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ANOTHER EDITION OF….
DUSTY DEBBIE
blasts particulate
matters.
THE EMERGENCE OF
NEW DUST SAMPLERS FOR
NEW ISSUES
SPECIAL FOCUS:
2013 OSHA PROPOSED
RULEMAKING ON SILICA
WHY DO WE NEED NEW DUST
SAMPLERS?




New concerns with traditional samplers
New criteria for size-selective sampling
New regulations and guidelines
New priorities and demands from users
NEW CONCERNS
WITH TRADITIONAL SAMPLERS


US NIOSH and OSHA scientists have been
addressing sample losses with traditional
37-mm filter cassettes.
Of particular concern, are sample losses that
occur from particles that adhere to the interior
cassette walls and are not analyzed.
U.S. OSHA STATEMENT
IN HEXAVALENT CHROMIUM METHOD
“Tests showed that Cr (VI) equivalent to 0 to
123% of the amounts found on the PVC filter
were present on the interior walls of cassettes
used for compliance samples. It is now
routine procedure to wipe interior walls of
sampling cassettes for all metal samples
analyzed.”
Source: United States. Occupational Safety and Health Administration.
Hexavalent Chromium. 30 Apr 2009 <http://www.osha.gov/dts/sltc/methods/
inorganic/id215_v2/id215_v2.html>
NIOSH STATEMENT
IN AIHA JOURNAL ARTICLE


Dust deposits on the walls of filter cassettes
were 19% of the total sample for lead and
25% of the total sample for copper.
Filter cassettes should be rinsed and wiped
prior to analysis.
Source: Ashley, Kevin, Harper, Martin and Demange, Martine.
“Concerning Sampler Wall Deposits in the Chemical Analysis of
Airborne Metals.” Journal of Occupational and Environmental
Hygiene 4:9 Sept 2007: D81 - D86
<http://dx.doi.org/10.1080/15459620701493149>
ACCU-CAP EMERGES
TO ADDRESS CONCERNS



Filter insert that is
placed into a 2-piece
cassette with support
pad.
Consists of a clear
plastic dome heatsealed to a filter.
Dust is collected onto
the filter or within the
dome for gravimetric
analysis.
PVC ACCU-CAP
FOR
GRAVIMETRIC
ANALYSIS
A NEW SOLU-CAP EMERGES
BASED ON NIOSH RESEARCH




Designed for chemical analysis of metals
Mixed cellulose ester filter heat sealed to acid
digestible cellulose acetate dome
Pre-loaded into 2-piece cassettes with
support pads
Eliminates the need to wipe the inside of the
cassette to obtain reliable exposure
measurements Source: Ashley, Kevin, Harper, Martin. “Acid-Soluble
Internal Capsules for Closed-Face Cassette Elemental
Sampling and Analysis of Workplace Air.” Journal of
Occupational and Environmental Hygiene 10:6, 297-306,
February 25, 2013.
NEW CRITERIA
FOR SIZE-SELECTIVE SAMPLING


In 1993, ACGIH joined with ISO and CEN in
defining particulates in terms of inhalable,
thoracic, and respirable particulate mass
fractions.
See page 80 of the 2013 TLV handbook.
NOTE FOR NEWCOMERS:
CURRENT PARTICULATE FRACTIONS
Inhalable-particles that are hazardous when
deposited anywhere in the respiratory system
(including those that enter nose/mouth)
 Thoracic-particles hazardous when deposited
anywhere within the lung airways and gasexchange region
 Respirable-particles hazardous when
deposited in the alveolar gas-exchange
region.

