1. science
2. physics
3. nanotechnology

Life cycle aspects of nanomaterials
David Lazarevic and Göran Finnveden
Environmental Strategies Research
KTH - Royal Institute of Technology
Stockholm, Sweden
Title:
Life cycle aspects of nanomaterials
Authors:
David Lazarevic and Göran Finnveden
ISSN: 978-91-7501-821-8
TRITA‐INFRA‐FMS 2013:4
Division of Environmental Strategies Research
Department of Sustainable Development, Environmental Science and Engineering
School of Architecture and the Built Environment
KTH - Royal Institute of Technology
Stockholm, Sweden
https://www.kth.se/abe/om-skolan/organisation/inst/see/om/avd/fms
Printed by: US AB, Stockholm, 2013
FORWARD
This report consists of two parts, a comprehensive compilation of published and ongoing
research on nanomaterials from a lifecycle perspective, and an extended summary written in
Swedish.
The report is funded by the Swedish Governmental Commission charged with developing "A
national action plan for the safe use and handling of nanomaterials" (Dir. 2012:89). The
authors are grateful for the feedback received during this work from the investigator, Ethel
Forsberg, and the commission secretary. The authors have received valuable comments
during the work from Eva Hellsten, who has been the contact person in the investigation. The
authors are responsible for the content of this report and the views expressed herein are
those of the authors. The summary report in Swedish is also published by the Governmental
Commission in their report.
SUMMARY
Nanotechnology and nanomaterials have been promoted as having the potential to bring
benefits to many areas of research, and to positively contribute to sustainable development.
As such, this rapidly growing field is increasing attracting investments from governments and
businesses worldwide. At the same time, it is recognised that the application of
nanomaterials may pose a risk to human health and the environment.
The Swedish Government, therefore, released a Committee Directive (Dir. 2012:89) to
produce a National Action Plan for the Safe Use and Handling of Nanomaterials. KTH was
commissioned by the Governmental Commission, charged with developing this action plan,
to review the current state of knowledge on the environmental aspects of nanomaterials from
a life cycle perspective. The remit of this study was to: clarify the models best suited to
highlight issues related to the safe use of nanomaterials; summarize the results of current life
cycle research and difficulties in applying life cycle approaches to nanomaterials; identify ongoing research initiatives; propose priorities to achieve the level of knowledge required to
understand risks and opportunities of nanomaterials and nano-products; provide suggestions
for images to explain the importance of the life cycle perspective in the field of
nanomaterials.
There is a general consensus that the potential health and environmental risks of
nanomaterial should be evaluated over their entire life cycle. This report reviews the literature
on the application of life cycle assessment (LCA), risk assessment (RA) and substance flow
analysis (SFA) to nanomaterials and nanoproducts.
Whilst there is plenty of literature promoting the application of LCA, there are few studies
that apply LCA to the area of nanotechnology. Twenty five LCA studies of nanomaterials were
identified, including nanomaterial such as cadmium telluride, calcium carbonate, carbon
black, carbon nanofibres, carbon nanotubes, nanoclay, nanoscale platinum-group metals,
silica, silver, silicon, titanium and titanium oxide. Product systems studied include: auto-body
panels, biopolymers, coatings, electronic displays, electronic sensors, lithium-ion batteries,
photo voltaic systems, packaging and agriculture polymer films, nanomaterial production
processes, textiles and wind turbine blades. These studies only looked at parts of the life
cycle, with no quantitative studies addressing the impact of nanomaterials to human health
and the environment from the cradle to the grave. Results from these studies showed the
potential for a significant cumulative energy demand in the production of nanomaterials such
as carbon nanotubes and carbon nanofibres. However, this is reduced when taking into
consideration the small amounts of nanomaterials in products and the potential benefits
during the use phase, such as weight reduction.
It has been shown that the goal and scope definition is of vital importance to get meaningful
results, as the different properties and functions of nanomaterials need to be considered
when nano-enabled products are compared to conventional products. The life cycle
inventories of current LCA studies cannot be classified as comprehensive as they often lack
nanomaterial specific data related to the outputs of processes. Hence, populating life cycle
inventory databases with nanomaterial specific information, such as size and shape, is of
critical importance. Although the UNEP/SETAC framework for toxic impacts can in principle
be used for specific impacts causes by nanoparticles, life cycle impact assessment methods
currently lack characterisation factors for the release of nanoparticles indoors and outdoors.
Hence, no LCA studies to date have considered the human toxicity and eco-toxicity of
nanomaterials from a life cycle perspective with consideration of the nano-specific properties.
There is a consensus that the RA framework is applicable to nanomaterials. However, many of
the methodological steps with RA require further refinement or development. Although some
RAs have been conducted for nanomaterial according to standard RA protocols, studies have
concluded that, due to limited data and the presence of large uncertaitintites, it has not been
possible to complete full RAs for regulatory decicion making. There is a lack of measured
exposure data for nanomaterials, lack of validated exposure estimation models, extensive
uncertainties when characterizing nanomaterials and a lack of (eco)toxicological studies in a
variety of species. Hence, it is difficult to complete hazard identification, dose–response and
exposure assessments for most nanomaterials. Two approached to RA from a life cycle
perspective have been identified: ‘LC-based RA’ and ‘RA-complemented LCA’. RAcomplemented LCA combines life cycle and RA based methods and most publications and
risk analysis frameworks utilise this method.
SFA is occasionally applied prior to RA to estimate emissions, and has become the point of
departure for the development of emission assessment methods. SFA traditionally uses mass
as a measure of the stocks and flows of materials. Such an approach has been used to study
the flow of nanomaterials such as nano titanium dioxide, nano zinc oxide, nanosilver and
carbon nanotubes during waste incineration and landfilling of municipal solid waste and
construction waste. Furthermore, particle flow analysis has been used to account for the
relevant properties of nanomaterials such as particle size, and the processes that change the
number of nanoparticles such as agglomeration and disassociation of particles into ions. This
approach has been used to study the flows and stocks of nanosilver (in wound dressings,
textiles and electronic circuitry) and nano titanium dioxide (in sunscreens, paints and selfcleaning cement) during the use phase.
In light of this review of LCA, RA and SFA studies of nanomaterials, the following suggestions
identify some potential ways forward:
 Improved information concerning the use of engineered nanomaterials (ENMs)s. In order
to assess risk, information is needed on the volumes society uses, in which applications,
and in what forms.
 Improved information on emissions is required in order to assess the risks of ENMs. As a
first step, information is required on where emissions occur, which can be achieved
through undertaking simplified SFAs of ENMs. Methods for this need to be developed
where the reasonable worst-case assumptions can be made to assess whether further
detailed analysis is required. Those who place a material on the market should be able to
describe how the material will be disposed of or emitted to the environment.
 In depth SFA in specific cases. These cases can be selected for several reasons:
environmentally relevant ENMs, ENMs used in large quantities or ENMs that can be
considered representative of larger groups and thus can be used to develop and verify
the simplified models.
 Measurements. SFA is based upon existing and available data which in turn need to
come from actual measurements or model calculations, which in turn needs to be based
on measurements. Examples of important situations where actual measurements are
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required include exposure in the work environment, flows in waste water treatment
plants and flows associated with recovery processes and other waste management
activities.
Methods for the characterization of nanoparticles. The properties of nanoparticles can
change according to their shape and size. Nanoparticles need to be characterised in
ways that are relevant for emission measurements, exposure analysis and toxic effects.
Toxicological and eco-toxicological dose-response data are needed.
Models for exposure analysis require further development and need to be adapted for
nanoparticles.
Environmental impact assessment methods in LCA require further development and
need to be adapted for nanoparticles. As the methods for risk assessment of
nanoparticles are developed, there is a need for LCA methodology to follow and adapt.
Life-cycle inventory data for ENMs. LCA is heavily dependent on databases which have
been developed over the past decade. However, these databases are limited with regards
to ENM data. Life cycle inventory data is essential for the assessment of the potential
benefits and impacts of ENMs in a life cycle perspective.
Methods to develop life cycle data for emerging technologies. Nanotechnology is a field
experiencing rapid development; this also applies to manufacturing processes and their
environmental performance.
International cooperation with a Swedish perspective. Much of the data and methods
that are required for LCA should be developed in the context of international
cooperation. However, it may be important to develop life cycle data for products
manufactured in Sweden as some conditions may be country specific (for example, raw
materials and energy). Furthermore, other processes such as waste management may
have specific Swedish conditions.
The collaboration of industry, governmental agencies and research. Much of the data
which is required should be produced by industry. It is also important that governmental
agencies and researcher are involved in such work to ensure credibility and transparency.
Credible information to users. The safe use of ENMs and nanoproducts requires
informed users. Labelling and other forms information is needed to be designed so that
users in businesses, organizations, government agencies and consumers can make their
own informed decisions.
Avoid locking in a risk paradigm. Full risk assessments require copious amounts of data
and take a significant amount of time to complete. It would be expensive and inefficient
to complete risk assessments on every ENM and its specific application that is placed on
the market. Hence, one must be able to make effective decisions about the safe use of
ENMs without full risk assessments.
Avoid a ‘material for material’ paradigm. The number of ENMs can be vast. In order to
have effective processes, decisions can be taken without the complete data that is
require for each individual material. Decisions can be made for groups of materials, or
based on more simple criteria.
Resources for research in several fields. There is need for research on data and methods
that can be used for SFA, RA and LCA. Research is also needed on the use of ENMs,
policy instruments and decision theory.
SVENSK SAMMANFATTNING
1 INLEDNING .......................................................................................................................... I
2 ANVÄNDNING .................................................................................................................... I
3 LIVSCYKELPERSPEKTIV OCH METODER........................................................................... II
4 EMISSIONER AV NANOPARTIKLAR ............................................................................... VI
5 RISKBEDÖMNINGAR I LIVSCYKELPERSPEKTIV ........................................................... VIII
6 LIVSCYKELANALYSER AV NANOMATERIAL ................................................................ VIII
7 OM VAL AV METODER, BEGRÄNSNINGAR OCH UTVECKLINGSBEHOV ......................X
8 PÅGÅENDE FORSKNING................................................................................................. XII
9 REKOMMENDATIONER ................................................................................................. XIII
10 SLUTSATSER ................................................................................................................... XIV
11 REFERENSER ................................................................................................................... XVI
1
Inledning
Nanomaterial kan definieras på olika sätt, men gemensamt för de flesta definitioner är att det
handlar om material som innehåller partiklar som i någon dimension har en storlek på mellan
1 och 100 nm (se t.ex. European Commission, 2011). Partiklarna kan förekomma i fasta
material, på en fast yta, i en gasfas eller suspenderade i en vätska. Jämfört med traditionella
partiklar innebär den lilla storleken att ytan är mycket stor i förhållande till volymen.
Nanopartiklar kan också ha annorlunda egenskaper än större partiklar och egenskaperna kan
bestämmas av storleken och formen, inte bara av den kemiska sammansättningen.
