduced
in warmer climates by tank insulation, reflective painting and
circulation. Refrigeration should be provided when no other
means exist to maintain tank temperatures below 21°C. Tanks
should be equipped with recirculation lines and pumps to aid in
cooling, in addition to providing mixing and dissolved oxygen
requirements. Recirculation of process and offloading lines
should be considered where there is a potential for extended
holdup of material. Temperature indicators should be provided
at various levels in the tank. If infrequent temperature checks are
made, a temperature alarm system may also be provided.
The 4-tert-Butylcatechol inhibitor requires dissolved oxygen
to work effectively. The minimum required dissolved oxygen
level in styrene monomer is approximately 20 ppm. This can be
maintained easily by recirculation of the styrene monomer in an
air blanketed storage tank at least three to four times per week.
If oxygen is totally removed from a storage tank by using a
nitrogen blanket, dissolved oxygen will be removed and TBC
becomes ineffective, leading to polymerization. Nitrogen
blanketing is only recommended for short-term storage. If an
inert gas is used as a blanket for extended storage, the oxygen
content in the vapor phase should be controlled between 2 and
6 volume percent. This oxygen content will provide sufficient
dissolved oxygen for TBC as well as prevent flammability. An
oxygen analyzer may be useful to maintain proper oxygen
content under this storage condition.
When TBC addition is needed, it can be made most
easily by adding a TBC solution of 85 percent TBC and
15 percent methanol supplied directly by the manufacturer.
It may be added through the suction line of the recirculation
pump. Each 20,000 liter increment of styrene monomer
should have 210 gm of TBC solution added to an approximate
10 ppm TBC concentration. The TBC will only be effective
when the tank is circulated and thoroughly mixed. Lyondell
Chemical Company has TBC available at all terminal facilities
to adjust the level to specific customer requirements.
8.3 Unloading Installations The installation for unloading rail tank cars and tank trucks of
styrene monomer should be designed, maintained and operated
to meet current standards for fire protection, worker safety and
environmental safety.
Loading racks should be located at least 150 feet from all
equipment and tanks according to NFPA 30. Electrical wiring
and devices should comply with NFPA 70. Piping throughout
the installation should comply with NFPA 30 or with ASME/
ANSI B31.3. Piping systems for tank trucks and tank cars
should be connected to a common earth ground and bonded to
the discharge system. Continuity to ground should be checked
prior to unloading.
According to API 2350, instrumentation at the loading
station should warn the operator of the potential for overfilling
and shut off flow whenever overfill is imminent. Neither
device is to be used as a regular operating tool for determining
tank level.
Styrene monomer collection systems should be large
enough to contain the worst credible accidental release of
styrene monomer, plus an additional volume for flush water and
rain water. The unloading area should be curbed to divert
spillage into the drainage system and prevent run-off into the
surrounding areas. Adjacent unloading areas should be
segregated by curbing. At a minimum, the surface of the
unloading area under and around the bulk-transport vessel
should be constructed with an impermeable membrane or
ballast installed over an impermeable barrier suitable for the
retention of styrene monomer. The drainage surfaces should be
pitched with a grade of at least 1 percent toward the collection
basin or sump.
The sump or catch-basin should have fire seals and should
be equipped with instruments that will reliably detect liquid
levels and the presence of styrene monomer vapor. Rain water
and spills trapped inside the containment area are to be disposed
of through the sump or catch-basin. Discharge valves from the
collection area should be closed under normal conditions.
Accumulated liquids should be disposed of only by a trained
operator after determining the liquid’s composition.
Lighting adequate for nighttime unloading operations
should be provided, unless all unloading will be done
during daylight.
A suitable method of discharging container contents should
be provided. Acceptable methods include gravity flow, pumping
from the top through a dip pipe or pressurization with nitrogen.
If nitrogen pressurization is used, the facility should be designed
to avoid over-pressurization of the vessel. Furthermore, a
means of collection and environmentally acceptable treatment
of the vapor (e.g., flaring or scrubbing) should be provided.
Vapor containment systems should be designed to remove or
recover vapor (see Section 4). Additionally, nitrogen containing
2 to 6 vol% oxygen should be used (see Section 8.2.4).
The location of tank car loading and unloading should be
distant from general activity, ignition sources and traffic. The
ground should be sloped toward a containment area to permit
recovery or disposal of any spills.
An automatic deluge sprinkler system should protect the
loading facility and rail tank car. A fire-water monitor nozzle
should be located within 40 feet of the tank car and should have
an unobstructed path to the target. Dry-powder or carbon
dioxide fire extinguishers should also be present.
Product Safety Bulletin 37
Product Storage
8.4 Workplace Location
Processing operations using styrene monomer should be located
and operated to minimize the potential risk of fire and explosion
and any possible consequence. The minimum distance of a
processing vessel to any adjoining property or building is based
on the stability of the chemical (see NFPA 30). These distance
requirements do not apply where a vessel is located in a building
and the exterior blank wall facing the vessel is more than 25 feet
away and has a two-hour fire rating and is explosion-resistant.
When a blank wall with a four-hour or greater fire resistance
rating is provided, there are no distance requirements. In the
case of styrene monomer, the wall must be explosion-resistant.
According to NFPA 30, processing equipment, such as
pumps, heaters and filters, should be kept at least 25 feet from
the property line or should be separated by a wall that has a
two-hour fire rating and is explosion-resistant. The operating
facility should be accessible from at least one side for
firefighting. For appropriate fire extinguisher types, refer to
Section 5.3.
Facilities storing or using styrene monomer should use
either a gravity or continuous mechanical-exhaust ventilation
system. If styrene monomer is dispensed within the room,
mechanical ventilation is required.
Dispensing of styrene monomer in the warehouse is not
recommended unless the dispensing area is suitably separated
from the other combustible or styrene monomer storage area.
38 Product Safety Bulletin
9. TRANSFER OPERATIONS
Styrene monomer should be transferred and handled according
to written operating procedures developed for the specific
facility. This section includes guidelines used by Lyondell
Chemical Company in its handling of styrene monomer.
Operating procedures should address the hazards associated
with this material (see Section 6), the selection of personal
protective clothing and equipment (see Section 3) and fireprevention methods (see Section 5). Only workers trained in
proper operating procedures should handle styrene monomer.
Dedicated unloading lines are recommended for styrene
monomer service. All unloading lines should be purged with an
inert gas before and after use to prevent air from entering the
storage system or to prevent spilling of liquid styrene monomer.
9.1 Work Preparation
When unloading vessels or containers, workers should have the
following equipment and supplies available:
• Functional local eyewash stations and safety showers
• Non-sparking tools
• Unloading block valve
• Stainless steel double-braided accordion-type hose
• Grounding connectors
• Nitrogen supply with pressure regulator and check valve
The consignee should determine that tank ullage (sufficient
capacity) is available to accept the shipment. Ensure that all
high-level warning devices are activated and functioning. Verify
that the material is styrene monomer by confirming that the
identification number is UN 2055 and by review of the
shipping documents and delivery schedule.
In certain circumstances and conditions, a “second” person
should verify proper valve positioning to confirm that the piping
is routed to the correct receiving tank. This may be advisable in
multi-tank bulk storage tank farms that have complicated piping
runs and contain other incompatible strong acids, bases or
oxidizers (see Sections 1.4 and 1.5).
Visually inspect containers for structural damage or
tampering in transit. Wet spots may be an indication of leaks.
Look for evidence of discharge from pressure relief valves.
Styrene monomer is supplied with an inhibitor to prevent
self-polymerization. Inhibitor depletion can occur during
extended transportation delays and exposure to high
temperatures. If product is received at high temperature or
pressure, a self-polymerization reaction may be occurring.
For more information on polymerization hazards, see
Section 1.6.
9.2 Tank Cars DOT 111A
Lyondell Chemical Company ships styrene monomer in DOT
111A tank cars (see Figure 9.1). Refer to 49 CFR 174 Subparts
C and G (see Appendix 4 for citations) for DOT unloading
regulations. The following procedures are comparable to those
used by Lyondell Chemical Company for unloading tanks cars
and can be used as a basis for site-specific procedures. A
suggested unloading checklist is provided in Figure 9.2.
9.2.1 Unloading Procedures
The unloading procedures for rail/tank cars are as follows:
1. Gather all necessary equipment. For tank car unloading, also
include:
• wheel chocks
• DOT-approved “STOP” signs
• derailer
2. Position the tank car correctly with respect to the unloading
station, then set its brake and chock one wheel on both sides.
3. Place DOT-approved, blue rectangular “STOP” signs at
both ends of the car between rails. Place an additional sign
at the rail siding switch.
4. Place a derailer on the rail siding between the car and the
siding switch. Lock derailer, if possible.
5. Be sure that the receiving tank’s ullage (available space) is
sufficient to receive the full load with room to spare after the
transfer is complete.
6. Identify all pipelines so proper valve alignment can be made.
7. Connect ground cable to car and check for continuity.
8. Remove and read the Lyondell Chemical Company label
attached to the car’s outlet valve. Make sure that it identifies
the car’s contents as styrene monomer. Also, remove the
one-eighth inch wire cable seal and verify the seal number
with the paperwork.
9. Determine that the unloading station’s spill collection sump
drain is closed and that the sump is substantially free of
accumulated liquid.
10.A sample can be taken, if needed, by using the three-fourths
inch sample valve at the top of the car.
11.Some tank cars may contain equipment for optional
nitrogen padding during off-loading. Tank car should be
unloaded with air only if the product temperature is below
the lower flammable limit (see Figure 5.1). If product
temperature is above lower flammable limit, unload under
nitrogen. Connect the nitrogen or dry air line to the one
inch threaded air line valve at the top of the car and open
the valve. The recommended psig is 20-30 for unloading if
not using a pump. If using a pump, you must feed nitrogen
or air in at a rate that will displace the liquid as the car is
being unloaded to prevent the tank from implosion.
Product Safety Bulletin 39
Transfer Operations
12.Attach flexible unloading hose to the car’s bottom outlet
valve after ensuring that all parts including gaskets and
O-rings are in good condition.
21.Close tank’s internal and external bottom outlet valves.
13.Set valves in fixed piping to begin transfer.
23.Close and secure manway latch.
22.Disconnect unloading hose, taking precautions to catch
residual styrene monomer for proper disposal.
14.Open car’s external (lower) bottom valve.
9.2.2 Release of Empty Car
15.Open car’s internal bottom valve. Check carefully for
leakage. If any is noted, take remedial action.
16.Start transfer pump.
The following steps complete the process of unloading tank cars:
1. Disconnect the ground cable.
17.Immediately make a visual check for leaks, especially at
places where seals and O-rings are present; shut down
immediately and take remedial action if leaks are observed.
2. Remove the wheel chocks, derailer, blue flag and caution
signs. Leave the car brakes engaged for railroad crew
to release.
18.Check that receiving tank’s level is rising at the expected rate
for the transfer system.
3. Make sure placards are affixed for return trip.
4. If there were any mechanical problems with the tank car,
advise Lyondell Chemical Company Customer Service
at (888) 777-0232.
19.Monitor the transfer. When the tank car is empty, close
pump discharge valve and immediately shut off pump.
20.Close valves connecting transfer line and pump to
receiving tank.