PERFORMANCE SPECS FOR
DUST SAMPLERS
Sampling Efficiency, E, %
100
75
Inhalable
50
25
Respirable
Thoracic
0
1
10
Aerodynamic Particle Diameter, da, m
100
INHALABLE PARTICULATE:
A CLOSER LOOK
Review of pertinent scientific
issues presented at an AIHCE
session
The impact on dust samplers

HISTORICAL PERSPECTIVE:
TERMS AND SPECIFICATIONS


Except in cases where diseases are caused
by fine respirable dust, it has been common
practice to sample so-called total dust.
This is in general recognition that all inhaled
particles could present either a specific or
non-specific risk to health. (Mark and Vincent, Ann.
Occup. Hyg.,1986.)
PROBLEMS WITH TOTAL DUST:
SPECIFICATIONS


Total dust has never been defined by a
specific size range and a 50% cut-point (D50)
was never established for total dust samplers.
Given the vague definition of total dust, a
number of personal samplers with various
performance characteristics have been used
for sampling total dust around the world.
TOTAL DUST SAMPLERS
USED GLOBALLY
37- or 25mm filter
cassettes
Single-hole
head
7-hole
head
SURPRISING STATISTICS:
SAMPLER PERFORMANCE


There is very limited data available on how
well these samplers actually measure the true
dust exposure.
Studies show considerable differences in
results from these various samplers when
sampling the very same dust under the
identical environmental conditions. (Mark and
Vincent, 1986)
≠
≠
SURPRISING STATISTICS:
LIMITATIONS OF 37-MM CASSETTES
37-mm Filter Cassettes:




Were never designed to represent a
physiologically relevant exposure to the
respiratory system.
Aspiration efficiency is not very similar to the
nose and mouth.
Are not 100% efficient in collecting all sizes
of dust particles.
Have a upper size limit (approx. 30 um)
where efficiency falls to zero.
(T. Renee Anthony, AIHCE 2011)
SURPRISING STATISTICS:
ERRORS WITH 37-MM CASSETTES
Sampling errors with 37-mm cassettes
can occur from:



Ambient wind velocity effects
Orientation effects
Dust deposition on walls of cassette
INHALABLE SAMPLERS
EMERGE

Since occ hygienists are concerned with the
health-related dose, new dust samplers have
emerged that measure dust concentrations
with the same efficiency as we inhale them.
THE IDEAL DUST SAMPLER


An inhalable sampler is considered ideal
“when a personal sampler mounted on the
body gives the same measured dust
concentration and aerodynamic size
distribution as that inspired by its wearer,
regardless of dust source location and wind
conditions”. (Mark and Vincent, 1986)
Inhalable samplers have a 50% cut-point of
100 microns.
INHALABLE SAMPLERS:
FOR THE NEW CRITERIA

The first personal
sampler specifically
designed for inhalable
particulate mass was
developed by Mark and
Vincent in 1986 at the
Institute of Occupational
Medicine in Scotland
and was licensed to
SKC Ltd. in the U.K.
SKC 225-70A
ADVANTAGES OF THE IOM
SAMPLER: TECHNICAL





Developed specifically to match the inhalable
definition.
Precise fit to the inhalable curve at 2 L/min
Conductive plastic cassette for gravimetric and
stainless steel cassette for chemical analysis.
Internal wall deposits are included in the sample
analysis.
Can be combined with a foam insert to collect
the respirable fraction simultaneously.
ADVANTAGES OF THE IOM
SAMPLER: CONFORMANCE


The IOM is specified by name in many
standards/methods including UK HSE Method
14/3; Australian Standard 3640, and NIOSH
Method 5700.
In response to an SKC inquiry, U.S. OSHA
issued a statement indicating the IOM could
be used as an equivalent sampler for
particulates not otherwise classified. Copies
available upon request.
OTHER INHALABLE SAMPLERS:
BUTTON SAMPLER



Designed for use at
4 L/min to enhance
sensitivity
Inlet has a stainless
steel inlet screen to
keep out large, noninhalable projectiles
from impacting or
splashing onto the filter.
Suitable for area or
personal sampling.
SKC 225-360
SWEDISH MINI-SAMPLER FOR
INHALABLE MANGANESE


Enable positioning of
the sampler inlet within
close proximity of the
welder’s nose and
mouth even when
wearing a face shield.
Used with the SKC
Face Level Sampling
Head Set
Developed in a research project
partly funded by the Swedish Work
Environment Authority and carried
out at Stockholm University,
Sweden.
Mini-Sampler SKC 225-6201
Headset
SKC 225-6200
MINI-SAMPLER COMPONENTS
Figure 1