Nanopartiklar kan transporteras på annat sätt än större partiklar eller lösta ämnen. Storleken
och formen på nanopartiklarna, och därmed egenskaperna, kan ändras under partiklarnas
olika faser i sina livscykler, från tillverkning till slutanvändning och efter emission till naturen.
Nanopartiklar kan förekomma naturligt och tillverkas. Nanomaterial har mött ett stort
intresse och det finns förväntningar om innovationer inom många områden och stark tillväxt.
Samtidigt finns det en oro att nanomaterial också kan vara miljö- och hälsofarliga. En del
ämnen i nanomaterial har dokumenterade miljö- och/eller hälsorisker. Dessutom finns en oro
att nanomaterial, genom sina speciella egenskaper, lättare kan exponera känsliga organismer
och organ.
2
Användning
Begreppet nanomaterial är vitt och täcker ett stort antal material och tillämpningar. Det finns
ingen samlad offentlig statistik om användning av nanomaterial. I termer av marknadsvolym
så är de viktigaste nanomaterialen enligt Europeiska kommissionen (European Commission,
2012) icke-metalliska oorganiska material (såsom kiseloxider, aluminiumoxid och titandioxid),
kolbaserade nanomaterial (såsom kimrök (eng: carbon black) och ”kolnanorör”), metaller
(t.ex. silver) och organiska makromolekyler och polymera material. Dessutom finns ett stort
antal material som är under utveckling eller används i mindre kvantiteter.
i
Nanomaterial finns i en stor mängd produkter, från vardagliga konsumentvaror till högt
specialiserade produkter inom biomedicinsk teknik och IKT (Informations och
Kommunikationsteknologi). De största tillämpningarna av nanomaterial är i däck (kimrök,
eng: carbon black) och i polymera material (huvudsakligen kiseloxid men också metaller),
inom elektronik, kosmetika och biomedicinska tillämpningar (European Commission, 2012).
Inom elektronik används nanomaterial bland annat som kiseldioxid vid tillverkning och
bariumtitanat som används för kondensatorer. Inom kosmetika används bland andra
nanomaterial kiseldioxid, titandioxid och zinkoxid. Inom biomedicin är guld och silver bland
de viktigaste nanomaterialen (European Commission, 2012). Dessutom används ett stort antal
nanomaterial i bland annat färger och bestrykningsmaterial, katalysatorer, solceller,
bränsleceller osv. Användningsområden är som synes flera och det finns unika egenskaper
som gör att nya funktioner och produkter kan utvecklas.
I termer av kvantiteter av nanomaterial så dominerar ”carbon black” (9,6 miljoner ton per år)
och kiseloxid (1,5 miljoner ton) (European Commission, 2012). Andra nanomaterial med
signifikanta mängder är aluminiumoxid (200 000 ton), bariumtitanat (20 000 ton), titan dioxid
(10 000 ton), ceriumoxid (10 000 ton) och zinkoxid (8 000 ton). Kolnanorör och kolnanofibrer
marknadsförs i storleksordningen upp till några tusen ton. Försäljning av nanosilver
uppskattas till 20 ton per år. Alla dessa uppgifter kommer från en rapport från Europeiska
kommissionen (European Commission, 2012) som i sin tur refererar till rapporter från
konsultföretag.
Framtidens nanomaterial och dess användning kan förväntas utvecklas i en mängd olika
riktningar. Exempel på intressanta områden är inom IKT och för läkemedelsdistribution. I
dessa fall kan det handla om väldigt specifika material och tillämpningar. Man kan också
tänka sig en utveckling mot mer förnybara nanomaterial exempelvis baserade på cellulosa.
Produkter med nanopartiklar på ytan som katalysatorer kan få många tillämpningar.
Kompositmaterial där nanofibrer ingår är ytterligare ett område som kan få en bred
användning. Ur miljösynpunkt kan man notera att flera av dessa tillämpningar ingår i
området miljöteknik, d.v.s. teknik som i ett livscykelperspektiv kan ge mindre miljöpåverkan, t
ex i termer av minskade koldioxidutsläpp, än traditionella produkter. Det kan handla om
energiteknik, katalysatorer och lättare material.
3
Livscykelperspektiv och metoder
För att bedöma miljöpåverkan av produkter, kemikalier och material är ett livscykelperspektiv
viktigt. Detta för att undvika att man missar viktiga aspekter eller väljer lösningar som innebär
att man flyttar miljöproblem från en livscykelfas till en annan, eller från en plats eller
tidsperiod till en annan, eller minskar ett hälso eller miljöproblem samtidigt som man skapar
ett nytt.
I den här rapporten används orden kemikalie, substans och ämne som synonymer. I
kemikalielagstiftningen definieras en vara som ”ett föremål som under produktion får en
särskild form, yta eller design, vilket i större utsträckning än dess kemiska sammansättning
bestämmer dess funktion” (se t.ex. Kemikalieinspektionen, 2011). Ordet produkt används i
den här rapporten såsom det används i samband med livscykelanalyser (se nedan) så att det
omfattar både varor, kemiska produkter och tjänster.
ii
Ett livscykelperspektiv kan användas för både produkter, kemikalier och material. Livscykeln
kan dock se lite olika ut beroende på vad det är man studerar. För kemikalier startar
livscykeln antingen vid tillverkning, eller om det är ämne som finns naturligt, vid utvinning
(Figur 1). Kemikalien kan användas i flera olika produkter. Varje produkt kan sedan genomgå
tillverkning, användning, avfallshantering och eventuell återvinning. I varje fas kan utsläpp av
kemikalien ske.
Figur 1. Livscykelperspektiv för en substans som används i flera olika produkter.
För en produkt startar livscykeln vid utvinning av de råvaror som behövs för tillverkning och
användning av produkten. I livscykeln ingår sedan tillverkning av produkten och andra varor
och tjänster som behövs i produktens livscykel, användning av produkten och
avfallshantering (Figur 2).
Figur 2. Livscykelperspektiv för en produkt.
iii
De olika livscykelperspektiven som beskrivs i figur 1 och 2 är också kopplade till olika
metoder att bedöma miljö- och hälsoaspekter av olika system. Livscykeln i Figur 1 som berör
substanser är kopplad till Substansflödesanalyser (SFA) och Riskbedömningar i
livscykelperspektiv. I substansflödesanalyser studerar man en substans från att ämnet
uppstår (antingen genom produktion eller utvinning). Sedan följer man flödet av substansen i
samhället, hur och var den används och var ämnet emitteras till omgivningen (van der Voet,
2002). Med hjälp av substansflödesanalyser kan man identifiera dataluckor, alltså brist på
information om emissioner. Förutom emissioner och dataluckor så kan även sänkor
identifieras. Sänkor kan vara permanenta genom att ämnet förstörs eller tillfälliga. Ett
exempel på en permanent sänka kan vara förbränning av organiska ämnen då ämnet förstörs.
Ett exempel på en tillfällig sänka kan vara deponier där utlakningen av ett ämne kan ske
långsamt men ändå vara större än noll. Substansflödesanalyser ger alltså information om
emissioner. Däremot behandlas inte toxiska eller ekotoxiska effekter.
Riskanalyser och riskbedömningar (eng Risk Assessment, RA) är termer som används i många
olika sammanhang med lite olika mening. Riskbedömningar kopplat till kemiska substanser
syftar till att bedöma miljö och/eller hälsorisker med ett visst ämne, antingen i en specifik
exponeringssituation eller över hela substansens livscykel. Riskbedömningar kopplat till
kemiska substanser innehåller både en exponeringsanalys och en effektanalys eller en dosresponsanalys (t.ex. Grieger et al, 2012). I exponeringsanalysen ingår att göra en analys av
vilka grupper av människor eller vilka ekosystem som kan bli exponerade för substansen och i
vilka halter. I exponeringsanalysen ingår då både uppgifter om emissioner och om spridning
och omvandling av ämnet i miljön inklusive arbetsmiljö. I effektanalysen görs en analys av
vilka effekter olika halter kan ge upphov till. Sedan vägs resultaten från exponerings- och
effektanalysen ihop i en riskbedömning. Riskbedömningar av kemiska ämnen har bland annat
reglerats på en Europeisk nivå i samband med REACH-lagstiftningen. Riskbedömningar kan
göras i ett livscykelperspektiv, d.v.s. hänsyn tas till emissioner av ämnet i hela dess livscykel.
Livscykeln i Figur 2 är kopplad till Livscykelanalyser (eng. life cycle assessment, LCA) som
studerar den potentiella miljöpåverkan av en produkt från ”vaggan till graven”. Ordet
”produkt” ska tolkas brett så att det kan innehålla både varor och tjänster. För
livscykelanalyser finns en internationell standard (ISO, 2006 a och b). Livscykelanalyser skiljer
sig från substansflödesanalyser och riskbedömningar bland annat i att det som studeras inte
är ett kemiskt ämne, utan en funktion som en produkt, en tjänst eller ett system uppfyller
(Finnveden et al, 2009). En annan skillnad är att det man studerar inte bara är emissioner av
ett ämne, utan ett brett spektrum av potentiellt miljöstörande ämnen. Vidare behandlas flera
olika typer av miljöeffekter inklusive hälsoeffekter och resursanvändning. Ytterligare en
skillnad är att en livscykelanalys studerar potentiell miljöpåverkan snarare än total. Detta
beror bland annat på att man i en livscykelanalys (som ju har en produkt som utgångspunkt)
bara studerar en mindre del av de totala utsläppen av ett ämne, nämligen den del som hör till
den produkt (eller funktion) som man studerar i livscykelanalysen (Hauschild, 2005). I en
riskbedömning (som har ett kemiskt ämne som utgångspunkt) kan man däremot inkludera
samtliga emissioner av ämnet. Därmed finns möjligheter att uppskatta den totala eller
absoluta risken för ämnet.
De olika metoderna substansflöden, riskbedömningar i ett livscykelperspektiv och
livscykelanalyser skiljer sig alltså åt på flera olika sätt. De studerar olika typer av objekt (SFA
och RA studerar substanser och LCA produkter/funktioner). SFA och RA studerar ett ämne i
iv
taget medan LCA inkluderar flera ämnen och miljöproblem. SFA tittar bara på utsläpp av ett
ämne medan RA också studerar risker med dessa ämnen. LCA studerar potentiell
miljöpåverkan medan RA kan studera (absolut) miljöpåverkan/risk).
Fast de tre metoderna alla kan ha ett livscykelperspektiv, så har de alltså olika syften och
svarar på olika frågor. Om man är intresserad av var utsläpp av en kemikalie kan uppstå så är
substansflödesanalyser ett bra metodval. Om man är intresserad av risker av ett specifikt
ämne så är riskbedömningar det bästa valet. Om man vill studera potentiella för och
nackdelar ur ett miljöperspektiv med en specifik produkt så är livscykelanalyser det bästa
valet. Eftersom de olika metoderna är gjorda för att svara på olika frågor kan de inte lätt
ersätta varandra, utan kompletterar varandra.
Man kan också notera att de olika metoderna i viss mån bygger på varandra. Den information
om emissioner som är ett resultat av en substansflödesanalys behövs också för att göra
riskbedömningar i ett livscykelperspektiv och livscykelanalyser. För att göra riskbedömningar
behövs modeller och data för exponeringsanalysen och effektanalysen. Dessa modeller och
data kan också efter viss anpassning användas i livscykelanalyser.