Figure 9.1 Typical Tank Car 111A-100W Configuration*
11
ATM
14
FROM SHUTDOWN INTERLOCKS
10
12
10
10
5
15
NITROGEN SUPPLY
17
10
10
10
16
13 10
TO
STORAGE (Figure 8-1)
18
TO 4
6
19
M
10
9
8
TO 7
13
16
5
STYRENE MONOMER
STABILIZED
21
3
1
7
4
39
2055
2
20
22
TO PUMP
23
1. WHEEL CHOCKS (BOTH SIDES OF WHEEL)
9. DRY DISCONNECT & FLEX. HOSE
3. HAZARD INDICATION PLACARD
10. ISOLATING VALVE
2. LABEL (FLAMMABLE LIQUID)
4. DRY DISCONNECT & FLEX. HOSE
ASSEMBLY (FOR BOTTOM UNLOADING)
5. SAFETY VALVE
6. MANWAY
7. VAPOR RETURN/AIR/NITROGEN CONNECTION
8. FLEX. HOSE ASSEMBLY
ASSEMBLY (FOR TOP UNLOADING)
16. APPROVED GROUND
17. STRAINER
18. PUMP
11. PRESSURE GAUGE
19. PRESSURE GAUGE W/DIAPHRAGM SEAL
13. CHECK VALVE
21. HAND BRAKE WHEEL
15. PRESSURE CONTROL VALVE
23. APPROVED GROUND CLAMP
12. NITROGEN HIGH POINT PURGE
14. PRESSURE SAFETY VALVE
20. HANDRAIL
22. DERAILER
*This figure illustrates a typical configuration and is not intended to be used as a design specification.
Qualified professionals must exercise engineering judgment to establish site specifications that meet the applicable requirements.
40 Product Safety Bulletin
Transfer Operations
Figure 9.2 Styrene Monomer Unloading Checklist – DOT 111A
Tank Car Number:
Date:
Operator:
Time:
AM/PM
Prior to Unloading Tank Car
Yes
No
Wheels chocked and hand brakes engaged .................................................................N
N
Blue flag and derailer in place ........................................................................................N
N
Metal caution signs located in front of and behind tank car ..........................................N
N
Storage tank capacity and tank car liquid level determined before filling......................N
N
Proper piping alignment made and checked .................................................................N
N
Product hose and fittings visually inspected prior to use ...............................................N
N
Eyebath and safety shower flushed and ready...............................................................N
N
Ground cable to car connected and checked for continuity ..........................................N
N
N2 hose hooked up to vapor valve ................................................................................. N
N
Transfer started and system visually checked for leaks .................................................N
N
Qualified operator in attendance during transfer............................................................N
N
After Unloading Tank Car
Yes
No
When tank car is empty, shut down the pump................................................................N
N
Unloading line valve closed to the storage tank .............................................................N
N
Tank car liquid unloading valve closed ..........................................................................N
N
N2 valve closed .............................................................................................................. N
N
Transfer line disconnected and residual liquid collected ...............................................N
N
Manway cover secured...................................................................................................N
N
Ground cable disconnected ...........................................................................................N
N
Are placards affixed and in good condition?..................................................................N
N
Blue flag and derailer device removed...........................................................................N
N
Wheel chocks removed...................................................................................................N
N
Car brake left engaged for railway crew.........................................................................N
N
Advise Lyondell Chemical Company of any mechanical problems at (888) 777-0232.
Product Safety Bulletin 41
Transfer Operations
9.3 Tank Cars DOT 105J
Lyondell Chemical Company also ships styrene monomer in
DOT 105J tank cars (see Figure 9.3). These tank cars are top
unloaded by pressure or pumping. Refer to 49 CFR 174 for
DOT unloading regulations.
The following procedures are comparable to those used by
Lyondell Chemical Company for unloading tanks cars and can
be used as a basis for site-specific procedures. A suggested
unloading checklist is provided in Figure 9.4.
9.3.1 Unloading Procedures
The unloading procedures for tank cars are as follows:
1. Gather all necessary equipment. For tank car unloading, also
include:
• wheel chocks
• DOT-approved “STOP” sign
• derailer
2. Position the tank car correctly with respect to the unloading
station, then set its brake and chock one wheel on both
sides.
3. Place DOT-approved, blue rectangular “STOP” signs at
both ends of the car between rails. Place an additional sign
at the rail-siding switch.
4. Place a derailer on the rail siding between the car and the
siding switch.
5. Connect ground cable to car and check for continuity.
6. Remove the one-eighth inch wire cable seal and verify the
seal number with the paperwork.
7. Remove the housing cover pin and lift pressure dome cover.
This will expose all valves and fittings which are required for
unloading and sampling (see Figure 9.5).
8. Inspect for leakage around valves and fittings in the pressure
dome area by pouring soapy water on the connections only
and checking for bubbles. If leaks are detected, tighten
fittings and recheck.
Figure 9.3 Typical Tank Car 105-J Configuration*
STYRENE MONOMER
STABILIZED
WHEEL CHOCKS (Both Sides of Wheel)
*This figure illustrates a typical configuration and is not intended to be used as a design specification.
Qualified professionals must exercise engineering judgment to establish site specifications that meet the applicable requirements.
42 Product Safety Bulletin
Transfer Operations
Figure 9.4 Styrene Monomer Unloading Checklist – DOT 105J
Tank Car Number:
Date:
Operator:
Time:
AM/PM
Prior to Unloading Tank Car
Yes
No
Wheels chocked and hand brakes engaged .................................................................N
N
Blue flag and derailer in place ........................................................................................N
N
Metal caution signs located in front of and behind tank car ..........................................N
N
Eyebath and safety shower flushed and ready...............................................................N
N
Ground cable to car connected and checked for continuity ..........................................N
N
Pressure dome inspected for leakage around valves and fittings..................................N
N
Bill of lading checked and sample verified.....................................................................N
N
Cerificate of analysis and placards checked..................................................................N
N
Storage tank capacity and tank car liquid level determined before filling......................N
N
Load and vent-back lines connected, purged and tested for leaks...............................N
N
Proper piping alignment made and checked .................................................................N
N
Open transfer lines and monitor liquid level ...................................................................N
N
Qualified operator in attendance during transfer............................................................N
N
After Unloading Tank Car
Yes
No
When tank car is empty, shut down the pump................................................................N
N
Transfer line blown clear of styrene monomer ................................................................N
N
Unloading line valve closed to the storage tank and the storage tank vent ...................N
N
Tank car vapor valve and liquid unloading valve closed................................................N
N
Transfer line vented of pressure ....................................................................................N
N
Transfer, nitrogen and storage tank vent lines disconnected ........................................ N
N
Test for leakage and secure dome cover .......................................................................N
N
Ground cable disconnected ...........................................................................................N
N
Are placards affixed and in good condition?..................................................................N
N
Blue flag, metal caution signs and derailer device removed..........................................N
N
Wheel chocks removed...................................................................................................N
N
Car brake left engaged for railroad crew........................................................................N
N
Advise Lyondell Chemical Company of any mechanical problems at (888) 777-0232.
Product Safety Bulletin 43
Transfer Operations
Figure 9.5 Typical Tank Car Dome Configuration*
*This figure illustrates a typical configuration and is not intended to be used as a design specification.
Qualified professionals must exercise engineering judgment to establish site specifications that meet the applicable requirements.
44 Product Safety Bulletin
Transfer Operations
9. If a sample from the tank car is required to confirm its
contents, the following procedure may be used: Sample tank
car through the sample line, which is located in the pressure
dome area. Fill the sample bottle leaving approximately
20 percent vapor space to allow for expansion. If closed
sampling system is not employed, proper personal protective
equipment should be used.
14.Open liquid unloading valve and allow styrene monomer to
fill the pump by opening the liquid line block valves. These
valves must be opened slowly to avoid activating the excess
flow valve. Start pump and begin pumping styrene
monomer to the storage tank. A positive pressure should be
maintained on the tank car to keep the pump from pulling a
vacuum on the car. Monitor this closely.
10.Determine the receiving tank ullage (available space) and the
liquid level in the tank car before transfer.
15.Check that the receiving tank’s level is rising at the expected
rate for the transfer system.
11.Attach nitrogen or vapor return line to the vapor valve.
16.Monitor the transfer. When the tank car is empty,
immediately shut off pump.
12.Attach flexible hose to the liquid unloading (eduction) valve.
13. Open vapor valve. If product will be unloaded under
nitrogen pressure, open vapor valve and use a regulator to
adjust the nitrogen pressure to equalize that of the tank car.
This will force liquid styrene monomer into unloading hose.
Nitrogen should be supplied in nominal pressures to
equalize the tank and ensure the pressure supply is
compatible with unloading system.
17.Clear the transfer line. Close the unloading line valve to the
storage tank and the storage tank vent. Close the tank car
vapor valve and the tank car liquid unloading valve. Vent
transfer line of pressure. Disconnect transfer, nitrogen and
storage tank vent lines.
18.Test for leakage by pouring soapy water over the valves. If
bubbles are present, retighten all valves and retest. If leaks
are still detected, contact Lyondell Chemical Company
Customer Service before shipping.
Figure 9.6 Typical Tank Truck Configuration*
5
6
7
8
9
TO PART NO. 7
19
DOT 407
DOT 412
STYRENE MONOMER
STABILIZED
ATM
17
12
4
3
13
M
1
10
To Part 11
2
2
14
18
15
11
14
AIR SUPPLY
OR VAPOR
BALANCE LINE
21
20
CHEMTREC 800/424-9300
17
14
16
1. REAR END PROTECTION
9. VACUUM BEAKER
17. CHECK VALVE
2. WHEEL CHOCKS (BOTH SIDES OF WHEEL)
10. OUTLET VALVE
18. PRESSURE GAUGE
3. CHEMTREC EMERGENCY NUMBER (800) 424-9300
11. FLEX. HOSE ASSEMBLY
19. FLEX. HOSE ASSEMBLY
4. DOT PLACARD (Figure 11.2) (ALL 4 SIDES)
12. GAUGING DEVICE
20. PRESSURE RELIEF VALVE
5. MANHOLE ASSY. & OVERTURN PROTECTION
13. CERTIFICATION PLATE
21. PRESSURE CONTROL VALVE
6. CUSTOMER VENT
14. GROUND WIRE
22. DOT CLASSIFICATION NUMBER
7. AIR INLET ASSEMBLY
15. STRAINER
8. PRESSURE VENT
16. PUMP
TO STORAGE
(Figure 8-1)
*This figure illustrates a typical configuration and is not intended to be used as a design specification.
Qualified professionals must exercise engineering judgment to establish site specifications that meet the applicable requirements.
Product Safety Bulletin 45
Transfer Operations
9.3.2 Release of Empty Car
The following steps complete the process of unloading tank cars:
1. Ensure that all valves are closed, and caps/plugs are in place
and are tightened.
2. Disconnect the ground cable.
3. Remove the wheel chocks, derailer, blue flag and caution
signs. Leave the car brakes engaged for railroad crew
to release.
4. Make sure placards are affixed and in good condition.
5. If there were any mechanical problems with the tank car,
advise Lyondell Chemical Company Customer Service.
9.4 Tank Trucks
Lyondell Chemical Company ships styrene monomer in
DOT 407 stainless steel tank trucks with approximate capacity
of 5,500 to 6,500 gallons. DOT 412 tank trucks are also
acceptable. They are normally bottom unloaded by gravity or
pumped through a valve located at the bottom of the truck
(see Figure 9.6). Refer to 49 CFR 177 for information on
unloading regulations. The following procedures are comparable
to those used by Lyondell Chemical Company for unloading
tank trucks and can be used as a basis for developing site-specific
procedures for unloading styrene monomer. A suggested
unloading checklist is provided in Figure 9.7.