13-mm Swinnex filter holder modified into an openface filter holder.
Incorporates a specially designed aluminum entry
nozzle which protrudes out the front of the holder as
the sampler inlet.
PTFE-coated O-ring and the retaining ring
holds the 13-mm filter in place in the sampler body.
MINI-SAMPLER:
ADVANTAGES/APPLICATIONS
Advantages: The headset mounting
arrangement improves personal sampling as it
maintains the sampler close to nose/mouth.
Applications: Only for inhalable sampling where
90% of the mass size distribution is below 20
um (including manganese).
DATA COMPARISON??
TOTAL VS INHALABLE
Inhalable particulate mass is typically greater
than so-called total particulate mass.



How much greater will depend upon the SIZE of the
particles.
With larger particles, inhalable particulate mass will
be much greater than total particulate mass.
With smaller particles, inhalable and total particulate
mass will be comparable.
A CONVERSION FACTOR??
TOTAL VS INHALABLE

The AIHCE session
made the point that
it is really not
enough to use a
simple conversion
factor from total to
inhalable as there
are too many
variables.
So what do you do?

Collect side-by-side
37-mm cassette and
inhalable samples
and determine
process-specific
conversion factors
for YOUR unique
application.
2013 TLVs®
ISSUED AS INHALABLE




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

Acrylamide
Alachlor
Aldrin
Asphalt Fume
Azinphos-methyl
Benomyl
Beryllium
Borate cpds,
Inorganic
Butylated
hydroxytoluene










Calcium sulfate
Caprolactam
Captan
Carbaryl
Carbofuran
Carbon Black
Chlorpyrifos
Citral
Coumaphos
Cresol, all isomers
2013 TLVs®
ISSUED AS INHALABLE










Demeton (and
Demeton- S-methyl)
Diazinon
Dibutyl phosphate
2,2-Dichloropropionic
acid
Dichlorvos (DDVP)
Dicrotophos
Dieldrin
Diesel Fuel
Diethanolmine
Dioxathion












Diquat
Disulfoton
Endosulfan
EPN
Ethion
2-Ethylhexanoic acid
Fenamiphos
Fensulfothion
Fenthion
Ferbam
Flour Dust
Fonofos
2013 TLVs®
ISSUED AS INHALABLE










Glyoxal
Hexahydrophthalic
anhydride
Iodine and Iodides
Isobutyl nitrite
Magnesium oxide
Malathion
Maleic anhydride
Methyl demeton
Methyl parathion
Mevinphos







Mineral oil, excluding
metal working fluids
Molybdenum (Metal and
insoluble cpds.)
Monochloroacetic acid
Monocrotophos
Naled
Natural rubber latex as
total proteins
Nickel, Elemental,
Soluble and Insoluble
Cpds.
2013 TLVs®
ISSUED AS INHALABLE








Nickel Subsulfide
5-Nitro-o-toluidine
p,p-Oxybis(benzene
sulfonyl hydrazide)
Parathion
Particulates Not
Otherwise Specified
(now a guideline; not a
TLV)
Phorate
m- and oPhthalodinitrile
Piperazine and salts








Ronnel
Silicon carbide,
nonfibrous
Sulfotepp (TEDP)
Sulprofos
Synthetic Vitreous
Fibers (Continuous
filament)
Temephos
Terbufos
1,1,2,2Tetrabromomethane
2013 TLVs®
ISSUED AS INHALABLE





Tetrethyl pyrophosphate
(TEPP)
Thallium
4,4-Thiobis(6-tert-butylm-cresol)
Thiram
Trichlorphon




Trimellitic anhydride
Vanadium pentoxide
Wood Dusts
Xylidine (mixed
isomers)
2013 INTENDED CHANGES TO TLVs®
ISSUED AS INHALABLE








Clopidol
2,4-D
Diethylene glycol
monobutyl ether
Manganese, elemental
and inorganic cpds.
O-Phthalodinitrile
Piperazine and salts
2,4- or 2,6- Toluene
diisocyanate
Tributyl phosphate
For TLVs with IFV notation
(Inhalable fraction and
vapor)