Riskbedömningar har utvecklats för kemiska ämnen och en viktig fråga är då om de också
kan användas för nanomaterial. En viktig aspekt i det sammanhanget är att de toxiska
effekterna av nanomaterial inte bara beror på den kemiska sammansättningen av materialet
utan också kan bero på nanopartiklarnas storlek och form. Det innebär att när man ska
karaktärisera dem så räcker det inte med sammansättningen utan det behövs även annan
information. Det innebär också att de toxiska tester som används för kemiska ämnen kan
behöva modifieras för nanopartiklar.
Ytterligare en aspekt med nanomaterial som är speciell är att det kanske inte är
koncentrationen (mätt som massa per volym) som är den mest relevanta parametern när
toxiciteten ska bestämmas. Det har också föreslagits att antalet partiklar per volymsenhet
eller yta per volymsenhet kan vara relevanta mått för att indikera risker med nanomaterial
(Arvidsson, 2012).
På motsvarande sätt kan de modeller som används för exponeringsanalysen av kemiska
ämnen vara mindre relevanta eftersom nanopartiklar kan transporteras på andra sätt än
kemiska substanser som är upplösta. Storleken och formen på nanopartiklarana kan också
förändras vilket man kan behöva ta hänsyn till i exponeringsanalysen En slutsats är därför att
även om det ramverk som utvecklats för riskbedömningar av kemiska ämnen är relevant
också för nanopartiklar, så kan både de toxikologiska testerna och modellerna för
exponeringsanalyser behöva modifieras och vidareutvecklas (Grieger et al, 2012, Praetorius et
al, 2013).
I substansflödesanalyser beskriver man flöden i termer av massa. Eftersom de toxiska
egenskaperna hos nanopartiklar ibland kan vara mer relaterade till antalet partiklar och dess
form, snarare än massan av partiklarna kan det vara mer relevant att arbeta med
partikelflödesanalyser snarare än substansflödesanalyser (Arvidsson et al, 2011).
Livscykelanalyser kan användas också för produkter som innehåller nanomaterial (Grieger et
al, 2012). I de delar som analyserar potentiella toxiska effekter så får man dock samma
problem som i riskbedömningarna, dvs att metoderna kan behöva modifieras och
v
vidareutvecklas för att fånga de aspekter som är specifika för nanomaterial.
4
Emissioner av nanopartiklar
Det finns en bred enighet om att produktion, användning och avfallshantering av
nanomaterial också leder till utsläpp. Det finns dock mycket begränsad information om dessa
utsläpp (Gottschalk and Nowack, 2011). Utsläpp kan ske i alla faser, från produktion av
nanomaterial och de produkter de finns i, till användning och avfallshantering.
Utsläpp under produktion av nanomaterial kan ske både till luft och vatten. Sådana utsläpp är
relevanta bland annat för att uppskatta risker i arbetsmiljön. Det finns dock begränsat med
data. Vid modellering av utsläpp har man därför gjort olika antaganden. Man har antagit
emissioner upp till något eller några procent, vid ”worst-case-scenarier” något högre
(Gottschalk and Nowack, 2011). Samtidigt är det klart att vid noggrant kontrollerade
produktionsprocesser kan utsläppen vara betydligt lägre. På motsvarande sätt kan man tänka
sig utsläpp från tillverkning av produkter där nanomaterial ingår. Även här har man ibland
antagit utsläpp på någon eller några procent (Gottschalk and Nowack, 2011), men det kan
vara lägre vid kontrollerade processer och möjligen högre vid dåliga arbetsförhållanden.
För många nanomaterial kan de största riskerna för utsläpp vara i samband med
användningsfasen. Arvidsson et al (2011) har exempelvis studerat nanosilver med hjälp av
partikelflödesanalyser med fokus på användningsfasen. Detta kan ses som ett intressant
exempel på olika spridningsvägar och sänkor för nanomaterial.
Nanosilver används framför allt i textilier, i sårförband och elektronik. Emissioner kopplat till
användning av textilier uppskattas vara större än från sårförband samtidigt som det enligt
Arvidsson et al (2011) är svårt att uppskatta emissionerna kopplat till användning av
elektronik. Studier har visat att silverpartiklar kan frigöras vid tvättning av textilier. Hur mycket
beror dock bland annat på hur mycket silver som finns i textilierna och det kan variera
kraftigt. Silvret som frigörs vid tvättning hamnar i stor utsträckning i
vattenreningsanläggningar där en stor del, men inte allt, kan förväntas hamna i slammet och
resterande släppas ut med vattnet. Slammet kan sedan användas som täckningsmaterial på
deponier eller användas på jord- eller skogsmark. Från slammet kan silvret lakas ut. Om det
är på deponier kan frisättningsprocessen vara långsammare och lakvattnet kan fångas i
lakvattenreningsprocesser och då eventuellt fastna i reningsverksslam igen.
Arvidsson (2012) har analyserat några möjliga framtidsscenarier med en ökad användning av
silver i textilier, Man finner då att halterna i slam kan bli högre än riskrelaterade riktvärden
och om slammet används på jordbruksmark så kan halterna bli höga om hänsyn tas till
risknivåer för maskar (Arvidsson, 2012). Halterna beror dock bland annat på hur mycket
textilier med silver som används och också hur mycket silver som används i textilierna
(Arvidsson, 2012).
Slam kan också förbrännas. Vid förbränning kommer det mesta av silvret att hamna i
bottenaskan men även i andra askfraktioner och endast en mindre del kan förväntas
emitteras med rökgaserna (Mueller et al, 2013). De olika askorna kommer att deponeras eller
eventuellt användas som konstruktionsmaterial. I båda fallen kan man förvänta sig
långsamma utlakningsprocesser.
vi
För nanosilver som sitter i sårförband kommer en mindre del att lämna förbandet under
användningen, men det mesta finns kvar i förbandet. Både för textilier och sårförband
innebär användningen en direkt exponering av människor eftersom materialen ligger mot
huden. Använda förband hamnar till stor del i brännbara avfallsfraktioner.
Nanosilver i elektronikprodukter kommer antagligen i stor utsträckning att finnas kvar i
produkterna efter användningsfasen. Om elektronikskrotet behandlas genom återvinning
finns möjligheter att delar av silvret kan återvinnas. Det är dock väl känt att elektronikskrot
inte bara behandlas genom avancerade återvinningsprocesser utan också i viss mån genom
enklare och mer miljöfarliga processer i vissa utvecklingsländer (Robinson, 2009, Umair et al,
2013), varvid utsläpp kan ske.
För andra nanomaterial kan emissioner ske på andra sätt. Titandioxid används t.ex. i
solskyddsmedel. Då sker en direkt exponering av människor, men det sker också direkta
emissioner till akvatiska miljöer i samband med att man badar med solskyddsmedel på
kroppen (Arvidsson, 2012). Nano titandioxid kan också användas i färg och cement. Från
dessa material sker dock emissioner i en långsammare takt.
Grafen är ett nytt material som kan tänkas få många olika tillämpningar till exempel inom
elektronik och som kompositmaterial. Användningen kan därför förväntas öka. Tillgängliga
data indikerat att grafen kan ha miljöfarliga egenskaper (Arvidsson et al, 2013). Det finns
dock väldigt lite information om potentiella emissioner av grafen både till yttre miljö och
relaterat till arbetsmiljö (Arvidsson et al, 2013). Det är ett exempel på de databrister som finns
för många nanomaterial.
Dessa exempel illustrerar att utsläpp från nanomaterial kan ske på många olika sätt under
livscykeln. Det kan ske både som nanopartiklar och som substanser lösta i vatten eller luft.
Det kan ske under produktion, användning och i avfallshantering. Emissioner under
användningsfasen kan ske direkt till naturen, t.ex. genom utlakning av fasader eller från
kosmetiska produkter, eller via vattenreningsprocesser. Människor kan bli exponerade direkt,
till exempel genom hudkontakt, i arbetsmiljön eller efter att utsläpp har skett till naturen.
Avfallshantering kan ha en nyckelroll. Metaller kommer inte att förstöras under
avfallshanteringen utan flyttas mellan olika former där deponier kan vara sänkor med
långsam utlakning. Hastigheten för utlakningen kan dock bero på en mängd olika faktorer
som löslighet, sammansättning och nedbrytningshastigheten för omgivande material,
partikelstorlek o.s.v. För organiska material kan nanomaterialen destrueras under förbränning.
Återvinning av produkter kan ske på många olika sätt och leda till att kretslopp sluts, men om
det sker på dåligt kontrollerade sätt kan det leda till diffus spridning av farliga ämnen.
Eftersom kompositmaterial, som är sammansatta av många olika material, ofta är svårare att
återvinna kan en ökad användning av sådana leda till ökad förbränning och deponering.
Att nanosilver valdes som exempel ovan beror dels på att silverjoner har miljöfarliga
egenskaper, men också på att det i alla fall finns några studier tillgängliga om nanosilver.
Annars är det tydligt att det för många nanomaterial och produkter saknas information, inte
bara om användningen, utan också om vilka utsläpp som kan ske under olika livscykelfaser.
Det saknas också ofta information om i vilka former emissionerna sker. Det är av betydelse
både för exponerings- och effektanalyser om emissionerna av material sker i form av
vii
nanopartiklar, större partiklar eller om ämnet har lösts ivatten eller förångats.
5
Riskbedömningar i livscykelperspektiv
Grieger et al (2012) gör en genomgång av riskbedömningar av nanomaterial. Man
konstaterar att det finns ett antal studier som har försökt göra riskbedömningar av
nanomaterial enligt gällande protokoll. Studierna behandlar bland annat nanosilver,
titandioxid-partiklar och kolbaserade produkter som kolnanorör. Alla dessa har dock dragit
slutsatsen att på grund av brist på data och stora osäkerheter har det inte varit möjligt att
genomföra kompletta riskbedömningar för dessa nanomaterial. Resultaten måste därför
betraktas som preliminära. Bland svårigheterna finns brist på mätta exponeringsdata,
modeller för exponeringsanalyser, osäkerheter i karaktäriseringen av nanopartiklarna,
tillämpligheten av olika tester, och brist på toxikologiska och ekotoxikologiska data.
6
Livscykelanalyser av nanomaterial
I Figur 3 visas en förenklad bild av livscykeln av en produkt som innehåller nanomaterial. Den
tunnare, mörka linjen innanför den tjockare representerar nanomaterialet i produktens
livscykel och visar var emissioner av dessa kan ske.