9.4.1 Unloading Procedures
The unloading procedures for tank trucks are as follows:
1. Gather all necessary equipment. For tank truck unloading,
also include:
• road barriers
• wheel chocks
2. Instruct driver to position tank truck for unloading at
designated station, then set brakes, shut off engine and leave
cab. The driver should remain in a designated area.
3. Safeguard truck from nearby traffic by putting up road
barriers or warning lights. 4. Chock both sides of one tank truck wheel. 5. Attach ground connectors and ensure continuity to ground.
6. Remove and read the label attached to the tank truck’s outlet
valve to confirm that its contents are styrene monomer.
7. Visually inspect hoses and fittings prior to use. 8. Determine that the receiving storage tank has sufficient
capacity to hold the entire contents of the tank truck.
9. Identify all pipelines so that proper valve alignment can
be made. 10.Determine that the unloading station’s spill-collection sump
drain is closed and substantially free of accumulated liquid.
46 Product Safety Bulletin
11.Trucks are equipped for nitrogen unloading. Attach N2 line
and open valve. Tank cars should be unloaded with air only
if the product temperature is below the lower flammable
limit. If product temperature is above lower flammable
limit, unload under nitrogen.
12.Connect a flexible unloading hose to bottom discharge
valve connector. 13.Set valves in fixed piping to begin the transfer. 14.Open tank truck’s external (lower) outlet valve. 15.Open tank truck’s internal bottom valve. Check carefully for
leakage. If any is noted, take remedial action. 16.Start transfer pump. 17.Immediately make a visual check for leaks, especially at
places where seals and O-rings are present. If leaks are
observed, shut down immediately and take remedial action.
18.Check that the receiving tank’s level is rising at the expected
rate for the transfer system. 19.Monitor the transfer. When the tank truck is empty, close
pump-discharge valve and immediately shut off pump.
20.Close valves connecting transfer line and pump to
receiving tank. 21.Close the trailer’s internal and external bottom outlet valves.
22. Disconnect unloading hose, taking precautions to catch
residual styrene monomer for proper disposal. Store hose in
a protected location.
23.Close and secure the manway cover.
24.Pad with N2.
9.4.2 Release of Empty Truck
The following steps complete the process of unloading tank
trucks:
1. Ensure that all valves are closed, and caps/plugs are in place
and are tightened.
2. Disconnect the ground cable. Remove the wheel chocks and
traffic-control devices.
3. Ensure that tank truck placards for the return trip meet
DOT requirements. Ensure truck has been resealed.
4. Release the vehicle to the driver.
5. If there were any mechanical problems with the tank truck,
advise Lyondell Chemical Company Customer Service.
Transfer Operations
Figure 9.7 Styrene Monomer Unloading Checklist – DOT 407
Tank Car Number:
Date:
Operator:
Time:
AM/PM
Prior to Unloading Tank Truck
Yes
No
Trailer safeguarded with road barriers/warning lights ....................................................N
N
Wheels chocked and parking brakes engaged..............................................................N
N
Ground cable to truck connected and checked for continuity .......................................N
N
Storage tank capacity checked ......................................................................................N
N
Proper piping alignment made and checked .................................................................N
N
Product hose and fittings visually inspected prior to use ...............................................N
N
Eyebath and safety shower flushed and ready...............................................................N
N
N2 hooked up to vapor connection ................................................................................ N
N
Transfer started and system visually checked for leaks .................................................N
N
Qualified operator in attendance during transfer............................................................N
N
After Unloading Tank Truck
Yes
No
When tank truck is empty, shut down the pump.............................................................N
N
Unloading line valve closed to the storage tank .............................................................N
N
Tank truck’s internal and external bottom outlet valves closed ......................................N
N
Transfer line disconnected and residual liquid collected ...............................................N
N
Manway cover secured...................................................................................................N
N
Ground cable disconnected ...........................................................................................N
N
Placards proper for shipment .........................................................................................N
N
Wheel chocks removed...................................................................................................N
N
Advise Lyondell Chemical Company of any mechanical problems at (888) 777-0232.
Product Safety Bulletin 47
Transfer Operations
9.5 ISO Tanks
Lyondell Chemical Company ships styrene momomer in
intermodal bulk transport tanks meeting IM 101 (T2 tank
container) specifications. These tanks contain up to 4,800
gallons of styrene monomer and are shipped at atmospheric
pressure. The unloading valve is located at the rear bottom end
of the tank (see Figure 9.8). International Organization for
Standardization (ISO) tank work preparation and unloading
procedures are essentially the same as those in this section.
Figure 9.8 Typical T2 Tank Configuration
ATM
24
16
17
14
15
AIR SUPPLY
OR VAPOR BALANCE LINE
1
13
10
9
(2)
11
STYRENE MONOMER
STABILIZED
12
6
IM-101
23
5
2
FROM SHUTDOWN INTERLOCKS
25
20
27
7
CHEMTREC
(800) 424-9300
22
3
18
1. TANK FRAME
2. TANK SHELL IN STAINLESS STEEL
WITH INSULATION AND ALUMINUM
CLADDING PROTECTION
3. MALE BOTTOM DISCHARGE
4. DATA PLATE
5. LADDER
6. WALKWAY
7. STEAM HEATING
(NOT USED FOR STYRENE SERVICE)
8. THERMOMETER
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
SAFETY RELIEF VALVES (2) W/TANK
MANHOLE
AIR INLET
PROVISION FOR FILLING/DRAIN SYSTEM
BALL VALVE
FLEX. HOSE ASSEMBLY
CHECK VALVE
PRESSURE RELIEF VALVE
PRESSURE CONTROL VALVE
FILTER
21
19.
20.
21.
22.
23.
24.
25.
21
PUMP
PRESSURE GAUGE W/DIAPHRAGM SEAL
GROUND WIRE
FLEXIBLE HOSE ASSEMBLY
DOT CLASSIFICATION NO.
PRESSURE GAUGE
DOT PLACARD (Figure 11.2)
ALL 4 SIDES
26. CHEMTREC EMERGENCY NUMBER
(800) 424-9300
27. CARRIER’S NAME
CONTAINER OWNER/LESSOR’S NAME
CERTIFICATION DECALS
*This figure illustrates a typical configuration and is not intended to be used as a design specification.
Qualified professionals must exercise engineering judgment to establish site specifications that meet the applicable requirements.
48 Product Safety Bulletin
15
19
4
21
TO
STORAGE
See Figure 8-1
M
8
Transfer Operations
9.6 Marine Transport
A customer considering receipt of styrene monomer by water
for the first time should contact Lyondell Chemical Company
Customer Service for specific requirements.
Styrene monomer handling in marine transport is similar to
that required for other flammable liquid hydrocarbons.
However, a number of areas may be different and should be
evaluated before handling styrene monomer. These areas are:
1. Materials Compatibility – As discussed in Section 4,
materials requirements for styrene monomer should be
reviewed. Specifically, check compatibility of loading hoses
and tank and compartment liners or coatings.
2. Water Solubility – Styrene monomer is minimally soluble in
and somewhat lighter than water. Contact with water should
be avoided to maintain product quality. Also, any water
contaminated with styrene monomer should be evaluated
for waste classification (Section 7) and proper disposal.
3. Fire Foams – As discussed in Section 5, fire foams should
be evaluated to determine if alcohol resistant foams
are required.
4. Exposure – Any vented marine transfer operations should be
monitored to insure that vapor exposure is below the limits
discussed in Section 3. Exposure to high levels of styrene
monomer can result in eye, skin and respiratory irritation
and anesthetic-like effects (see Section 2).
Although styrene monomer has low atmospheric reactivity,
vapor recovery during marine loading operations may be
utilized, particularly in ozone-containment areas.
In the event that vapor recovery is utilized, Coast Guard
regulations require that the Maximum Experimental Safe Gap
(MESG) be evaluated to determine proper fire protection
equipment. The MESG for styrene monomer is .95 mm.
All barges to be loaded at Lyondell Chemical Company’s
Houston facility must be Coast Guard certified. Certification
will require the installation of a vapor recovery system.
In the case of a marine spill, styrene monomer should form
a slick which will slowly volatilize. Because of styrene monomer’s
low water solubility, little of the spilled styrene monomer will
dissolve into the water. The amount that dissolves will depend
on a number of factors including air and water temperatures
and turbulence. General spill handling guidelines are given in
Section 7.
Independent inspectors or surveyors take quality and
quantity measurements to ensure that styrene monomer is
loaded only into uncontaminated tanks. Tanks or compartments
should be in dedicated service for styrene monomer. Where
tanks or compartments are not in dedicated service, a cleaning
certificate along with a list of the last three cargos will be
required prior to loading. In addition, all tanks and
compartments receive an additional check at the one foot fill
level to insure product quality. Lyondell Chemical Company
has detailed guidelines available for inspectors.
Styrene monomer is normally loaded at a temperature less
than 21°C (70°F), with a TBC inhibitor content of between
10-15 ppm and a dissolved oxygen content of approximately
20 ppm. For short duration trips (approximately 10 days),
no additional precautions are usually needed to prevent
polymerization. If extended delays are expected or incurred,
daily product temperature checks should be conducted. An
increase in product temperature may be an indication of
polymerization. To reduce and control polymerization,
additional TBC can be added. For extended trips, lower
product temperature and higher TBC content can be arranged.
Chemical container ships used for long hauls may require
refrigeration of styrene monomer.
Daily temperature checks may be required.
4-tert-Butylcatechol inhibitor, in solution, should be available
for addition in case of polymerization. Styrene monomer
should not be stored adjacent to tanks or compartments that
are heated. Shifting of the styrene monomer to other tanks or
compartments should be avoided. Styrene monomer quality
and reactivity can be adversely affected by low levels of any
contaminant present.
As with other handling operations, the unloading of barges
or ships that contain hazardous materials such as styrene
monomer must only be carried out by fully trained personnel
equipped with all necessary information, PPE and suitable
equipment, following correct operating procedures.
In the event of any problems that may affect product, or any
indications of polymerization, contact Lyondell Chemical
Company Customer Service immediately.
Product Safety Bulletin 49
10. TANK CLEANING AND EQUIPMENT REPAIR
10.1 Work Preparation
Proper preparation for cleaning or maintaining styrene
monomer storage vessels and equipment is necessary to prevent
fire or harm to workers or the environment. Only fully trained
and properly equipped workers should clean or repair styrene
monomer tanks and equipment.
A hazardous work permit system should be established
before any maintenance or inspection activities involving hot
work, line breaking or confined-space entry are performed. A
permit should identify all job-related hazards and include a
work plan to address them. Facilities should use engineering
controls and appropriate personal protective equipment.
Before opening, tanks and equipment that contained styrene
monomer should be emptied of all liquid by draining at low
points. Tanks and equipment should then be purged with an
inert gas, then air, to a vapor management system, or they
should be flushed with water.
Eyewash and safety showers should be located near the work
area. Appropriate fire extinguishing equipment should be
present (see Section 5.3).