There is no single
sampler that can be
used.
Requires (2) separate
samples: one for each
contaminant phase.
THORACIC PARTICULATE:
A CLOSER LOOK
Definitions of size
fraction
Specifications for
samplers
Sampler options
Applications

THORACIC PARTICULATE
DEFINED


Thoracic particulate is defined as material
hazardous when deposited within the lung
airways and down into the gas exchange
region.
Thoracic samplers have a 50% cut-point of
10 um.
THORACIC SAMPLERS
EMERGE



The first thoracic
sampler was developed
by BGI Inc.
The BGI GK 2.69
cyclone is used with
standard 37-mm
cassettes at a flowrate
of 1.6 L/min.
This sampler is listed in
the NIOSH method for
metalworking fluids.
THORACIC SAMPLERS:
ANOTHER OPTION


SKC 225-386
Single-use, disposable
model 225-386
U.S. Patent No. 7,073,402
SKC offers an impaction
based sampler for
thoracic particulate
called the Parallel
Particle Impactor or PPI.
The thoracic PPI is used
with any suitable
37-mm filter at a flowrate
of 2.0 L/min.
PPI OPERATING PRINCIPLE



The disposable PPI
looks like a traditional
37-mm filter cassette.
But the inlet section has
4 internal, pre-oiled
impactor plates that
scrub out larger
particles.
The dust size-fraction of
interest is collected onto
the filter in the outlet
section for analysis.
PERFORMANCE OF SKC AND
BGI THORACIC SAMPLERS
100
Penetration, P, %
GK2.69 (BGI)
75
Thoracic PPI, QS=2.0 Lpm
50
25
Thoracic Convention
0
0.5
1
5
10
Aerodynamic Particle Diameter, da, m
50
THORACIC SAMPLERS
CURRENT APPLICATIONS
Thoracic TLVs


Sulfuric Acid
Cotton Dust
NIOSH Methods

NIOSH Method 5524,
for metalworking fluids
specifies a
2-um PTFE filter in a
37-mm filter cassette
with an optional thoracic
particulate sampler.
RESPIRABLE DUST:
THE OSHA SILICA NPRM
U.S. OSHA published their
Notice of Proposed Rulemaking (NPRM)
for Occupational Exposure to Respirable
Crystalline Silica in September 2013 .

See this 757-page document at
https://www.osha.gov/silica/nprm.pdf

NOTABLE ISSUE IN THE NPRM:
PELs-CURRENT
GENERAL INDUSTRY
A formula based on the % silica
in the air sample. Example:
_____10____
% Quartz + 2
PEL is equivalent to 100 ug/m3
when the material is pure
quartz . PEL approaches 5
mg/m3, (the PEL for Particulates
Not Otherwise Classified) with a
low percentage of quartz in the
sample.
CONSTRUCTION AND
SHIPYARDS
A formula based on obsolete
method of collecting dust into
impingers with analysis by
particle counting.
PEL is approximately
equivalent to 250 ug/m3.
NOTABLE CHANGE IN THE NPRM:
PEL-PROPOSED
50 ug/m3 as an 8-hr TWA for all forms of
silica including quartz, cristobalite, and
trydymite for all industry sectors covered by
the rule.


25 ug/m3 action level (same as current TLV)
NOTABLE ISSUE IN THE NPRM:
SAMPLER SPECS-CURRENT
Current specs for respirable dust samplers were
promulgated in 1971 and are listed in 29 CFR
1910.1000; Table Z-3 for mineral dusts.

Table Z-3 lists the required collection efficiencies of
samplers for various particle sizes. Ex. Particles with a
diameter of 3.5 um should be collected with 50%
efficiency. (50% cut-point) The 25, 75, and 90%
cut-points are also listed.

The Dorr-Oliver (nylon) cyclone is the only sampler
used by federal OSHA inspectors to meet these specs.