Vid utvinning av råvaror kan miljöpåverkan uppstå bland annat på grund av energiintensiv
råvaruutvinning och associerade utsläpp, förlust av icke-förnybara råvaror och utsläpp av
toxiska ämnen. Om det handlar om förnybara råvaror så kan bland annat markanvändningen
leda till påverkan på biologisk mångfald. Under produktionsfasen kan miljöpåverkan uppstå
på grund av energiintensiva tillverkningsprocesser för nanomaterial och associerade utsläpp
och möjligen utsläpp av nanomaterial. Under användningsfasen kan utsläpp av nanomaterial
ske, men produkter med nanomaterial kan också bidra till minskad miljöpåverkan jämfört
med konventionell teknik. Under avfallshanteringen kan miljöpåverkan uppstå på grund av
utsläpp från bland annat förbränning, återvinningsprocesser och deponering, men om
material och/eller energi kan återvinnas kan det leda till minskad miljöbelastning då det kan
ersätta annan produktion.
Under det senaste decenniet har ett antal livscykelanalyser eller livscykelanalysliknande
studier gjorts på produkter som innehåller nanomaterial. Både Gavankar et al (2012) och
Hischier and Walser (2012) har nyligen publicerat översikter över gjorda studier. Sammanlagt
handlar det om ca 30 studier. Många av de publicerade studierna är dock på olika sätt
begränsade. En aspekt är att många av studierna är av typen ”vaggan till grind” där alltså
produktionsprocesser ingår, men inte användning och avfallshantering. En annan
begränsning är att många av studierna fokuserar på ett begränsat antal miljöeffekter, i första
hand energianvändning och/eller växthusgaser. Däremot är toxiska effekter sämre
behandlade. Båda dessa begränsningar är i stor utsträckning kopplade till brist på data och
modeller, både för emissioner, exponeringsanalys och effektanalys av nanomaterial. Ett
antagande som ibland görs är att potentiella effekter av nanomaterial kan modelleras som
om materialet emitteras som om det har lösts upp i vatten (och därmed inte längre finns som
nanopartiklar).
viii
Figur 3. En förenklad beskrivning av livscykeln hos produkt med nanomaterial och var emissioner kan
uppstå.
En viktig aspekt vid livscykelanalyser av nanomaterial är energiåtgång och därtill associerad
miljöpåverkan vid tillverkning av nanopartiklarna. Denna kan vara svår att uppskatta bland
annat därför att det ofta handlar om nya processer under utveckling. Det kan då vara svårt att
skala upp från olika typer av pilotanläggningar till fullskaleprocesser för tillverkning av
nanomaterial. Det kan också finnas olika tillverkningsprocesser med olika prestanda.
Energianvändningen vid tillverkning av nanomaterial kan ibland vara signfikant. Ett exempel
är tillverkning av kolnanopartiklar som kolnanorör och fullerener. Dessa är 2 till 100 gånger
mer energikrävande per kg att tillverka än t ex aluminium, även med idealiserade
produktionsmodeller (Kushnir and Sandén, 2008). Kolnanofibrer kan användas i
kompositmaterial exempelvis tillsammans med polymerer och glasfibrer. Även dessa
kompositmaterial kan vara mer energikrävande än stål att tillverka (Hischier and Walser,
2012). Betydelsen av livscykelperspektiv blir dock uppenbar om man tar hänsyn till att
kompositmaterialen kan ersätta stål i till exempel fordon och då bidra till att dessa får en
lägre vikt och därmed lägre bränsleförbrukning i användningsfasen. Sett över en bils livscykel
kan då den totala energianvändningen bli lägre med kompositer som innehåller nanomaterial
jämfört med stål, trots den högre energianvändningen i samband med tillverkningen
(Hischier and Walser, 2012). Noteras kan dock att i den analysen ingick inte avfallsledet vilket
skulle kunna påverka resultatet. Inte heller ingick att ett lättare material kanske inte leder till
lättare fordon utan att man i stället stoppar in en större motor eller mer elektronik i fordonet,
ix
så att det i slutändan inte alls blir en minskning av bränsleanvändningen. För att fånga dessa
aspekter krävs en bredare och mer fullständig livscykelanalys.
En liknande situation kan vara fallet med nya litiumbatterier som innehåller nya typer av
nanomaterial. Dessa kan vara mer energikrävande att producera. Men om de används
exempelvis i fordon, kan det leda till betydligt större energivinster (Kushnir and Sandén,
2011). Tillgängligheten av litium över tiden kan dock vara en begränsande faktor för
litiumbatterier (Vikström et al, 2013) vilket möjligen kan påverka miljöbelastningen från
produktionen.
Ett annat exempel där produktionen av nanomaterial kan vara av betydelse gäller nanosilver.
Walser et al (2011) gjorde en studie av t-tröjor, tillverkade med och utan tillsatser av biocider
i form av nanosilver eller triclosan. Studien visade att beroende på produktionsmetoden, kan
utsläpp av växthusgaser under produktionen av nanosilverpartiklar vara signifikanta för en ttröjas hela livscykel (inklusive 100 tvättar) (Walser et al, 2011).
Studien av Walser et al (2011) är också intressant eftersom den är en av få studier av
produkter som innehåller nanomaterial som försöker bedöma även ekotoxiska effekter av
dessa i ett livscykelperspektiv. Man fann i denna studie att varken silver- eller triclosanutsläpp från tvättning av t-tröjan stod för de största bidragen till hela produktens potentiella
ekotoxiska effekter i akvatisk miljö. Man räknade då med en relativt hög avskiljning av
nanosilver i vattenreningsverket. I studien ingick akvatisk ekotoxicitet, däremot inte terrester
ekotoxicitet, t.ex. efter användning av silverhaltigt reningsverksslam. Utsläpp från
gruvbrytning och gruvavfall från produktion av silver kunde däremot vara signifikanta. Annars
uppstod de största ekotoxiska utsläppen i t-tröjans livscykel från produktion av t-tröjan och
tvättning (inkluderande produktion och användning av tvättmedel och produktion av el för
tvättning) (Walser et al, 2011).
7
Om val av metoder, begränsningar och utvecklingsbehov
Enligt diskussionen i kapitel 3 så kan olika metoder användas för att belysa olika typer av
frågeställningar. Lite förenklat kan vi dela in frågeställningarna i några huvudtyper och länka
dessa till de metoder som beskrivits.
En typ av frågor handlar om var i livscykeln de största emissionerna av nanomaterial kan ske.
Dessa frågor kan i första hand besvaras av substansflödesanalyser (eller
partikelflödesanalyser). Baserat på denna information kan man sedan belysa vilka grupper av
människor (anställda eller konsumenter) som löper risk för direkt exponering och till vilka
typer av miljöer emissionerna sker (vatten, mark, luft inomhus eller utomhus).
Substansflödesanalyser kan också användas för att identifiera brist på data om utsläpp.
Baserat på denna information kan man också analysera förändringar av utsläppen från olika
typer av åtgärder för att minska risker.
För att kunna göra substans- (eller partikelflödesanalyser) krävs kunskap om hur mycket av
nanomaterialen som används i samhället och i vilka produkter. Som diskuterades ovan i
kapitel 2 så finns det ingen samlad information om användning av olika nanomaterial, vare
sig mängder eller i vilka produkter.
För att kunna göra substansflödesanalyser behövs också information om utsläpp från
x
produktion, användning och avfallshanteringen. Dessa kan ofta uttryckas som
emissionsfaktorer t.ex. från användningsfasen. För att uppskatta dessa behövs ofta mätningar
och/eller beräkningar med vars hjälp emissioner kan uppskattas. Som vi såg i avsnitt 4 saknas
idag ofta data även för potentiellt miljöfarliga nanomaterial vilket gör substans- (och
partikelflödesanalyser) svåra att utföra.
En andra typ av frågor handlar om risker med användning av nanomaterial. Det kan handla
om att bedöma hur stora riskerna är med användning av ett specifikt nanomaterial, eller för
att kunna bedöma vilka de största riskerna är med ett nanomaterial i ett livscykelperspektiv.
För denna typ av frågor är riskbedömningar i ett livscykelperspektiv tänkta att användas.
Som framgick ovan i kapitel 5 finns det idag stora svårigheter att göra kompletta
riskbedömningar. Det handlar både om brist på data och brist på metoder (Gottschalk and
Nowack, 2011, Grieger et al, 2012, Praetorius et al, 2013, Savolainen et al, 2010). Dels handlar
det om uppgifter om hur och hur mycket nanomaterial som används och dels om emissioner
av nanomaterial i olika exponeringssituationer. Men det behövs också vidareutveckling av
metoder för exponeringsanalyser liksom de toxiska och ekotoxiska analyserna. Vid utveckling
av exponeringsanalyser är det också viktigt att beakta olika situationer såsom arbetsmiljö,
användning av produkter och efter utsläpp till vatten, luft och mark.
Svårigheterna att göra riskbedömningar i livscykelperspektiv innebär att även om
riskbedömningar utvecklas för att besvara frågor om risker som diskuterades ovan, så är det i
praktiken svårt att använda dem för det syftet idag. Svårigheterna att göra riskbedömningar i
ett livscykelperspektiv innebär också att även om ett nanomaterial kan leda till allvarliga
miljöproblem, så kan det vara svårt att visa det i en riskbedömning. Detta illustrerar att för att
få en säker användning av nanomaterial så kan man inte bara förlita sig på riskbedömningar
som beslutsunderlag. Det kräver mycket data och tar tid. Ett riskparadigm där ett stort antal
nanomaterial ska genomgå riskbedömningar blir därför dyrt och ineffektivt. Det behöver
också utvecklas andra metoder som kan användas som beslutsunderlag, metoder som kan
använda data och metoder som är mer lättillgängliga. Förutom att utveckla metoder och data
för riskbedömningar så behöver det därför också utvecklas metoder som kan användas i
stället för riskbedömningar vid reglering av nanomaterial. En parallell kan göras till
kemikaliområdet där Miljömålsberedningen föreslog att ska kunna behandla och pröva
grupper av ämnen utan att varje enskilt ämne genomgick en riskbedömning
(Miljömålsberedningen, 2012). Det borde också kunna vara intressant även för nanomaterial.
En tredje grupp av frågor handlar om att identifiera potentiella miljöproblem i ett
livscykelperspektiv. För dessa frågor kan både substansflödesanalyser, riskbedömningar och
livscykelanalyser vara användbara, under förutsättning att data och metoder finns
tillgängliga. Man kan dock notera att de olika metoderna har olika ansatser och därmed
möjlighet att identifiera olika typer av miljöproblem. Med substansflödesanalyser kan viktiga
emissionspunkter i nanopartiklarnas livscykel identifieras. Med riskbedömningar kan viktiga
risker i hanteringen av nanomaterial bedömas. Livscykelanalyser kan även bidra till att
identifiera andra miljöeffekter än de som förknippas med utsläpp av det specifika
nanomaterialet. Livscykelanalyser kan också utnyttjas för att identifiera de faser i livscykeln
där viktiga naturresurser används, där utsläpp av växthusgaser sker, och där andra potentiella
miljöproblem kan uppstå.
xi
Nanomaterial kan öppna upp nya möjligheter bland annat genom att man kan producera nya
och lättare material, och genom användning i energi och miljötekniska sammanhang. Men
användning av produkter med nanomaterial kan också leda till andra typer av miljöproblem.