10.2 Control of Hazardous Energy
A facility’s procedures for controlling hazardous energy sources
should comply with the requirements of 29 CFR 1910.147
(see Appendix 4 for citations). These procedures should be used
to protect workers in areas where styrene monomer vessels or
equipment are cleaned, maintained or entered. After styrene
monomer has been purged, positive measures should be taken
to ensure that all potential sources of styrene monomer or
hazardous energy are physically tagged or locked out and
affected persons notified. Personal protective equipment
should be worn by workers who might be exposed to styrene
monomer residue.
10.3 Confined Space Entry
The OSHA standard (29 CFR 1910.146) establishes
requirements for entry into confined spaces. An OSHA confined
space is defined as a work zone large enough and so configured
to permit entry and work, has limited openings for entry or
exit and is not designed for continuous human occupancy.
A confined space may present one or more of the following
characteristics: a toxic, oxygen-deficient, flammable and/or
explosive atmosphere, an engulfment hazard and sidewalls that
could trap a worker.
Tanks and other process equipment that require worker
entry may be considered confined spaces.
Permit Required Confined Space (PRCS) program
requirements include:
1. Written program
2. Identify and classify spaces
3. Establish hazard control measures
• Prevent unauthorized entry
• Establish acceptable conditions
• Isolation
• Ventilation
• Coordinate entry by multiple workers
• Periodic re-evaluation for change of conditions
4. Develop permit system
• Preparation
• Issuance
• Implementation
• Cancellation
• Returning space to service
5. Provide specialized equipment
• Atmospheric monitoring
• Ventilation
• PPE
• Lighting
• Communication
• Emergency
6. Designate key personnel
• Entrants
• Attendants
• Entry supervisor
• Qualified atmospheric tester
• Emergency response
7. Perform testing and monitoring
• Prior to entry and periodically during entry and work
8. Establish rescue and emergency procedures
9. Procedures for contractors – multi-employer work sites
10.Provide information and training
11.Conduct program review
Product Safety Bulletin 51
Tank Cleaning and Equipment Repair
Training is required for three categories of workers involved
in confined space work: those entering the confined space,
attendants or standby/safety persons and the person authorizing
the permit. Workers should not enter confined spaces where
the styrene monomer vapor concentrations exceed 10 percent of
its lower flammable limit of 1.1 percent by volume without a
proper permit. Respiratory protection should be worn whenever
the styrene monomer concentration exceeds the TLV of 50 ppm
or the oxygen concentration is less than 19.5 percent (see
Section 3). An employee entering a confined space should be
able to readily and continuously communicate with a standby
person trained to provide emergency rescue.
10.4 Equipment Cleanout
Cleaning styrene monomer equipment is a hazardous operation
and should be conducted by experienced and trained workers in
compliance with a written, approved procedure. A job safety
analysis (JSA) or hazards analysis should be used to identify
hazards and necessary protective measures. The emptying of
styrene monomer vessels or storage tanks presents a danger of
ignition, toxic vapors and environmental contamination.
Vessels, lines and equipment should be emptied from
low-point drains and repeatedly rinsed with water until the
styrene monomer concentration is less than 1 percent. Residual
styrene monomer can be removed by purging with inert gas
such as nitrogen. Acidic cleaning solutions should not be used
because their residues can cause polymerization. To protect
product quality vessels, lines and equipment should be clean and
dry before being placed into service initially or after repair.
Polymerized styrene monomer should be removed from interior
surfaces. Polymer usually forms around internal tank supports,
openings, valves, flanges and vents.
If a vessel is to be entered for cleaning, the guidelines for
control of hazardous energy and confined space entry in this
section should be followed.
52 Product Safety Bulletin
10.5 Maintenance and Inspection
Facilities should conduct preventive maintenance and inspection
of containers, hoses, pumps, fittings, fire protection equipment
and refrigeration units used for styrene monomer. An adequate
supply of spare parts for refrigeration units should be
maintained. Maintenance and inspection schedules should be
established that are appropriate for the device or equipment.
Inspectors should be trained how to identify abnormal
situations and conduct a proper inspection. A checklist or guide
should be used to conduct inspections, and all findings and
work carried out should be recorded.
Styrene monomer bulk storage tanks should be emptied and
visually inspected regularly, such as every two years. The
inspection frequency should be increased if polymer formation
occurs. Inspections should include lining, roof, vents, seals,
relief valves piping and tank openings.
Preventive maintenance schedules should be developed
for critical equipment such as fire fighting equipment,
combustible gas detectors, tank instruments and gauges, pumps,
safety-relief valves, isolating valves, gaskets and emissioncontrol equipment.
11. Transportation Regulatory Requirements
The Distribution Safety Program of Lyondell Chemical
Company has been implemented in accordance with the
company’s Operational Excellence Standards.
Not every authorized U.S. Department of Transportation
(DOT), International Maritime Organization (IMO),
International Civil Aviation Organization (ICAO) or
International Air Transport Association (IATA) packaging
is addressed in this chapter. Lyondell Chemical Company
has selected transport routes and modes, in concert with
packaging configurations, to develop and implement risk
reduction alternatives.
This bulletin is written is accordance with the Code of
Federal Regulation, Title 49 issued Jan. 29, 2003.
Federal regulations describe authorized procedures to
properly package, mark, label, placard and manifest shipments.
These procedures depend upon the quantity and type of
hazardous material and the method of transport of the
substance. If one plans to transport hazardous material
internationally by air, then the requirements of the IATA and
ICAO must be met. Shipment by water requires compliance
with the IMO regulations.
Lyondell Chemical Company recommends that those
offering hazardous materials for transport be trained in the
proper application of these regulations.
11.2 Marking, Labeling and Placarding
11.1 Classification
11.3 Packaging
Styrene monomer is listed in the Hazardous Materials Table (49
CFR 172-101). Therefore, it is classified as a hazardous material
for transportation purposes. The table gives the following
designation for styrene monomer:
• Proper shipping name – Styrene monomer, stabilized
• Hazard Class – 3
• Identification Number – UN 2055
• Packing Group – III
• Label Required – Flammable Liquid
Packaging exceptions are permitted. Limited quantity shipments
with inner packagings not exceeding 5.0 liters net capacity each,
are authorized (49 CFR 173 Subpart D).
Non-bulk packaging is explained in 49 CFR 173 Subpart E,
and bulk packaging is described in Subpart F.
In bulk packagings, liquids must be loaded so that the
outage is at least 1 percent of the total capacity of a cargo or
portable tank, or compartment thereof, or at least 1 percent of
the total capacity of the tank and dome for tank car and
multi-unit tank car tanks at the reference temperature of 46°C
(115°F) for uninsulated tanks and 41°C (105°F) for insulated
tanks. Hazardous materials may not be loaded into the dome of
a tank car. If the dome of the tank car does not provide
sufficient outage, vacant space must be left in the shell to
provide the required outage (49 CFR 173 Subpart B). The
outage for an IM portable tank may not be less than 2 percent
at a temperature of 50°C (122°F).
The maximum volume of styrene monomer in various
bulk packaging may be calculated for the referenced temperature
using Table 1.2, Styrene Monomer Density as a Function
of Temperature.
• Appendix A to HMT – RQ is 454 kg, 1000 lbs.
The following description is required on the bill of lading
for styrene monomer under DOT regulations (49 CFR 172
Subpart C):
• Styrene monomer, stabilized 3, UN 2055, PG III.
• RQ (454 kg, 1000 lbs.)
Identification numbers are required on each side and each
end if the packaging capacity is 1000 gallons or more; on
two opposing sides if the packaging capacity is greater than
119 gallons, but less than 1000 gallons. Markings for non-bulk
packaging (119 gallons or less) include the proper shipping
name, identification number preceded by UN or NA,
the technical name, if applicable, and the consignor’s name
and address.
Labels are required on non-bulk packages and must be
located on the same surface and near the marking.
Placards are required on each side and each end of
bulk packaging.
Requirements concerning marking, labeling, placarding and
the preparation of shipping papers vary somewhat depending on
the transport mode, packaging configuration and quantity of
hazardous material being transported.
Marking, labeling and placarding requirements are
explained in detail in 49 CFR 172 Subparts D, E and F,
respectively. Labels and placards applicable to flammable liquids
are required for styrene monomer (see Figures 11.1 and 11.2).
Bulk containers should remain placarded when emptied unless
the special requirements of Subpart F are met.
Product Safety Bulletin 53
Transportation Regulatory Requirements
Figure 11.1
Figure 11.2
11.3.1 Tank Cars
11.3.3 ISO Tanks
In accordance with 49 CFR 173, DOT 111A tank cars are
authorized to carry styrene monomer. Lyondell Chemical
Company prefers to ship styrene monomer by rail in tank cars
meeting DOT Specification 105J300W. Such cars are of mild
steel construction and have capacities of 26,000 gallons. These
are pressure cars with no bottom outlets. The DOT 105J300W
cars are preferred because their probability of consequential
product release is lower than the general purpose car.
Styrene monomer should be transported by rail only
if it is consigned to a party having a private track (49 CFR
171.8) or to a party using railroad siding facilities that are
equipped for piping styrene monomer from the tank car to
permanent storage.
Tank cars loaded with styrene monomer should be placarded
with “FLAMMABLE” placards according to 49 CFR 172
Subpart F (see Figure 11.2).
ISO tanks are a specific class of intermodal (IM) tanks designed
and constructed to permit their use interchangeably in two or
more modes of transport. Lyondell Chemical Company ships
styrene monomer in ISO tanks constructed of either steel or
stainless steel that meets IM-101 (T2 tank container)
specifications (1.5 bar minimum test pressure) and Chapter 13
of the International Maritime Dangerous Goods (IMDG) Code.
Such tanks must be at least 80 percent full during transport.
When ISO tanks are transported by road, they must be on dropchassis trailers only.
11.3.2 Tank Trucks
Lyondell Chemical Company ships styrene monomer in
DOT 407 stainless-steel tank trucks with capacities ranging
from 5,500 to 6,600 gallons. They are equipped for unloading
from bottom outlet valves. See 49 CFR 173 Subpart F for
special requirements concerning the pressure relief system and
bottom outlets.
Refer to 49 CFR 180 Subpart E for information on
requirements for testing and inspection of cargo tanks,
minimum qualification for inspectors and testers, tests and
inspection markings and reporting and records-retention
requirements. These regulations should be reviewed in detail to
establish inspection protocols for tank trucks used in the
transport of styrene monomer.
A suggested tank truck unloading procedure is
provided in Section 9.4.
54 Product Safety Bulletin
11.3.4 Canadian Transborder Highway Shipments
With the exception of retro reflective placarding, the origin
country’s hazardous material regulations govern. Reciprocal
agreements are found in the respective regulations. Retro
reflective placards are required in both directions. Intra
Canadian shipments are governed by Transport Dangerous
Goods regulations exclusively.
11.3.5 Marine Transportation
The transport of styrene monomer on cargo and passenger
vessels is permitted for on-deck and under-deck stowage. For
cargo vessels, the United States DOT specification and UN
Standard packaging is constructed of materials that will not
react dangerously with or be decomposed by the styrene
monomer (see Section 1.5).
The requirements for shipment of poisonous and flammable
liquids such as styrene monomer over water are defined in
49 CFR 176. Lyondell Chemical Company transports styrene
monomer in ISO tanks on container ships or barges.