NOTABLE CHANGE IN THE NPRM:
SAMPLER SPECS-PROPOSED
Page 539: OSHA acknowledges that the current
collection efficiency specs for samplers are obsolete.

Page 542: OSHA states that crystalline silica
measurement should be determined by a sampling
device designed to meet the characteristics for particlesize-selective samplers specified in ISO 7708:1995 Air
Quality-Particle Size Fraction Definitions for
Health-Related Sampling.

ISO 7708:1995

This is the standard that ACGIH, NIOSH,
CEN, and most countries around the world
have already adopted.

The collection efficiency curve for respirable
dust samplers in this standard includes a
50% (median) cut-point of 4 um which is
more conservative than the existing OSHA
specification.
TRADITIONAL SAMPLERS:
TO MEET SPECS IN ISO 7708
CYCLONES FROM SKC/FLOWRATES
 Aluminum Cyclone @ 2.5 L/min-Listed in
NIOSH method. Published journal article .

G(S)-3 Cyclone @ 2.75 L/min-Listed in OSHA
NPRM on page 267. Published journal article.
TRADITIONAL SAMPLERS:
TO MEET SPECS IN ISO 7708
OTHER CYCLONES /FLOWRATES
 Dorr-Oliver @ 1.7 L/min
Listed in NIOSH method and NPRM
 Higgins-Dewell @ 2.2 L/min
European cyclone; Listed in NIOSH method
and NPRM
 BGI GK 2.69 @ 4.2 L/min
Listed in NPRM
NEW SAMPLER OPTIONS
Page 539: Adoption of this (ISO) definition by
OSHA would allow for workplace sampling to
be conducted using ANY particulate sampling
device that conforms to the ISO definition i.e.
collects dust according to the
particle collection efficiency curve specified in
the ISO standard.
RESPIRABLE PPI
SAMPLERS FROM SKC

Specifically
designed to
precisely match the
criteria for respirable
samplers specified
in the ISO 7708
standard.
SKC RESPIRABLE PPI:
FLOWRATE OPTIONS

Single-use, disposable
PPI models are
available for use at
either 2, 4, or 8 L/min.

This provides flexibility
in pump options,
sample duration, and
concentration.
2 L/min: 225-385
8 L/min: 225-384
4 L/min: 225-387
PPI SAMPLER PERFORMANCE
COMPARED TO CRITERIA
100
Penetration, P, %
75
Respirable PPI, 2.0 L/min
50
Respirable PPI, 4.0 L/min
Respirable PPI, 8.0 L/min
ISO/CEN Respirable Criteria
25
0
1
5
Aerodynamic Particle Diameter, da, mm
10
PPI DATA:
OSHA DOCKET
SKC submitted comments to the OSHA
docket on the silica NPRM with data on
the PPI. (Electronic copies are available).
 The data which was published in the Journal
of Physics shows that the collection efficiency of
the PPI is a close match to the ISO standard
and the bias is more acceptable than the HD
cyclone (listed in the NPRM.)

MEETING USER DEMANDS:
CONVENIENCE




Smaller size-fits under welding
helmet or PPE
No assembly of impaction
substrates
Pre-loaded with filters or lab loaded
like a traditional cassette
No cleaning after sampling
AND FINALLY…

Another disposable size-selective
sampler for diesel particulate.

Particulate emissions from diesel
exhaust are VERY small particles that
rapidly clump together to form particles
that are still submicron in size i.e. less
than 1 um in aerodynamic diameter.
DPM SAMPLER EMERGES
A single-use, disposable
filter cassette for DPM was
developed by U.S.
NIOSH mining division and
the technology was
transferred to SKC for
commercial production.
SKC 225-317
DPM SAMPLING TRAIN
 Cyclone
Removes non-respirable particles that
may overload the filter
 Internal Impactor Plate in Cassette
Removes respirable particles greater than
1.0 um in diameter
 Heat-treated Quartz Filter assembly
Collects DPM particles less than 1.0 um
in diameter for analysis of elemental
carbon (EC).
THANK YOU
FROM DUSTY DEBBIE
If you have questions or
need further information,
email me at
[email protected].