En fjärde grupp av frågor kan därför vara att identifiera potentiella för- och nackdelar med
olika alternativa produkter, med eller utan nanomaterial, med avseende på olika miljöfrågor i
ett livscykelperspektiv. För denna typ av frågor kan livscykelanalyser användas för att visa på
möjligheter men också begränsningar med nanomaterial.
I dagsläget begränsas möjligheten att fullt använda livscykelanalyser på produkter
innehållande nanomaterial av brist på data för nanomaterialen (Gavankar et al, 2012, Hischier
and Walser, 2012). Detta gäller till exempel data för energianvändning och emissioner från
produktion av nanomaterial. Det gäller också brist på data om emissioner av nanomaterial
som diskuterades ovan i samband med SFA och riskbedömningar liksom metoder och data
för miljöpåverkansbedömningen av nanomaterial. Även för avfallshanteringen finns ofta brist
på data hur produkter med nanomaterial kan hanteras och vad som händer med olika
nanomaterial vid exempelvis deponerings och återvinningsprocesser. Bland annat dessa
metodbegränsningar innebär dock att det sällan eller aldrig är möjligt att dra bestämda
slutsatser om vilken produkt som är föredra. Rent generellt kan livscykelanalyser sällan
besvara frågor av typen ”Är produkt A bättre än produkt B ur miljösynpunkt?” och detta
gäller även produkter med nanomaterial. Mer specifika frågor av typen, ”kan den ökade
energianvändningen under produktionsfasen av produkt A uppvägas av energibesparingar i
användningsfasen jämfört med produkt B? är ofta mer lämpade för en LCA (Finnveden, 2000).
En jämförelse mellan de två studierna av Arvidsson et al (2011) och Walser et al (2011) som
diskuterades i kapitel 4 och 6 och som båda berör nanosilver illustrerar hur SFA och LCA kan
användas, vilka typer av resultat man kan få och hur de kan komplettera varandra. Studien av
Arvidsson visar bland annat hur ackumulering i jordbruksmark kan vara problematisk, en
aspekt som är svår att fånga med en LCA som inte ser hela användningen av ett ämne utan
bara den del som är associerad med en produkt, i studien av Walser et al (2011) en t-tröja. En
LCA kan å andra sidan fånga upp andra aspekter såsom utsläpp av andra toxiska ämnen och
andra miljöproblem, exempelvis klimatpåverkan från produktion av nanosilver, vilka inte alls
studeras av en SFA.
8
Pågående forskning
Utvecklingen av nanomaterial är snabb. Det har också skett en utveckling av metoder och
data för olika typer av miljö- och riskbedömningar inom området. Det är signifikativt att de
flesta referenser till denna rapport är från de allra senaste åren. Inte minst genom flera EUprojekt har kunskapsområdet utvecklats. Flera av de studier som redovisas kortfattat här är
från pågående eller nyss avslutade EU-projekt. Exempel på sådana EU-projekt av relevans för
denna rapport är Nanosustain och Prosuite som båda innehåller metodikutveckling för LCA
och riskanalyser av nanomaterial. Projektet Nanopolytox berör några grupper av
nanomaterial som används i polymerer och Nanohouse berör ytbehandlingsprodukter med
nanomaterial. Projektet Nanovalid berör metoder för riskbedömningar och Licara metoder
för LCA. Mer information om dessa och andra projekt finns i Lazarevic and Finnveden (2013)
och på hemsidor med i de flesta fall adressen www.projektnamn.eu.
Inom Sverige kan bland annat nämnas att Mistra kommer att starta ett forskningsprogram
xii
om nanomaterial under 2013. Inriktningen på detta är dock inte bestämt när detta skrivs.
Genom de forskningsinsatser som nu pågår kommer kunskapsläget att förbättras under de
närmaste åren. Man kan dock förvänta sig att många av de kunskapsluckor och
utvecklingsbehov som nämnts ovan kommer att bestå. Detta bland annat därför att flera av
forskningsprogrammen i första hand berör ett begränsat antal nanomaterial samtidigt som
antalet nanomaterial är stort och det dessutom utvecklas nya. Även tillämpningar inom t.ex.
biomedicin och IKT kan förväntas växa. Den forskning kring risker som pågår ger också nya
frågeställningar. Det finns därför ett starkt behov av forskning och kunskapsuppbyggnad
inom området livscykelaspekter av nanomaterial.
9
Rekommendationer
För att kunna säkerställa en säker hantering av nanomaterial och för att kunna identifiera
möjligheter i ett livscykelperspektiv krävs bättre data och analysmetoder. Nedan identifieras
några vägar framåt:
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Bättre information om användning av nanomaterial. För att kunna bedöma risker
behövs information om vilka mängder samhället använder, i vilka tillämpningar och i
vilka former.
Bättre information om emissioner. För att kunna bedöma risker behövs information
om var emissioner sker. Förenklade substansflödesanalyser behöver därför utföras på
nanomaterial. Metoder för detta behöver tas fram där rimliga worst-case-antaganden
kan göras för att bedöma om fördjupade analyser behöver göras. Den som sätter ett
material på marknaden bör kunna beskriva hur den kommer att destrueras alternativt
emitteras till naturen.
Fördjupade substansflödesanalyser i vissa fall. Dessa fall kan väljas av flera olika skäl:
miljömässigt problematiska nanomaterial, nanomaterial som används i stora
mängder, eller nanomaterial som kan anses vara representativa för större grupper och
därmed kan användas för att utveckla och verifiera de förenklade modellerna.
Mätningar. Substansflödesanalyser bygger på att det finns data tillgängliga som i sin
tur behöver komma från faktiska mätningar eller modellberäkningar, som i sin tur
behöver bygga på mätningar. Exempel på viktiga situationer där faktiska mätningar
behövs är för exponering i arbetsmiljö, exponering av konsumenter, flöden i
vattenreningsanläggningar, flöden i samband med återvinningsprocesser och annan
avfallshantering.
Metoder för karaktärisering av nanopartiklar. Eftersom egenskaper hos nanomaterial
kan förändras med partiklarnas form och storlek behöver de karaktäriseras på sätt
som är relevanta för emissionsmätningar, exponeringsanalyser och toxiska effekter.
Toxiska och ekotoxiska dos-responsdata behöver tas fram.
Modeller för exponeringsanalyser behöver vidareutvecklas och anpassas för
nanopartiklar.
Metoder för miljöpåverkansbedömningen i livscykelanalyser behöver vidareutvecklas
och anpassas för nanopartiklar. I takt med att metoder för riskbedömningar av
nanopartiklar utvecklas behöver metodiken för livscykelanalyser följa efter och
anpassas.
Livscykelanalysdata för nanomaterial. Livscykelanalyser är starkt beroende av
databaser och dessa har utvecklats under det senaste decenniet för traditionella
xiii
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




material och tillverkningsprocesser. Det finns dock stora brister avseende
nanomaterial. Livscykeldata är nödvändiga för att kunna bedöma potentiella för- och
nackdelar med nanomaterial i livscykelperspektiv.
Metoder att ta fram livscykeldata för nya teknologier. Nanoteknologi är ett område
under stark utveckling. Det gäller även produktionsprocesser och miljöprestanda för
dessa.
Internationell samverkan, men med svenskt perspektiv. Mycket av de data och
metoder som behöver tas fram bör ske i internationell samverkan. Det kan dock vara
viktigt att ta fram livscykeldata för produkter som tillverkas i Sverige eftersom en del
förhållanden kan vara specifika för Sverige (t.ex. råvaror och energimix). Också andra
processer som till exempel avfallshantering kan ha specifika svenska förhållanden.
Samverkan industri, myndigheter och forskning. Mycket av de data som behöver tas
fram, behöver komma från industrin som har kunskap om tillverkningsprocesser etc.
Utveckling av metoder behöver dock ske i samverkan med forskning och
myndigheter.
Trovärdig information till användare. En säker användning förutsätter informerade
användare. Märkning och annan information behöver utformas så att användare i
företag, organisationer, myndigheter och konsumenter kan fatta egna beslut.
Undvik fastlåsning i ett riskparadigm. Fullständiga riskbedömningar kräver mycket
data och tar tid. Det är dyrt och ineffektivt om det ska genomföras på ett stort antal
nanomaterial. Man måste därför kunna fatta effektiva beslut om säker användning av
nanomaterial utan fullständiga riskbedömningar.
Undvik ett material för material-paradigm. Antalet nanomaterial kan vara stort. För att
få effektiva processer måste beslut kunna fattas utan att fullständiga data finns
tillgängligt för varje enskilt material. Beslut behöver kunna fattas för grupper av
material, eller baserat på enklare kriterier.
Resurser till forskning inom flera områden. Enligt ovan behöver det tas fram metoder
och data inom flera områden för att kunna utveckla användningen av
substansflödesanalyser, riskbedömningar och livscykelanalyser. För att detta ska ske
behöver det också finnas resurser till forskning.
10 Slutsatser
Det finns ett stort antal nanomaterial som används i ett stort antal produkter, exempelvis
icke-metalliska oorganiska material (såsom kiseloxider, aluminiumoxid och titandioxid),
kolbaserade nanomaterial (såsom kimrök (eng: carbon black) och ”kolnanorör”), metaller
(t.ex. silver) och organiska makromolekyler och polymera material. Bland tillämpningar av
nanomaterial finns i däck och i polymera material, inom elektronik, och kosmetika. Det finns
också många specialiserade tillämpningar inom energiteknik, informations- och
kommunikationsteknik och biomedicinska tillämpningar.
Det finns ingen offentlig statistik tillgänglig om vilka material som används och i vilka
produkter. Miljö- och hälsorisker är både förknippade med den kemiska sammansättningen
av materialen, men också nanopartiklarnas storlek, form och egenskaper. Nanopartiklarna
behöver därför klassas inte bara med avseende på kemisk sammansättning. Storlek och form
är dock egenskaper som kan förändras under användning och efter utsläpp vilket försvårar
bedömningar av miljö och hälsorisker.
xiv
För att bedöma miljöpåverkan av nanomaterial i livscykelperspektiv finns det tre
huvudgrupper av metoder: substansflödesanalyser med vars hjälp utsläpp av nanomaterial
över dess livscykel kan analyseras, riskbedömningar i livscykelperspektiv med vars hjälp risker
för människor och miljö med användning av nanomaterial kan bedömas och livscykelanalyser
med vars hjälp potentiell miljöpåverkan av en produkt som innehåller nanomaterial kan
analyseras liksom potentiella för- och nackdelar med olika produkter med och utan
nanomaterial. För alla dessa typer av metoder finns det exempel på mer eller mindre
fullständiga fallstudier.
För susbtansflödesanalyser krävs data om användning och emissioner av nanomaterial.
Enstaka fallstudier, t.ex. för silver, pekar på att det finns risker att riskrelaterade riktvärden
överskrids. Det finns dock stora kunskapsluckor avseende emissioner av nanomaterial under
produktion, användning och avfallshantering även för ämnen med miljöfarliga egenskaper.
För riskbedömningar behöver modeller för spridning och exponeringsanalyser för
nanomaterial utvecklas, liksom dos-respons data för toxiska effekter. Fullständiga
riskbedömningar i ett livscykelperspektiv av nanomaterial är svåra på grund av de brister i
data och metoder som finns i dagsläget.