Vessel/barge owners should comply with 46 CFR 153,
Code for the Construction and Equipment of Ships Carrying
Dangerous Chemicals in Bulk (BCH Code) and
Transportation Regulatory Requirements
Regulations for the Control of Pollution by Noxious Liquid
Substances in Bulk. These are Coast Guard and IMO
regulations governing vessel/barge operation and construction.
The application and maintenance of a nitrogen blanket for
styrene monomer in an ISO tank is detailed in 46 CFR
153.500. An independent inspector is employed for quality and
quantity measurements to ensure that the styrene monomer is
loaded in uncontaminated tanks (see Section 9.6).
11.3.6 Air Transportation
Styrene monomer may be transported domestically and
internationally by air in specific packagings and quantities
which comply with ICAO technical instructions. These
regulations have been generally incorporated in DOT
regulations (49 CFR 175) cited in this section. A package shall
not contain more than 220 liters on a cargo-only aircraft. Inner
packagings not over 5.0 liters net capacity each, packed in
strong outer packagings, are authorized by exception in limited
quantities. The entire package cannot exceed 66 pounds gross
weight (CFR Part 173, Subpart D). Applicable regulations
should be reviewed thoroughly prior to shipping styrene
monomer by air.
11.4 Transportation Emergencies
Lyondell Chemical Company markets its products in a
manner which takes into consideration the health and safety
of customers, transporters and the general public. However,
emergencies can occur in spite of best precautions. Lyondell
Chemical Company has made provisions to respond to
all emergencies.
All Lyondell Chemical Company Material Safety Data
Sheets (MSDS) include telephone numbers for CHEMical
TRansportion Emergency Center (CHEMTREC). The
CHEMTREC numbers are (800) 424-9300, and you can call
collect at (202) 483-7616. The number for Lyondell Serious
Chemical Distribution Incident Response System (SCDI) is
(800) 245-4532. These numbers are staffed 24 hours a day. If
the event of a transportation emergency, CHEMTREC should
be called first, with a follow-up call to SCDI.
SCDI was established to minimize the effects of any out-ofplant incidents by providing an efficient and responsible means
of emergency assistance. It covers incidents such as
transportation accidents (e.g., collisions, rollovers or
derailments), shipping container damage or leaks, difficulties at
customer facilities, leaks or spills in distribution terminals or toll
processors’ facilities and exposure under all circumstances.
When notification of an SCDI emergency is received at
Lyondell Chemical Company Channelview, Texas plant, the call
is immediately directed to a group of trained coordinators. The
coordinator who receives the emergency call will immediately
contact the person originally requesting assistance (according to
49 CFR 172 Subpart G) to confirm receipt of the notification,
obtain details and agree upon the course of action.
11.4.1 CANUTEC
If an emergency involving a Lyondell Chemical Company
product occurs in Canada, you may call CANadian Transport
Emergency Centre (CANUTEC) collect at (613) 996-6666.
CANUTEC is the national bilingual advisory service provided
by Transport Canada to assist emergency response personnel in
handling dangerous goods emergencies. CANUTEC should be
called first, with a follow-up call to SCDI.
11.4.2 SETIQ
If an emergency accident/incident occurs in Mexico, you
may elect to call SETIQ (in the Mexican Republic) at
(800) 002-1400; (Calls originating in Mexico City or in the
Metropolitan Area) (5) 559-1588; (Calls originating elsewhere)
(52-555) 559-1588.
11.4.3 Reporting Requirements
A transportation incident involving styrene monomer may
necessitate the notification of federal authorities. Refer to
49 CFR 171 for detailed response and reporting requirements.
11.4.4 Transport of Styrene Monomer Residue
If a discharge of styrene monomer occurs during transport, an
official of the federal, state or local government may require its
immediate removal to prevent further consequences, according
to DOT regulations (49 CFR). The removal may be made
without preparing a manifest. The EPA does not require the
freight carrier to have an EPA identification number (see EPA
regulations, 40 CFR) under such circumstances. If a hazardous
waste transporter removes the residue, EPA regulations require
that an EPA identification number be used.
Product Safety Bulletin 55
APPENDIX 1. CONVERSION FACTORS
Symbols for Abbreviations of Units
°R– Rankine temperature (°R = 9/5°Kelvin)
in– inch
ft– foot
yd– yard
mi– mile
gal– U.S. gallon
bbl– barrel
h– hour
Pa– Pascal
lb– pound (av)
oz– ounce (av)
lb-mol– pound mole
Btu– British thermal unit
hp– horsepower
m– meter
g– gram
To convert the numerical value of a property expressed in one of the units in the left-hand column of the following tables to the
numerical value of the same property expressed in one of the units in the top row of the same table, multiply the original value by the
factor in the block common to both units. The SI unit is listed first in each table. Factors with less than seven significant digits are
exact as written.
Units of Mass
1 kg
1g
1 metric ton
1 ton (US)
1 lb
1 oz
kg
1
1x10 –3
1000.
907.1847
0.45359237
0.02834952
g
1000.
1
1x10 6
9.071847x10 5
453.59237
28.34952
metric ton
1x10 –3
1x10 –6
1
0.9071847
4.5359237x10 –4
2.834952x10 –5
ton (US)
1.102311x10 –3
1.102311x10 –6
1.102311
1
0.0005
3.125x10 –5
lb
2.204623
2.204623x10 –3
2204.623
2000.
1
0.0625
oz
35.27396
0.03527396
35273.96
32000.
16.
1
(1 Liter = 1 dm 3)
Units of Volume
1m
1 dm 3
1 cm 3
1 yd 3
1 ft 3
1 in 3
1 gal
1 bbl
3
1 m3
1 dm 3
1 cm 3
1 yd 3
1 ft 3
1 in 3
1 gal
1 bbl
m3
1
1x10 –3
1x10 –6
0.7645549
0.02831685
1.638706x10 –5
3.785412x10 –3
0.1589873
in 3
6.102374x10 4
61.02374
0.06102374
46656.
1728
1
231.
9702.
dm 3
1000.
1
1x10 –3
764.5549
28.31685
0.01638706
3.785412
158.9873
gal
264.1721
0.2641721
2.641721x10 –4
201.9740
7.480519
4.329004x10 –3
0.02380952
42.
cm 3
1x10 6
1000.
1
7.645549x10 5
28.31685x10 3
16.38706
3785.412
1.589873x10 5
bbl
6.289812
6.289812x10 –3
6.289812x10 –6
4.808905
0.1781076
1.030715x10 –4
1
yd 3
1.307950
1.307950x10 –3
1.307950x10 –6
1
0.03703704
2.143347x10 –5
4.951132x10 –3
0.2079475
ft 3
35.31467
0.03531467
3.531467x10 –5
27
1
5.787037x10 –4
0.1336806
5.614558
(1 Liter = 1 dm 3)
Product Safety Bulletin 57
Appendix 1. Conversion Factors
Units of Density
1 kg m
1 g cm –3
1 lb ft –3
1 lb in –3
1 lb gal –1
–3
kg m –3
1
1000.
16.01847
27679.91
119.8264
g cm –3
0.001
1
0.01601847
27.67991
0.1198264
lb ft –3
0.06242795
62.42795
1
1728.
7.480519
lb in –3
3.612728x10 –5
0.03612728
5.7870370x10 –4
1
4.3290043x10 –3
lb gal –1
8.345403x10 –3
8.345403
0.1336806
231.
1
(1 g dm –3= 1 kg m –3)
Units of Pressure
1 Pa
1 bar
1 dyne cm –2
1 kg(wt) cm –2
1 atm
1 torr
1 lb in –2
1 in Hg(60°F)
1 in H2O(60°F)
1 Pa
1 bar
1 dyne cm–2
1 kg(wt) cm–2
1 atm
1 torr
1 lb in–2
1 in Hg(60°F)
1 in H2O(60°F)
Pa
1
1x10 5
0.1
98066.5
101325.0
133.3224
6894.757
3376.85
248.835
torr
7.500617x10 –3
750.0617
7.500617x10 –4
735.5592
760.
1
51.71493
25.3285
1.86642
bar
1x10 –5
1
1x10 –6
0.980665
1.013250
1.333224x10 –3
0.06894757
0.0337685
2.48835x10 –3
lb in -2
1.450377x10 –4
14.50377
1.450377x10 –5
14.22334
14.69595
0.01933678
1
0.489757
0.0360895
dyne cm –2
10.
1 x10 6
1
980665.
1013250.
1333.224
68947.57
33768.5
2488.35
in Hg(60°F)
2.961340x10 –4
29.61340
2.961340x10 –5
29.0408
30.0058
0.0394812
2.04183
1
0.0736885
kg(wt) cm –2
1.019716x10 –5
1.019716
1.019716x10 –6
1
1.033227
1.359510x10 –3
0.07030696
0.0344343
2.53741x10 –3
in H2O(60°F)
4.01872x10 –3
401.872
4.01872x10 –4
394.103
407.197
0.535786
27.7089
13.5706
1
atm
9.869233x10 –6
0.9869233
0.9869233x10 –8
0.9678411
1
1.315789x10 –3
0.06804596
0.0333269
2.45581x10 –3
Units of Dynamic Viscosity
1 Pa s
1 kgf s m –2
1 poise
1 cP
1 lbf s in –2
1 lbf s ft –2
Pa s
1
9.80665
0.1
0.001
6894.758
47.88026
kgf s m –2
0.1019716
1
0.01019716
1.019716x10 –4
703.0697
4.882428
poise
10
98.0665
1
0.01
68947.58
478.8026
cP
1000.
9806.65
100.
1
6894758.
47880.26
lbf s in –2
1.450377x10 –4
1.422334x10 –3
1.450377x10 –5
1.450377x10 –7
1
6.944444x10 –3
lbf s ft –2
0.02088543
0.2048161
2.085543x10 –3
2.088543x10 –5
144.
1
Units of Thermal Conductivity
1 W m –1 K –1
1 cal s –1 cm –1 K –1
1 cal hr –1cm –1K –1
1 Btu s –1 ft –1 °R –1
1 Btu hr –1 ft –1 °R –1
W m –1K –1
1
418.4
0.1162222
6230.646
1.730735
58 Product Safety Bulletin
cal s –1cm –1K –1
2.390057x10 –3
1
2.777778x10 –4
14.89160
4.136555x10 –3
cal hr –1cm –1K –1
8.604205
3600.
1
53609.77
14.89160
Btu s –1ft –1°R –1
1.604970x10 –4
0.06715194
1.865332x10 –5
1
2.777778x10 –4
Btu hr –1ft –1°R –1
0.5777892
241.7471
0.06715197
3600.
1
APPENDIX 2. WORLDWIDE OCCUPATIONAL EXPOSURE LIMITS
Styrene Monomer
Country
ACGIH TLV3
Belgium
British Columbia – Canada
China
Finland
Germany
Japan
Mexico
Netherlands
Spain
Sweden
United Kingdom
USA – NIOSH REL4
TWA81 (ppm)
STEL2 (ppm)
20
50
50
50
20
20
20
50
25
20
20
100
50
40
100
75
100
100
40
—
100
—
40
50
250
100
Reference: 2006 ACGIH® [American Conference of Governmental Industrial Hygienists]
TWA8 is the eight-hour Time Weighted Average.
STEL is the Short Term (15 minute) Exposure Limit.
3
TVL is the Threshold Value Limit.
4
NIOSH REL is the National Institute for Occupational Safety and Health Recommended Exposure Limit
1
2
Product Safety Bulletin 59
APPENDIX 3. NAMES AND ADDRESSES OF MANUFACTURERS
Combustible Gas Detectors
TLV Sniffer
Bacharach, Inc.
621 Hunt Valley Circle
New Kensington, PA 15068-7074
(724) 334-5000
Explosimeter
MSA
P.O. Box 426
Pittsburgh, Pennsylvania 15230
(800) MSA-2222
OVM Badge System
Colorimetric Detector Tubes
Infrared Spectrophotometers
MIRAN 1B2
MIRAN 1BX
MIRAN 101
MIRAN 103
MIRAN 1B
MIRAN 1A
Invensys/Foxboro
33 Commercial Street
Foxboro, MA 02035
(866) 746-6477 (US & Canada)
(508) 549-2424 (International)
Styrene (Nos. 124 or 124L)
Sensidyne
16333 Bay Vista Drive
Clearwater, FL 34620
(727) 530-3602
Styrene
Draeger Safety Inc.
101 Technology Drive
Pittsburgh, PA 15275-1057
(800) 858-1737
Chemical Protective Clothing
Ansell Edmont Industrial
200 Schultz Dr.
Red Bank, NJ 07701
(800) 800-0444
Flame Ionization Detectors
Century OVA 128
Century OVA 108
Invensys/Foxboro
33 Commercial Street
Foxboro, MA 02035
(866) 746-6477 (US & Canada)
(508) 549-2424 (International)
Best Manufacturing Company
579 Edison Street
Menlo, GA 30731
(800) 241-0323
Photoionization Detectors
Photovac’s TIP
Photovac Inc.
176 Second Avenue
Waltham, MA 02451
(781) 290-0777
HNU Model PI01
HNU Process Analyzers
25 Walpole Park South Drive
Walpole, MA 02081
(800) 743-6826 (US & Canada)
(508) 660-5001 (International)
TraceAir®
Morphix Technologies
2557 Production Road
Virginia Beach, VA 23454
(800) 808-2234
Comasec Safety Inc.
P.O. Box 1219
8 Niblick Road
Enfield, CT 06082
(800) 333-0219
Chem-Tex Corp.
P.O. Box 5878
550 West Ingham Ave.
Trenton, NJ 08638
(609) 392-6770
(800) 875-6770
TraceAir is a registered trademark of Morphix Technologies.
Product Safety Bulletin 61
APPENDIX 4. REFERENCES
STYRENE MONOMER
ACGIH
American Conference of Governmental Industrial Hygienists
6500 Glenway Avenue, Bldg. D-7
Cincinnati, OH 45211-4438
ACGIH; Threshold Limit Values and Biological Exposures
Indices
AIHA
American Industrial Hygiene Association
2700 Prosperity Avenue, Ste. 250
Fairfax, VA 22031
ANSI
American National Standards Institute
1819 L Street, NW
Washington, DC 20036
ANSI Z358.1; Emergency Eye Wash and Shower Equipment
ANSI Z88.2; American National Standard for Respiratory
Protection
ANSI Z87.1; Occupational and Eductional Personal Eye
and Face Protection Devices
API
American Petroleum Institute
1220 L Street, N.W.
Washington, DC 20005
API RP-520; Recommended Practice for the Design and
Installation of Pressure-Relieving System in Refineries
Part I – Design
ASME
American Society of Mechanical Engineers,
United Engineering Center
45 East 47th Street
New York, New York 10017
ASME Code, Section VIII, Division 1; Boiler and Pressure
Vessel Code
ASME/ANSI B31; American National Standard Code For
Pressure Piping
DOT
Department of Transportation
400 Seventh Street, S.W.
Washington, DC 20590
49 CFR 171; General Information, Regulations and Definitions
49 CFR Part 172; Hazardous Materials Table, Special
Provisions, Hazardous Materials Communication Requirements
and Emergency Response Requirements
49 CFR 173; Shippers – General Requirements for Shipments
and Packaging
49 CFR 174; Carriage by Rail
49 CFR 176; Carriage by Vessel
Carriage by Public Highway
49 CFR 178; Shipping Containers Specifications
49 CFR 179; Specifications for Tank Car
49 CFR 180; Qualification and Maintenance of Cargo Tanks
continues next page
API RP-520; Sizing, Selection and Installation of PressureRelieving Devices in Refineries Part II – Installation
API 601; Metallic Gaskets for Raised-Face Pipe Flanges
and Flanged Connections (Double-Jacketed Corrugated and
Spiral-Wound)
API 620; Recommended Rules for the Design and Construction
of Large Welded, Low-Pressure Storage Tanks
API 650; Welded Steel Tanks for Oil Storage
API RP-2000; Venting Atmospheric and Low-Pressure
Storage Tanks
API RP-2003; Protection Against Ignition Arising Out of
Static, Lightning, and Stray Currents
API RP-2028; Flame Arresters in Piping System
API RP-2210; Flame Arresters for Vents of Tanks Storing
Petroleum Product
API RP-2350; Protection for Petroleum Storage Tanks,
First Edition
Product Safety Bulletin 63
Appendix 4. References
EPA
IMO
United States Environmental Protection Agency
401 M Street, S.W.
Washington, DC 20460
40 CFR 260; Hazardous Waste Management System: General
International Maritime Organization
Albert Embankment
London SE,1 England
IMDG; International Maritime Dangerous Goods Codes
40 CFR 261; Identification and Listing of Hazardous Waste
40 CFR 262; Standards Applicable to Generators of Hazardous
Waste
40 CFR 263; Standards Applicable to Transporters of
Hazardous Waste
40 CFR 264; Standards for Owners and Operators of
Hazardous Waste Treatment, Storage and Disposal Facilities
40 CFR 265; Interim Status Standards for Owners and
Operators of Hazardous Waste Treatment, Storage and Disposal
Facilities
40 CFR 266; Standards for the Management of Specific
Hazardous Waste and Specific Types of Hazardous Waste
Management Facilities
40 CFR 267; Interim Standards for Owners and Operators of
New Hazardous Waste Treatment, Storage and Disposal Facilities
NFPA
National Fire Protection Association
Batterymarch Park
Quincy, Massachusetts 02269
NFPA 10; Portable Fire Extinguishers
NFPA 11;Foam Extinguishing Systems, Low Expansion and
Combined Agent
NFPA 30;Flammable and Combustible Liquids Code
NFPA 70;National Electrical Code
NFPA 77;Static Electricity
NFPA 704;Standard System for the Identification of the Fire
Hazards of Materials
NIOSH
40 CFR 270; EPA Administered Permit Programs: The
Hazardous Waste Permit Program
National Institute for Occupational Safety and Health
US Department of Health, Education and Welfare
4676 Columbia Parkway
Cincinnati, Ohio 45226
40 CFR 271; Requirements for Authorization of State
Hazardous Waste Programs
NTP
40 CFR 268; Land Disposal Restrictions
40 CFR 272; Approved State Hazardous Waste Management
Programs
40 CFR 372; Toxic Chemical Release Reporting: Community
Right-to-Know
IARC
International Agency for Research on Cancer
49 Sheridan Street
Albany, New York 12210
IATA
International Air Transport Association
1155 Mansfield Street
Montreal 113, P.Q., Canada
IATA; Dangerous Goods Regulations
ICAO
International Civil Aviation Organization
1000 Sherbrooke Street West
Suite 400
Montreal, Quebec, Canada H3A 2R2
ICAO; Technical Instructions for Safe Transport of Dangerous
Goods, By Air
64 Product Safety Bulletin
National Toxicology Program
P.O. Box 12233
Research Triangle Park, North Carolina 27709
OCCUPATIONAL HEALTH REFERENCES
(FOR SECTION 2)
K.M. Bodner, G.G. Bond, R.R. Cook. Review of Recent
Epidemiological Studies. Prepared for Styrene Information &
Research Center (SIRC), 1987.
N. Cherry. The Effects of Occupational Exposure to Styrene
on the Nervous System in Man. Prepared for SIRC.
J. Orr, R. Brillinger, I.C. Munroe and R.F. Willes. Review of
Styrene Pharmacokinetics and Carcinogenicity. Prepared for
SIRC, 1989.
The SIRC Review, vol. 1, No. 1. 1990.
Ibid. vol. 1, No. 2. 1990.
H.C. Spencer, D.D. Irish, E.M. Adams and V.K. Rowe. J.
Ind. Hyg. Toxicol. 24, 295, 1942.
USEPA Drinking Water Criteria Document, PB86-1180556,
1985.
M.A. Wolfe, V.K. Rowe, D.D. McCollister, R.C.
Hollingsworth, F. Oyen. Am. Med. Assoc. Arch. Ind. Health
14, 387, 1956.
(The SIRC documents and the EPA document contain
complete listings of all pertinent articles and have been used
extensively in preparing this Bulletin.)
Appendix 4. References
OSHA
UL
Occupational Safety and Health Administration
United States Department of Labor
200 Constitution Avenue, N.W.
Washington, DC 20210
29 CFR 1910.106; Flammable and Combustible Liquids
Underwriter’s Laboratories
333 Pfingston Road
Northbrook, IL 60062
UL 525; Flame Arresters for Use on Vents of Storage Tanks for
Petroleum Oil and Gasoline
29 CFR 1910.119; Process Safety Management of Highly
Hazardous Chemicals
29 CFR 1910.120; Hazardous Waste Operations and
Emergency Response (HazWOpER)
29 CFR 1910.134; Respiratory Protection
29 CFR 1910.146; Permit-Required Confined Space
29 CFR 1910.147; Sources of Standards
29 CFR 1910.151; Medical Services and First Aid
29 CFR 1910.156; Fire Brigades
29 CFR 1910.157; Portable Fire Extinguishers
29 CFR 1910.252; Welding, Cutting, and Brazing
UN
United Nations
First Avenue and 42nd Street
New York, NY 10017
Recommendations on the Transport of Dangerous Goods
US COAST GUARD
US Coast Guard, Headquarters
2100 Second Street, S.W.
Washington, DC 20093-0001
46 CFR 153; Ships Carrying Bulk Liquid, Liquefied Gas, or
Compressed Gas Hazardous Material
29 CFR 1910.1000; Air Contaminants
29 CFR 1910.1200; Hazard Communication
Product Safety Bulletin 65
APPENDIX 5. REGULATORY SUMMARY
Styrene Monomer
The following summary presents some of the federal, state and
international laws and enabling regulations that require review
prior to handling, storage or distribution of styrene (or styrene
monomer). This overview is not and should not be construed as
an all inclusive source of information. In addition, other
international, federal, state and local laws and regulations may
be applicable.
Federal
Clean Air Act
The Clean Air Act required the EPA to set national ambient air
quality standards for pollutants determined to be injurious
to health or welfare.
Styrene is listed as a potential human health hazard under
Section 111. Specific control technologies are defined for
such hazardous chemicals (40 CFR 60.489).
Amendments to the Clean Air Act enacted in 1990 required
the EPA to establish technology standards applicable to the
sources of listed pollutants.
Styrene is listed as a hazardous air pollutant in Section
112(b). As a result, facilities that manufacture styrene will be
subject to Maximum Achievable Control Technology
standards. This listing also may require additional emission
controls at facilities that use styrene as a solvent or reactant.
Hazardous Organic NESHAP (HON) Synthetic Organic
Chemicals (40 CFR 63. 100-106, Table 1).