Livscykelanalyser har gjorts på ett antal produkter innehållande nanomaterial. De är dock ofta
begränsade i det att endast ett mindre antal miljöeffekter behandlas och/eller att bara delar
av livscykeln analyserats. Produktion av nanomaterial kan ofta vara energikrävande. Dock kan
i ett livscykelperspektiv användningen av nanomaterial leda till en minskad energianvändning
som är större än den som orsakades av produktionen. Användningen av nanomaterial kan
därför innebära viktiga möjligheter.
Utvecklingen av nanomaterial är snabb. Det har också skett en utveckling av metoder och
data de senare åren och det pågår bland annat flera EU-projekt vilket kommer att förbättra
kunskapsläget. Många av de databrister och forskningsbehov som identifierats kommer dock
sannolikt att finnas kvar.
För att både kunna nå en säker användning av nanomaterial och att kunna utnyttja
nanomaterialens möjligheter i ett livscykelperspektiv krävs bättre data och analysmetoder.
Som exempel på vägar framåt kan nämnas bättre information om användning av
nanomaterial, bättre information om emissioner av nanomaterial, fördjupade
substansflödesanalyser av intressanta nanomaterial, mätningar i viktiga miljöer inklusive
arbetsmiljöer och exponering av konsumenter, utveckling av metoder för karaktärisering av
nanopartiklar, utveckling av modeller för exponeringsanalyser, framtagning av toxiska och
ekotoxiska dos-responsdata, utveckling av livscykelanalysdata för nanomaterial, internationell
samverkan med svenskt perspektiv, information till användare, utveckling av metoder som
kan komplettera riskbedömningar och resurser till forskning.
xv
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Arvidsson, R. 2012. Contributions to Emission, Exposure and Risk Assessment of
Nanomaterials. PhD Thesis, Chalmers University of Technology.
Arvidsson, R., Molander, S., Sandén, B.A., 2011. Impacts of a Silver Coated Future: Particle
Flow Analysis of Silver nanoparticles. Journal of Industrial Ecology 15, 844–854
Arvidsson, R., Molander, S., Sandén, B.A., 2013. Review of Potential Environmental and Health
Risks of the Nanomaterial Graphene. Human and Ecological Risk Assessment, 19: 873–
887.
European Commission, 2011. Commission Recommendation of 18 October 2011 on the
defition of nanomaterial (2011/696/EU). Official Journal of the European Union L275/38L2
European Commission, 2012. Commission staff working paper. Types and uses of
nanomaterials, including safety aspects SWD(2012) 288 final. Brussels.
Finnveden, G., 2000. On the Limitations of Life Cycle Assessment and Environmental Systems
Analysis Tools in General. Int. J. LCA, 5, 229-238.
Finnveden, G., Hauschild, M.Z., Ekvall, T., Guinée, J., Heijungs, R., Hellweg, S., Koehler, A.,
Pennington, D., Suh, S., 2009. Recent developments in life cycle assessment. Journal of
Environmental Management 91, 1–21.
Gavankar, S., Suh, S., Keller, A.F., 2012. Life cycle assessment at nanoscale: review and
recommendations. The International Journal of Life Cycle Assessment 17, 295–303.
Gottschalk, F., Nowack, B., 2011. The release of engineered nanomaterials to the environment.
Journal of Environmental Monitoring 13, 1145–1155.
Grieger, K.D., Laurent, A., Miseljic, M., Christensen, F., Baun, A., Olsen, S.I., 2012. Analysis of
current research addressing complementary use of life-cycle assessment and risk
assessment for engineered nanomaterials: Have lessons been learned from previous
experience with chemicals? Journal of Nanoparticle Research 14, 1– 23.
Hauschild, M.Z., 2005. Assessing environmental impacts in a life cycle perspective.
Environmental Science & Technology, 39, 81A-88A.
Hischier, R., Walser, T., 2012. Life cycle assessment of engineered nanomaterials: State of the
art and strategies to overcome existing gaps. Science of The Total Environment 425,
271–282.
ISO, 2006a. ISO 14040 International Standard. In: Environmental Management – Life Cycle
Assessment – Principles and Framework. International Organisation for Standardization,
Geneva, Switzerland.
ISO, 2006b. ISO 14044 International Standard. In: Environmental Management – Life Cycle
Assessment – Requirements and Guidelines. International Organisation for
Standardization, Geneva, Switzerland.
Kemikalieinspektionen (2011): Kemikalier I varor. Strategier och styrmedel för att misnka
riskerna med farliga ämnen I vardagen. Rapport nr 3/11. Kemikalieinspektionen.
Kushnir, D., Sandén, B.A., 2008. Energy requirements of carbon nanoparticle production.
Journal of Industrial Ecology 12, 360–375.
Lazarevic, D. and Finnveden, G. 2013. Environmental aspects of nanomaterials in a life-cycle
perspective. Avdelningen för miljöstrategisk analys, KTH, Stockholm. Under
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bearbetning. www.kth.se/abe/fms
Miljömålsberedningen, 2012. Minska riskerna med farliga ämnen. SOU 2012:38,
Mueller, N.C., Buha, J., Wang, J., Ulrich, A., Nowack, B., 2013. Modeling the flows of
engineered nanomaterials during waste handling. Environmental Science: Processes &
Impacts 15, 251–259.
Praetorius, A., Arvidsson, R., Molander, S., Scheringer, M. (2013): Facing complexity through
informed simplifications: A research agenda for aquatic exposure assessment of
nanoparticles. Environmental Sciences: Processes and Impacts, 15, 161-168.
Robinson, B.H. (2009): E-waste: An assessment of global production and environmental
impacts. Science of the Total Environment, 408, 183-191.
Savolainen, K., Alenius, H., Norrpa, H., Pylkkänen, L., Tuomi, T. and Kasper, G. (2010) : Risk
assessment of engineered nanomaterials and nanotechnologies – A review. Toxicology,
269, 92-104.
Umair, S., Björklund, A. and Ekener Petersen, E. (2013): Social Life Cycle Inventory and Impact
Assessment of Informal Recycling of Electronic ICT Waste in Pakistan. In Hilty, L.,
Aebischer, E., Andersson, G., Lohmann, W.: Proceedings of the First International
Conference on Information and Communication Technologies for Sustainability ETH
Zurich, February 14-16, 2013, 52-58. ETH Zurich, University of Zurich and Empa, Swiss
Federal Laboratories for Materials Science and Technology
Van der Voet, E., 2002. Substance flow analysis methodology, in: Ayres, R.U., Ayres, L.W. (Eds),
A Handbook of Industrial Ecology. Edward Elgar, Cheltenham, UK.
Walser, T., Demou, E., Lang, D.J., Hellweg, S., 2011. Prospective environmental life cycle
assessment of nanosilver T-shirts. Environmental Science & Technology 45, 4570–4578.
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xvii
CONTENTS
ABBREVIATIONS ........................................................................................................................................ II
LIST OF FIGURES ....................................................................................................................................... III
LIST OF TABLES ......................................................................................................................................... III
1 INTRODUCTION ................................................................................................................................... 1
1.1
Background ...............................................................................................................................................................1
1.2
Overview of this study ..........................................................................................................................................1
2 NANOMATERIALS AND NANOTECHNOLOGY ................................................................................. 3
2.1
Defining nanomaterials and nanotechnology.............................................................................................3
2.1.1
Nanomaterials ...............................................................................................................................................3
2.1.2
Nanotechnology ...........................................................................................................................................4
2.2
Nanomaterials ..........................................................................................................................................................5
2.3
Applications ..............................................................................................................................................................8
2.1
Potential to contribute to sustainability and unintended consequences ........................................8
3 METHODS FOR INVESTIGATING NANOMATERIALS FROM LIFE CYCLE PERSPECTIVE ........... 11
3.1
Life cycle assessment ......................................................................................................................................... 12
3.2
Risk assessment .................................................................................................................................................... 15
3.3
Substance and particle flow analysis ........................................................................................................... 17
4 LIFE CYCLE ASSESSMENT OF NANOMATERIALS ........................................................................... 18
4.1
Research applying life cycle assessment to nanomaterials ................................................................ 18
4.1.1
Current research in the EU and OECD ............................................................................................... 18
4.1.2
Literature review ........................................................................................................................................ 19
4.1.3
Meta-analyses ............................................................................................................................................. 21
4.1.4
Results from selected case studies ..................................................................................................... 26
4.2
Obstacles to and strategies for the application of LCA to nanomaterials .................................... 32
4.2.1
Goal and scope definition ...................................................................................................................... 32
4.2.2
Life cycle inventory analysis (LCI) ........................................................................................................ 34
4.2.3
Life cycle impact assessment (LCIA) ................................................................................................... 37
5 RISK ASSESSMENT OF NANOMATERIALS ...................................................................................... 41
5.1
Risk assessment .................................................................................................................................................... 41
5.2
The complementarity of RA and LCA .......................................................................................................... 41
5.2.1
Life cycle based risk assessment ......................................................................................................... 42
5.2.2
Risk assessment complemented by life cycle assessment ........................................................ 42
5.2.3
A Stream lined approach ........................................................................................................................ 42
6 SUBSTANCE FLOW ANALYSIS OF NANOMATERIALS................................................................... 44
6.1
Research applying SFA and PFA to nanomaterials ................................................................................ 44
6.1.1
Literature review ........................................................................................................................................ 44
6.1.2
Results from selected case studies ..................................................................................................... 46
6.2
Potential life cycle release and exposure of nanomaterials ................................................................ 49
6.2.1
Production of nanomaterials and manufacture of nanoproducts ......................................... 49
6.2.2
Use phase ..................................................................................................................................................... 50
6.2.3
End-of-life phase ....................................................................................................................................... 51
7 COMMUNICATION OF A LIFE CYCLE APPROACH TO NANOMATERIALS ................................. 53
8 RECOMENDATIONS ........................................................................................................................... 54
9 CONCLUSIONS .................................................................................................................................... 56
10 REFERENCES ........................................................................................................................................ 57
APPENDIX A ............................................................................................................................................. 65
APPENDIX B ............................................................................................................................................. 69
i
ABBREVIATIONS
CED
CNF
CNT
EC
ENM
ESA
EU
GWP
ISO
LCA
LCC
LCI
LCIA
MFA
MWCNT
OECD
NP
SFA
SWCNT
PFA
UFP
Cumulative Energy Demand
Carbon Nanofibre
Carbon Nanotubes
European Commission
Engineered Nanomaterial
Environmental Systems Analysis
European Union
Global Warming Potential
International Organisation for Standardisation
Life Cycle Assessment
Life Cycle Costing
Life Cycle Inventory
Life Cycle Impact Assessment
Material Flow Analysis
Multi-wall Carbon Nanotube
Organisation for Economic Co-operation and Development
Nanoparticle
Substance Flow Analysis
Single-wall Carbon Nanotube
Particle Flow Analysis
Ultra-Fine Particle
ii
LIST OF FIGURES
Figure 1: Categorisation framework for nanomaterials ............................................................................ 5
Figure 2: Environmental systems analysis tools and their focus ......................................................... 11
Figure 3: Life cycle of a product system......................................................................................................... 12
Figure 4: Cycles for ENMs determined by the life cycles of nanoproducts ..................................... 14
Figure 5: Comparison of how RA and LCA perceive the term ‘life cycle’ ......................................... 16
Figure 6: Substance flow analysis model ...................................................................................................... 17
Figure 7: LCIA midpoint indicators for vapour-grown carbon nanotubes compared to
aluminium, steel and polypropylene .............................................................................................................. 27
Figure 8: CED of polymer nanocomposites that provide equal stiffness to a steel component
....................................................................................................................................................................................... 28
Figure 9: Difference in CED of CNF reinforced PNCs compared to steel ......................................... 29
Figure 10: Cradle-to-grave climate footprint of biocidal T-shirts and a regular T-shirt ............. 30
Figure 11: Comparison of the freshwater toxicity for the life cycle of one T-shirt ....................... 31
Figure 12: Flow chart recommending the nanomaterial assessment path depending on the
availability of data ................................................................................................................................................. 39
Figure 13: Flows of ENMs during waste disposal shown as a % of the total flow that enters the
incineration/landfill system ............................................................................................................................... 48
Figure 14: Life cycle thinking and nanomaterials ....................................................................................... 53
LIST OF TABLES
Table 1: Nanomaterials on the EU market ..................................................................................................... 7
Table 2: Applications of nanomaterials in different markets .................................................................. 9
Table 3: Environmental advantages in products for different nanotechnology sectors ............ 10
Table 4: Potential benefits and impacts of the use of nanomaterials ............................................... 10
Table 5: LCA studies of nanomaterials . ......................................................................................................... 19
Table 6: Summary of studies applying LCA studies to ENMs ................................................................ 23
Table 7: Cradle-to-gate energy requirement for various methods of CNT and CNF synthesis
....................................................................................................................................................................................... 25
Table 8: Nanomaterials with a high potential for future industrial applications ........................... 37
Table 9: Outcomes, strengths and weaknesses of LCA and RA ........................................................... 41
Table 10: Proposed Stepwise approach to LCT combined with RA ................................................... 43
Table 11: Case studies applying substance flow analysis to nanomateirals ................................... 45
Table 12: Current in-flow, stocks and emissions during the use phase for nanosilver
applications in wound dressings, textiles, and electronic circuitry ..................................................... 46
Table 13: Current in-flow, stocks and emissions during the use phase for titanium dioxide
nanoparticle applications in paint, sunscreen, and self-cleaning cement ....................................... 47
Table 14: Recovery of ENMs from PA and PP composites ..................................................................... 51
iii
1 INTRODUCTION
1.1 Background
Nanotechnology and nanomaterials are increasingly seen for their potential to provide
benefits to many areas of society. Consequentially, current and potential applications of
nanomaterials are attracting increasing investments from businesses and governments
worldwide (Royal Society 2004).
Although still an emerging technology, nanotechnology has been labelled a key enabling
technology, and applicable in almost all technological sectors (European Commission 2009a,
2004). There are high expectations as to the positive contribution nanotechnology can make
to sustainable development. It has been suggested that nanotechnology has the potential to
play a key role in addressing the UN’s Millennium Devilment Goals (Salamanca-Buentello et
al., 2005; UNESCO, 2006), and it may increase environmental sustainability via energy
technologies, water technologies, chemistry and green chemistry (Fleischer and Grunwald
2008).
However, the history of technology shows the potentially harmful unintended consequences
of
technologies
(Tenner
2001)
(e.g.,
dichlorodiphenyltrichloroethane
(DDT),
chlorofluorocarbons and asbestos). As such, Maynard (2011, 31) suggests “It makes sense to
assume that nanomaterials come with unanticipated risks”. Consequentially, as the pace of
nanomaterial research, development and production has increased, so has the concern of the
potential risk to health and the environment caused by the ubiquity of these materials.
Although the development of methods to measure and test nanomaterials has progressed
significantly, there remains significant knowledge and data gaps. This results in increased
uncertainty when assessing the potential risk of nanomaterials throughout their life cycle.
1.2 Overview of this study
In September 2012, the Swedish government released a Committee Directive to produce "A
national action plan for the safe use and handling of nanomaterials" (Dir. 2012:89). The
purpose of this action plan is that “... Sweden, in various ways, should exploit nanomaterial’s
possibilities to meet economic, medical, technical and environmental challenges, whilst
taking into account their health and environmental risks and their minimization”
(Miljödepartementet 2012, 1). The intention of this action plan is to ensure that knowledge
concerning nanomaterials being developed, coordinated and disseminated.
The Committee Directive highlights the importance of a life cycle perspective, stating under
the heading “A life cycle perspective”:
“Faced with the government's standpoint on issues of importance to the development
and use of nanomaterials at a national and international level, the availability of a
comprehensive and broad basis that takes into account both possibilities with
nanomaterials and their health and environmental risk from a lifecycle perspective is
very valuable. An important starting point for such a health and environmental risk
analysis must therefore be to review nanomaterials from a lifecycle perspective, which
also includes the disposal and recycling of products containing nanomaterials. The
1
investigator will, if necessary, suggest measures that give the government a good
basis for taking a position." (Miljödepartementet 2012, 6)
In this context, this study has reviewed the current state of knowledge on the environmental
aspects of nanomaterials in a life cycle perspective. The remit of this study was to:
- clarify the types of models and methods that would be best suited to highlight issues
relate to the safe use, safe to both human health and the environment, of
nanomaterials from a life cycle perspective;
- summarize the results of current life cycle research and difficulties, such as knowledge
gaps and the lack of information sources specific to nanomaterials;
- identify on-going research and other initiatives in Sweden, the European Union and
internationally, which focus on the development of methodologies and data
collection in order to illustrate the potential life cycle impacts of nanomaterials;
- propose priorities, from a Swedish perspective, on what can be done with the current
state of knowledge, and work which should be given priority in the short and long
term, for Sweden to achieve the level of knowledge required to understand risks and
opportunities of nanomaterials and nano-products;
- provide suggestions for images to pedagogical explain the importance of the life
cycle perspective in the Government's continuing work in the field of nanomaterials.
2
2 NANOMATERIALS AND NANOTECHNOLOGY
2.1 Defining nanomaterials and nanotechnology
2.1.1 Nanomaterials
A nanometre (nm) is one billionth of a metre. To place this in context, a human hair is
approximately 80,000 nm in width, a red blood cell is approximately 7,000 nm wide, and a
water molecule is almost 0.3 nm across (Royal Society 2004).
Broadly speaking, the term ‘nanomaterial’ refers to material with internal structures and/or
external dimensions within the nanoscale (Lövestam et al., 2010, p. 6). The nanoscale has
been reported to be between 1-100nm (ISO 2008; British Standards Institution 2007), 0.1100nm (Royal Society 2004), less than 100nm (O’Brien and Cummins 2010) or less than 500
nm (Handy et al., 2008).
Lövestam et al. (2010) note that there is a general consensus that the definition of
nanotechnology term should be pursued at a European or Global level. Hence, various
international organisations and committees such as the International Organization for
Standardization (ISO), the Organisation for Economic Co-operation and Development
(OECD), the EU Scientific Committee on Emerging and Newly Identified Health Risks
(SCENIHR), the EU Scientific Committee on Consumer Products (SCCP), and governmental
institutions at the national level, have proposed definitions of nanomaterials (see Lövestam et
al. (2010) for a detailed summary of these definitions). Nevertheless, the definition of
nanomaterials have been the subject of intensive debate during recent years, as the term has
obvious implications for regulation and policy1 (Lövestam et al., 2010).
The definition of the term ‘nanomaterial’ as given by the ISO and the European Commission
are presented below.
International Organization for Standardization
ISO (TS 80004-1) proposes the following definition for the term nanomaterial:
“Material with any external dimension in the nanoscale or having internal structure or
surface structure in the nanoscale. Note: This generic term is inclusive of nano-object
and nanostructured material”2
European Commission
The European Commission (EC) has adopted the following recommendation for the
regulatory definition for nanomaterials which are set out in articles 2-4 of the Commission
Recommendation of 18 October 2011 on the definition of nanomaterial (2011/696/EU):
“ ‘Nanomaterial’ means a natural, incidental or manufactured material containing
particles, in an unbound state or as an aggregate or as an agglomerate and where, for
1
For instance, the EU chemicals legislation REACH (Registration, Evaluation, Authorisation and Restriction of
Chemicals) applies to chemical ‘substances’ on their own, in mixtures or in articles. Although REACH does not
specifically refer to nanomaterials, REACH addresses chemical substances in any size, shape of physical form.
Hence, the definition of a substance in REACH means that substances at the nanoscale are covered by REACH and
its provisions apply to nanomaterials.
2
Nanoscale is referred to as “Size range from approximate 1nm to 100nm
3
50 % or more of the particles in the number size distribution, one or more external
dimensions is in the size range 1 nm-100 nm.
In specific cases and where warranted by concerns for the environment, health, safety
or competitiveness the number size distribution threshold of 50 % may be replaced by
a threshold between 1 and 50 %.” (European Commission 2011)
This definition is based on scientific advice from the Scientific Committee on Emerging and
Newly Identified Health Risks (SCENIHR 2010) and the Joint Research Centre (Lövestam et al.,
2010).
This report uses the term engineered nanomaterial (ENM), which is commonly defined as
materials designed and produced to have structural features with at least one dimension of
100 nanometres or less (Oberdörster et al. 2005).
2.1.2 Nanotechnology
Compared to the definition of the term ‘nanomaterial’, less focus has been placed on the
definition of the term ‘nanotechnology’. Lövestam et al. (2010) note that this is due to the
term only being of occasional practical use.
Nanotechnology is a broad term which encompasses all nanoscale science, research,
engineering and technology (Lloyd 2004). The European Commission (2004, 4) suggests that
“Conceptually, nanotechnology refers to science and technology at the nanoscale of atoms
and molecules, and to the scientific principles and new properties that can be understood
and mastered when operating in this domain”.
International Organization for Standardization
ISO proposes the following definition of nanotechnology:
“the application of scientific knowledge to manipulate and control matter in the
nanoscale to make use of size- and structure- dependent properties and phenomena
distinct from those associated with individual atoms or molecules or with bulk
materials.
Note: manipulate and control includes material synthesis” (ISO/DTS 80004-1)
4
2.2 Nanomaterials
Bauer et al. (2008) note that ENMs can provide a vast range of functions and have material
properties that shape a variety of products and services. ENMs are generally seen as having a
great potential for providing benefits to sectors such as pharmaceuticals, potable water and
water treatment, information and communication technologies (ICT), energy technologies,
chemistry and green chemistry (Royal Society 2004; Fleischer and Grunwald 2008). This is
largely due to the different material properties at the nanoscale, compared to materials at
larger scales.