Under a final rule effective 4/22/94, styrene is listed as a
“Group I” chemical. Existing sources of chemicals in Group I
must comply with equipment leak rules (40 CFR 63.160182) by 10/24/94.
Clean Water Act
The Clean Water Act was enacted to ensure the chemical,
physical and biological integrity of the nation’s waters by setting
national water standards for publicly-owned treatment works
and industry and by creating the National Pollutant Discharge
Elimination System (NPDES) permit program. The following
sections of the law may be of interest to the user of styrene:
Section 307 Priority Pollutants (40 CFR 401.15) – styrene is
not listed.
Comprehensive Environmental Response,
Compensation, & Liability Act (CERCLA)
CERCLA, more commonly known as “Superfund,” established
a list of more than 700 hazardous substances that, when released
in quantities equal to or exceeding a specified reportable
quantity (RQ), must be reported to the National Response
Center. Most CERCLA hazardous substances are subject not
only to CERCLA regulations but also to the Superfund
Amendments & Reauthorization Act (SARA) Title III, Section
304, emergency notification requirements (see below).
Styrene is a listed hazardous substance. The RQ is 1,000
pounds (40 CFR 302.4).
The National Response Center hotline for reporting spills is
(800) 424-8802.
EPA also maintains a RCRA/Superfund hotline for
information. This number is (800) 424-9346; in
Washington, D.C., the number is (703) 412-9810.
Resource Conservation and Recovery Act (RCRA)
The major objectives of RCRA are to protect human health and
the environment while conserving valuable material and energy
resources. The Act is concerned with all stages in the hazardous
waste management cycle – generation, storage, transportation
and disposal – and requires notification to EPA within 90 days
by anyone who generates, transports, treats, stores or disposes of
the specific covered wastes.
For styrene, discarded off specification product, spill cleanup
residue and empty styrene containers are not considered
listed hazardous waste (40 CFR 261.33). However, liquid
waste material should be evaluated for the characteristics of
ignitability (40 CFR 261.21).
Mixtures of styrene and styrene solutions destined for
disposal which exhibit flash points less than 140°F are also
considered ignitable hazardous waste (40 CFR 261.21).
Styrene is included in the list Hazardous Constituents
Subject to Groundwater Monitoring (40 CFR 264,
Appendix IX). This requirement pertains only to facilities
that have obtained a permit for storage, treatment or disposal
of hazardous waste and are subject to groundwater
monitoring requirements.
Section 311 (40 CFR 116.4) List of Chemicals considered
hazardous if spilled in navigable waters. Regulations specify
spill procedures to be followed in the event of accidental
spillage. Styrene is listed.
Section 311 (40 CFR 117.3) Reportable Quantities of
Designated Hazardous Substances. Styrene has a reportable
quantity of 1000 pounds (reportable quantity category B).
Product Safety Bulletin 67
Appendix 5. Regulatory Summary
Safe Drinking Water Act (SDWA)
The 1974 SDWA directed the EPA to promulgate primary
drinking water regulations which specify contaminants which
may have an adverse effect on human health and to specify
either maximum contaminant levels (MCLs) or treatment
techniques.
A MCL of 0.1 mg/l applies to styrene.
Under Section 1445(a)(1) of the SDWA, the EPA issued
regulations requiring public water systems to conduct
monitoring for specified contaminants.
Styrene is a listed chemical for which monitoring is required
(40 CFR 141.40).
The 1986 amendments to the SDWA required the EPA to
establish a priority list of contaminants which are known or
anticipated to occur in public water systems and which “may”
require regulation under the SDWA. Under these amendments,
the EPA also was required to publish maximum contaminant
level goals (MCLGs) for the listed substances.
Styrene is listed as one of the substances which the EPA
substituted for a Congressionally mandated substance on the
list of Statutory Contaminants (53 FR 1892, 1/22/88). The
MCLGs for styrene is 0.1 mg/l.
EPA’s Safe Drinking Water hotline is (800) 426-4791.
Department of Transportation (DOT)
The Hazardous Materials Transportation Act of 1974 gave the
Department of Transportation authority to regulate the
transportation of hazardous materials in interstate commerce.
DOT regulates such matters as classification, packaging and
hazard communication (labelling). DOT also has established
spill notification requirements. Regulations governing the
transport of hazardous materials can be found at 49 CFR 172
and 173.
Styrene is listed as Hazard Class 3; the proper shipping name
is Styrene Monomer, Inhibited; the identification number
assigned to the proper shipping name is UN 2055; packing
group III. The hazard label required is “Flammable Liquid.”
On November 5, 1992, DOT issued a final rule (57 FR 52930)
which amended the Hazardous Material Regulations to list
materials identified as marine pollutants by the International
Maritime Organization.
Styrene Monomer, Inhibited, is cited on the list of marine
pollutants (49 CFR 172.101, Appendix B).
Occupational Safety & Health Administration
(OSHA)
The following OSHA regulations may apply to styrene and,
where appropriate, are described in more detail in various
sections of this document.
29 CFR 1910.106, Subpart H - Storage of flammable and
combustible liquids.
68 Product Safety Bulletin
29 CFR 1910.146 - Permit-required confined spaces.
(Effective 4/15/93)
29 CFR 1910.155, Subpart I - Fire protection relative to
flammable or combustible liquids.
29 CFR 1910.164 - Fire detection systems required when
styrene is in use.
29 CFR 1910.1000, Subpart Z, Permissible Exposure
Limits.
Table Z-1-A
TWA: 50 ppm; 215 mg/m3
STEL: 100 ppm; 425 mg/m3
OSHA revoked these levels on June 30, 1993 (58 FR 35338)
as a result of a court decision. They remain in this document
since the following OSHA state plans continue to enforce
them: Alaska, California, Connecticut, Maryland, Michigan,
Minnesota, New Mexico, Vermont and Washington. The
Virgin Islands also are enforcing the 1989 PELs. It also is
Lyondell Chemical Company’s intent to abide by either
these levels or the ACGIH levels where the latter provide
more protection.
Table Z-2
8-Hour TWA: 100 ppm.
Acceptable Ceiling Concentration: 200 ppm.
Acceptable Maximum peak above the acceptable
ceiling concentration for an 8-hour shift: 600 ppm.
Maximum duration of acceptable maximum peak:
five minutes in any three hours
29 CFR 1910.1200, Hazard Communication Standard.
Styrene appears on one of the lists specifically cited at
29 CFR 1910.1200(d)(3). Chemicals on these lists
automatically are considered as hazardous and are subject
to HCR requirements.
Superfund Amendments & Reauthorization Act
(SARA)
Sections 302/304 of SARA detail emergency planning and
emergency notification requirements under which facilities
must report releases of extremely hazardous substances and
CERCLA-listed hazardous substances in excess of threshold
planning quantities (TPQs) and RQs. Facilities also must
submit copies of MSDSs (Sections 311/312) and report
emissions of toxic chemicals (Section 313).
Styrene is not listed as an extremely hazardous substance
(Section 302; 40 CFR).
Lyondell Chemical Company has classified styrene as
an immediate (acute) health hazard; as a delayed (chronic)
health hazard; as a fire hazard; and as reactive
(Sections 311/312).
Styrene is listed as a toxic chemical (Section 313;
40 CFR 372) and is subject to Toxic Release Inventory
Reporting. The de minimis concentration level of
0.1 percent; supplier notification is required.
Appendix 5. Regulatory Summary
Toxic Substances Control Act (TSCA)
The Toxic Substances Control Act gives the EPA authority to
regulate production, use, labeling, distribution and/or disposal
of chemical substances and mixtures; to delay production; to
ban or restrict manufacturing or marketing of existing or new
chemical substances which present an unreasonable risk of
injury to health or the environment; to require testing,
recordkeeping and reporting. All manufacturers, importers,
processors, distributors and disposers of chemical substances
subject to the law are affected by its provisions and
implementing regulations.
Section 8(b) Chemical Substances Inventory - Styrene is
listed.
Section 12(b) Export Notification (40 CFR 707, Subpart D)
- Styrene is not listed.
Information on TSCA regulations can be obtained from the
TSCA Assistance Office at the EPA (202) 554-1404.
State
California
California Safe Drinking Water & Toxic Enforcement Act of 1986
(Prop. 65)
Prop. 65 prohibits discharge of chemicals “known to the state”
to cause cancer or reproductive toxicity into drinking water
supplies. An employer must notify all workers of possible
exposure to a chemical. Facilities must also provide the state and
local agencies with information regarding spills or releases of
these chemicals to the environment.
Styrene is not listed.
Additional information about Prop. 65 can be obtained from
the Office of Environmental Health Hazard Assessment’s
Proposition 65 Implementation Office at (916) 445-6900.
Connecticut
Connecticut Manufacturing Employer Hazardous Materials
Notification Act
This law requires any manufacturing employer who “uses,
produces or stores any hazardous material” to complete a survey.
Hazardous materials are defined by reference to the federal
Department of Transportation hazardous material table. Also
included as hazardous materials are federal RCRA hazardous
wastes and federal CERCLA hazardous substances.
Styrene is listed.
The authority for these regulations is Connecticut Gen. Stat.
Ann., Section 29-307a.
Florida
Florida Employee Right-to-Know Law
Provisions of this law require employers to give local fire
departments a list of plant areas containing “toxic substances.”
Toxic substances are those recommended by the state’s Toxic
Substances Advisory Council.
Styrene is designated as a toxic substance.
The authority for this list is Florida Statutes Annotated, Section
442.101.
Illinois
Illinois Toxic Substances Disclosure to Employees Act
Under the Illinois Right to Know Law, known as the Toxic
Substances Disclosure to Employees Act, employees are required
to inform workers of potential hazards, safety precautions and
emergency procedures concerning exposure to toxic substances
in the workplace.
Styrene is defined as a toxic substance.
Illinois Chemical Safety Act
Under this law, covered businesses using, storing or
manufacturing defined chemical substances must have a written
Chemical Safety Contingency Plan.
Styrene is a covered substance.
The authority for these requirements is Illinois Rev. Statute,
Chapter 111 1/2, Paragraph 951.
Louisiana
Louisiana Hazardous Materials Information, Development,
Preparedness and Response Act
This law subjects covered facilities to “right-to-know” type
requirements. Covered materials include federal SARA
extremely hazardous substances and any hazardous chemicals as
defined under the federal OSHA standard.
Styrene is listed with a reportable quantity of 1000 pounds.
The authority for these regulations is Louisiana Admin. Code,
Title 33, Chapter 39.
Product Safety Bulletin 69
Appendix 5. Regulatory Summary
Massachusetts
New York
Massachusetts Right-to-Know Law
This law established reporting, labeling, MSDS, recordkeeping
and related regulations for certain toxic or hazardous substances.
Styrene is listed on the Massachusetts Substance List as an
extraordinarily hazardous substance with a one ppm
threshold and as a carcinogen.
Questions about the regulations can be directed to The
Commonwealth of Massachusetts, Executive Office of Human
Services, Department of Public Health, Bureau of
Environmental Health Assessment, 250 Washington Street,
Boston, MA 02108-4619, (617) 624-6000.
Massachusetts Spill Reporting
The Oil and Hazardous Materials List establishes reportable
quantities (RQs) for substances which require reporting of
unauthorized discharges. Styrene is listed with an RQ of
50 pounds.
New York Bulk Storage Registration/Release Reporting
New York requires the registration of bulk storage tanks and
notification of releases of listed hazardous substances under the
Substances Hazardous or Acutely Hazardous to Public Health,
Safety or the Environment Act and the Hazardous Substances
Bulk Storage Act.
Styrene is listed with an RQ for releases to air of
1000 pounds; and an RQ for releases to land/water of
1 pound.
Authority is found in New York Comp. Codes R & Regulations,
Parts 595 through 599.
New Jersey
New Jersey Worker & Community Right-to-Know Act
This law requires facilities containing, distributing or handling a
hazardous substance to complete a Right-to-Know survey. The
survey provides workers and the community with information
pertaining to the specific hazardous substance.
Styrene is listed on the New Jersey Hazardous Substance List.
The New Jersey I.D. number is 1748; the New Jersey
hazardous material number is 2055. Styrene is listed as an
environmental hazard subject to state release reporting and
with a zero inventory reporting threshold. Styrene also is
designated as a New Jersey special hazard subject to
restriction of trade secrecy claims.
Regulations are codified in the New Jersey Administrative Code,
Title 8, Department of Health and Senior Services, Chapter 59.
Additional information is available from the State of New Jersey
Department of Health and Senior Services, CN 360, Trenton,
NJ 08625-0360.
New Jersey Spill Tax
New Jersey has established a list of substances defined as
hazardous according to the Spill Compensation and Control Act
(N.J. Statutes, Annotated, Section 58:10-23.11 et seq.).
Styrene is a listed substance.
The authorities for the listing are New Jersey Administrative
Code, Section 7:1E-1.3.
70 Product Safety Bulletin
Pennsylvania
Pennsylvania Worker & Community Right-to-Know Act
This law requires facilities or distributors handling hazardous
substances to complete a Hazardous Substances Survey Form
(HSSF) annually for the previous calendar year. The HSSF lists
chemicals as an environmental hazard or special hazard.
Styrene is listed as an environmental hazard with a threshold
of 1 percent.
Additional information is available from the Pennsylvania
Department of Labor and Industry, Bureau of Penn. Safe.
Rhode Island
Rhode Island Hazardous Substances Right-to-Know Act
This law requires employers who use, transport, store or, in any
other manner, expose employees to toxic or hazardous
substances, as defined by the state, to provide notice, labeling
and training.
Styrene is listed with the hazard code “CTF” = Carcinogenic;
Toxic; Flammable.
The authority for these regulations is Rhode Island General
Laws 28-21-1.
Appendix 5. Regulatory Summary
International
Philippines
Australia
Philippine Inventory of Chemicals and Chemical Substances
(PICCS)
Styrene is listed.
Australian Inventory of Chemical Substances (AICS)
Styrene is listed.
Canada
Canadian Workplace Hazardous Materials Information System
(WHMIS)
WHMIS established requirements for classifying hazardous
substances that will be used in the workplace and for preparing
MSDSs and container warning labels. Substances are classified
by the manufacturer or importer to determine whether or not
they are controlled products. When a product has been
evaluated and is found to be a controlled product, the ingredient
disclosure list (IDL) must be consulted and any ingredient
present in a concentration greater than that specified must be
disclosed on the MSDS.
Lyondell Chemical Company has classified styrene as Class
B2 (Flammable Liquids); Class D2A (Very Toxic Material);
and Class F (Dangerously Reactive Material). Styrene is listed
on the IDL as a substance which must be disclosed if the
weight-to-weight concentration in the product is 0.1 percent
or greater. The WHMIS number is 1473.
Canadian Domestic Substances List
Styrene is listed.
Miscellaneous
National Fire Protection Association (NFPA) Hazard Rating
The NFPA ratings assign a numeric value to specific aspects of
each hazard. Ratings for styrene are as follows:
Health: 2. Materials hazardous to health, but areas may be
entered freely with full-faced mask self-contained breathing
apparatus which provides eye protection.
Flammability: 3. Materials which can be ignited under
almost all normal temperature conditions. Water may be
ineffective because of the low flash point.
Reactivity: 2. Materials which (in themselves) are normally
unstable and readily undergo violent chemical change but do
not detonate. Includes materials which can undergo violent
chemical change at elevated temperatures and pressures. Also
includes these materials which may react violently with water
or which may form potentially explosive mixtures with water.
In advanced or massive fires, fire fighting should be done
from a safe distance or from a protected location.
Additional information on the NFPA hazard rating system can
be obtained from the National Fire Protection Association,
Batterymarch Park, Quincy, MA. 02269, (800) 344-3555.
China
Chinese Inventory of Existing Chemical Substances
Styrene is listed.
European Economic Community
European Inventory of Existing Commercial Chemical Substances
(EINECS)
Styrene is listed on EINECS - number 202 851 5. Listing on
EINECS is accepted by certain other European countries
which have adopted EINECS as their base inventory; i.e.,
Austria, Finland, Switzerland. However, other “registration”
requirements may apply in those countries.
Japan
Japanese List of Existing & New Chemical Substances (ENCS)
Styrene is listed. The ENCS number is (3)-4.
Korea
Korean List of Existing Chemicals (ECL)
Styrene is listed; the Korean listing number is KE-35342.
Product Safety Bulletin 71
APPENDIX 6. VISUAL QUICK TEST
To Determine ppm of TBC Inhibitor
Present in Styrene Monomer
This is a visual method. Analytical methods are
available on request.
Visual Method
Standard solutions – Prepare a series of solutions containing
5, 10, 15, 20 and 25 ppm (and others as necessary)
4-tert-Butylcatechol in uninhibited styrene.
Prepare the uninhibited styrene by extracting inhibited
styrene with successive portions of 4 percent potassium
hydroxide until no pink color is produced in the caustic layer.
These standards must be prepared at the time of each analysis.
Procedure
1. Add 50 ml. of the sample and of each standard to respective
125 ml. separatory funnels by means of suitable graduates.
2. Add 25 ml. of 4 percent potassium hydroxide to each funnel
and shake for five minutes.
3. Allow the layers to separate and filter the lower layer
through fluted filter paper into respective 50 ml. nessler
tubes.
4. Allow the filtrates to stand for 15 minutes.
5. Compare the pink color of the sample solution with the
standards.
6. Report the 4-tert-Butylcatechol content of the sample as the
concentration of the standard which matches the sample. If
the color of the sample is between two of the standards,
report the content of the sample as between the
concentrations of these standards.
Product Safety Bulletin 73
APPENDIX 7. GLOSSARY
ACGIH – American Conference of Governmental Industrial
Hygienists
AFFF-AR – aqueous film-forming foam, alcohol resistant
AIHA – American Industrial Hygienists Association
ANSI – American National Standards Institute
API – American Petroleum Institute
ASME – American Society of Mechanical Engineers
ASTM – American Society for Testing and Materials
BOD – biochemical oxygen demand
Bonding – the connection of two or more conductive objects by
means of a conductor (most commonly a wire or metal plate)
CAAA – Clean Air Act Amendments
CANUTEC – Canadian Transport Emergency Centre
CERCLA – Comprehensive Environmental Response,
Compensation, and Liability Act
CFR – Code of Federal Regulations
CGI – combustible gas indicators
CHEMTREC – Chemical Transportation Emergency Center
COD – chemical oxygen demand
Confined space – an area that by design has limited openings for
entry and exit. A confined space has unfavorable natural
ventilation and is not intended for continuous worker
occupancy.
CPC – chemical protective clothing
DOT – Department of Transportation, United States of
America
EPA – Environmental Protection Agency, United States of
America
Flash point – the minimum temperature at which a liquid gives
off vapor in sufficient concentrations to form an ignitable
mixture with air near the surface of a liquid
GAC – granular activated carbon
Grounding – the connection of one or more conductive objects
to the ground; a specific form of bonding. Grounding is also
referred to as earthing.
HAP – hazardous air pollutant
HazWOpEWR – Hazardous Waste Operations and Emergency
Response
IARC – International Agency for Research on Cancer
IATA – International Air Transport Association
ICAO – International Civil Aviation Organization
IDLH – immediately dangerous to life and health; the airborne
concentration of a toxic material from which one could
escape within 30 minutes without any escape-impairing
symptoms or any irreversible health effects
IM – intermodal
IMDG – International Maritime Dangerous Goods
IMO – International Maritime Organization
ISO – International Standards Organization
KOC – soil adsorption/mobility; the partitioning of a chemical
between soil or sediment, usually expressed as K (the
concentration of a chemical in soil (µg/g) to that in water
(µg/ml) or as Koc (which is K divided by the organic carbon
content of the soil or sediment)
LEPC – local emergency planning committee
LFL – lower flammability limit
MACT – maximum achievable control technology
MSDS – material safety data sheet
MSHA – Mine Safety and Health Administration
NEC – National Electric Code
NFPA – National Fire Protection Association
NIOSH – National Institute for Occupational Safety and
Health
NPDES – National Pollutant Discharge Elimination System
OSHA – Occupational Safety and Health Administration
Outage – amount by which a packing falls short of being
liquid full
POTW – publicly owned treatment works
PPE – personal protective equipment
ppm – parts per million
RCRA – Resource Conservation and Recovery Act
RQ – reportable quantity
SARA – Superfund Amendment and Reauthorization Act
SCBA – self-contained breathing apparatus
SIP – state implementation plan
STEL – short-term exposure limit
TOC – total organic carbon
TPQ – threshold planning quantity – under the Superfund
Amendments Reauthorization Act (SARA Title III) Section
302, 304, 311/312, a chemical specific quantity, in pounds
that triggers certain reporting requirements
TWA – time-weighted average
UL – Underwriters Laboratory
Ullage – amount by which a packaging falls short of being
liquid full
UN – United Nations
Vapor pressure – the pressure exerted by a volatile liquid while
under defined equilibrium conditions. Vapor pressure is
usually measured in millimeters of mercury (mm Hg),
pounds per square inch, bar or Pascal.
VOC – volatile organic compound
Product Safety Bulletin 75
World Headquarters
Lyondell Chemical Company
1221 McKinney
Houston, TX 77010
Tel (713) 652-7200
Toll-free (888) 777-0232
 
European Headquarters
Lyondell Chemical Europe, Inc.
P. O. Box 2416
3000 CK Rotterdam
The Netherlands
Tel (31-10) 275-5500
Tel (33-3) 4424-9205 (tech service)
 
Lyondell South America
Av Roque Petroni Jr,
999, cj 123
Sao Paulo, SP 04707-910
Brazil
Tel (55-11) 5184-8400
 
Asian Headquarters
Lyondell Asia Pacific, Ltd.
41st Floor – The Lee Gardens
33 Hysan Avenue
Causeway Bay, Hong Kong
Tel (85-2) 2882-2668
Tel (33-3) 4424-9205 (tech service)
www.lyondell.com
The information in this document is, to our knowledge, true and accurate. However, because the particular uses and actual conditions of use of our
products are beyond our control, it is the customer’s responsibility to determine whether a product is appropriate and suitable for the customer’s specific
use. All uses of Lyondell products and any written or oral information, suggestions, or technical advice from Lyondell is without warranty, express or
implied, and is not an inducement to use any process or product in conflict with any patent. More detailed safety and disposal information on our products
is contained in the Material Safety Data Sheet (MSDS).  All users of our products are urged to retain and use the MSDS. You may request a copy by going to
our Web site: www.lyondell.com. You can also obtain an MSDS by calling (800) 700-0946 or (713) 309-7513.
 
3284-V3-1207
Supersedes July 2004 version