Broadly speaking, ENMs differ from bulk materials due to two main reasons: relative surface
area and quantum effects. Firstly, as particle size decreases a greater proportion of atoms can
be found at the surface. Hence, nanoparticles have a greater surface area when compared to
larger particles. This has the consequence of changing properties such a reactivity, strength
and electrical characteristics. Secondly, quantum effects can affect the optical, electrical and
magnetic behaviour of matter at the nanoscale. (Royal Society 2004)
Various typologies have been developed to categorise nanomaterials. Foss Hansen et al.
(2007) have developed a typology based on physical shape. This includes the categorises of I)
bulk nanomaterials, II) materials that have nanostructure on the surface and III) materials that
contain nanoparticles. This last category consists of several subcategories including,
nanoparticles suspended in a solid, surface bound nanoparticles, airborne nanoparticles and
nanoparticles suspended in a liquid. This categorisation is illustrated in Figure 1.
Figure 1: Categorisation framework for nanomaterials (reproduced from Foss Hansen et al. (2007))
5
Approximately 11.5 million tonnes of nanomaterials, with a market value of roughly 20 bn€,
are produced and placed on the global market annually (European Commission 2012). Table
1 provides a list of nanomaterials currently on the European market.
There is little quantitative data on the annual production of ENMs and although estimates of
market size are perceived to be reliable, they still need to be taken with a degree of caution
(European Commission 2012). The European Commission (2012) notes that carbon black (9.6
million t/year) and synthetic amorphous silica (1.5 million t/year) dominate the ENM market.
Other ENMs produced in significant quantities include aluminium oxide (200,000 t/year),
barium titanate (15,000 t/year), titanium dioxide (10,000 t/year), cerium dioxide (10,000
t/year), zinc oxide (8,000 t/year), iron oxides (2,500-3,000 t/year), zirconium dioxide (2,5003,000 t/year), carbon nanofibres (300-350 t/year), carbon nanotubes (200-250 t/year), silver
(22 t/year) and platinum and palladium alloy (12 t/year).
6
Table 1: Nanomaterials on the EU market (Source: European Commission (2012))
Nanomaterial
Inorganic non-metallic nanomaterials
Synthetic amorphous silica (silicon dioxide) and similar substance
Titanium dioxide
Zinc oxide
Aluminium oxide
Aluminium hydroxides and aluminium oxo-hydroxides
Iron oxides: diiron trioxide (ferric oxide, hematite) and triiron tetraoxide (ferrous-ferric oxide,
magnetite)
Cerium dioxide
Zirconium dioxide
Barium titanate
Barium sulphate
Strontium titanate
Strontium carbonate
Indium tin oxide
Antimony tin oxide
Calcium carbonate
Aluminium nitride
Silicon nitride
Titanium nitride
Titanium carbonitride
Tungsten carbide
Tungsten sulphide
Metals and metal alloys
Gold
Silver
Platinum and palladium alloy
Nickel
Cobalt
Aluminium
Zinc
Manganese
Molybdenum
Tungsten
Lanthanum
Lithium
Carbon-based nanomaterials
Fullerenes
Carbon nanotubes
Carbon nanofibres
Carbon black
Graphene flakes
Nanopolymers and dendrimers
Polymer nanoparticles
Polymer nanotubes, nanowires and nanorods
Polyglycidylmethacrylate (PGMA) fibres
Nanocellulose (fibrils and crystals)
Nanostructured polymer-films
Polyacrylonitrile nanostructures (PAN)
Dendrimers
Quantum Dots
Nanoclays
7
2.3 Applications
Compared to bulk materials, nanomaterials often display different chemical, physical, and
biological properties; they behave differently even though possessing the same elemental or
molecular composition. Nanomaterials have the potential to make every-day consumer
products lighter, stronger, cleaner, less expensive, more efficient, more precise, or more
aesthetic. (Lövestam et al. 2010)
The Woodrow Wilson online nanotechnology consumer products inventory contains 1317
products3. Nanomaterials are used in a variety of product categories including health and
fitness, home and garden, automotive, food and beverage, multifunctional products,
electronics and computers, appliances and goods for children. Over 50% of products
containing nanomaterial can be found within the health and fitness sector, including
products such as cosmetics, clothing, personal care, sporting goods, sunscreen and filtration4.
(Woodrow Wilson International Center for Scholars 2011)
Table 2 details the various markets and applications of nanomaterials.
2.1 Potential to contribute to sustainability and unintended
consequences
The unique properties of nanomaterials are often associated with positive expectations in
areas such as material and energy efficiency, pollution and waste reduction and sustainable
development (Fleischer and Grunwald 2008; Bauer et al. 2008). Table 3 summarises some of
the environmental advantages of nanotechnology in various sectors.
However, environmental NGOs, such as Friends of the Earth, suggest that the
“nanotechnology industry has over-promised and under delivered. Many of the claims made
regarding nanotechnology’s environmental performance, and breakthroughs touted by
companies claiming to be near market, are not matched by reality. Worse, the energy and
environmental costs of the growing nano industry are far higher than expected.” Furthermore
that warn that “… overall, this technology will come at a huge energy and broader
environmental cost. Nanotechnology may ultimately facilitate the next wave of expansion of
the global economy, deepening our reliance on fossil fuels and existing hazardous chemicals,
while introducing a new generation of hazards.” (Illuminato and Miller 2010, 3–4)
Gavankar et al. (2012, 296) note that at the nanoscale “materials of the same chemical
composition but different particle-specific intrinsic and extrinsic factors may exhibit different
behaviour and have different impacts on the environment and on human health.” Table 4
illustrates the potential impacts of the use of nanomaterials, highlighting the need to
understand the environmental benefits and impacts of nanomaterials from a systems
perspective. Hence, the claims regarding the potential for nanomaterials to contribute to
sustainability require scrutiny.
3
th
as of the 10 of March 2011
Som et al (2010) note this data should be used with caution. For instance, Dekkers et al. (2007) note that, at least
from a Dutch perspective, it is possible that products on the market with the claim of ‘nano’ may neither contain
nanomaterials nor be produced with nanotechnology, and not all products advertise the presence of
nanomaterials in their products (as there has been no legal obligation to label products containing nanomaterials).
4
8
Table 2: Applications of nanomaterials in different markets (reproduced from Bauer et al. (2008))
Market
Application
C/P
Automotive industry
Lightweight construction
Painting (fillers, base coat, clear coat)
Catalysts
Tyres (fillers)
Sensors
Wear protection for tools and machines
Lubricant-free bearings
C
C
C
P
C
C
C
Construction materials
Thermal insulation
Flame retardants
Surface-functionalized building materials for wood, stone, tiles.
Façade coatings
Groove mortar
Surface-processed textiles
Smart clothes
Fuel cells
Solar cells
Batteries
Capacitors
Sun protection
Lipsticks
Skin creams
Tooth paste
Ceramic coatings for irons
Odors catalysts
Cleaner for glass, ceramic, floor, windows
Fillers for paint systems
Coating systems based on nanocomposites
Impregnation of papers
Switchable adhesives
Magnetic fluids
Data memory
Displays
Laser diodes
Glass fibres
Optical switches
Filters (IR-blocking)
Conductive, antistatic coatings
Drug delivery systems
Active agents
Contrast medium
Medical rapid tests
Prostheses and implants
Antimicrobial agents and coatings
Agents in cancer therapy
Package materials
Storage life sensors
Additives
Clarification of fruit juices
Ski wax
Antifogging of glasses/goggles
Antifouling coatings for ships/boats
Reinforced tennis rackets and balls
C
C
C
C
C/P
C/P
C
P
C
C/P
C/P
C
P
P
P
P
C
P
P
C
C/P
C
C
C
C
P
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
P
C
C/P
P
Engineering
Construction
Textile fabrics
Energy
Cosmetics
Household
Chemical industry
Electronic industries
Medicine
Food and drinks
Sports/outdoor
C=component, P=product.
9
Table 3: Environmental advantages in products for different nanotechnology sectors (Reproduced from
Bauer et al. (2008))
Sectors of nanotechnology
Examples products
Environmental advantages
Nano electronic
Electronic component, bioelectronic
component
Energy efficiency, speed data
processing, replacement of silicon
Nano optic
Optoelectronic component
Nano fabrication
Nano structures for electronic
components, ultra-thin layers of tools
and components,
Nanoparticles (as part) from new
materials or new composites
Higher data transfer rate,
miniaturisation
Energy efficiency, speed data
processing, longer life time
Nano chemistry, nanomaterials
Nanobiotechnlogy
Nano analytics
Bio-based micro manufacturing of
electronic components, bio sensors,
bio catalyst, cellular engine
Measuring instruments of quanta
effects
New mechanical, electrical,
magnetically active, optical
properties and therefore,
unknown material functions less
weight and volume, improvement
of properties
Medical early warning system
energy efficiency
Analysing nano structures
Table 4: Potential benefits and impacts of the use of nanomaterials
Nanomaterials and potential sustainability
benefits
Potential impacts
Nanomaterials such as aluminium oxide, cerium oxide,
zirconium oxide, perovskite, zeolites and precious
metals (i.e., palladium, platinum and rhodium) can be
used in catalytic conversion technologies in order to
reduce unburned hydrocarbons, particulate matter
and other emissions from cars and trucks.
However, this would need to offset the potential
negative environmental impacts that can occur during
mining and production. Additionally, some materials
are scarce leading to problems related to the scarcity
of rare earth metals.
Carbon nanotubes (CNTs) and aerogels can be used in
nanocomposites in automotive applications to reduce
weight and therefore increase fuel efficiency.
However, the production of CNTs is energy intensive,
which must be taken into consideration in any
sustainability assessment.
Biocides such as nanosilver (and to a lesser extent
various metal oxides) are used in a wide variety of
applications such as biocidal cleaning products,
antimicrobial agents and coating, application to
medical instrumentation and textiles. Nanosilver is an
effective and antimicrobial treatment/coating and can
reduce the application of hazardous substances (such
as chlorine bleach) for similar purposes.
However, silver is one of the most toxic metals to
aquatic organisms (Luoma 2008). The increased use of
nanosilver in consumer products, such as socks and
other textiles, to reduce odour and/or kill bacteria my
result in the increased flow of nanosilver to the
environment.
10
3 METHODS FOR INVESTIGATING NANOMATERIALS FROM
LIFE CYCLE PERSPECTIVE
Environmental systems analysis (ESA) is a subfield of systems science (see Ackoff (1973) and
Checkland (1999)) which aims at addressing environmental problems (Baumann and Tillman
2004). There are a number of ESA tools which differ in goal and scope (Finnveden and
Moberg 2005; Finnveden et al. 2009). Tools which are used to investigate the environmental
impact of products or substances include substance flow analysis (SFA), chemical risk
assessment (RA), and life cycle assessment (LCA), see Figure 2. These tools incorporate the
concept of a product or substance life cycle into their analysis.
Figure 2: Environmental systems analysis tools and their focus (adapted from Finnveden and Moberg
(2005))
In industry, the term ‘life cycle’ is generally understood as the life-span of either a material, a
chemical or a product, covering its production, use and disposal (Som et al. 2009). Seager
and Linkov (2008, 282) have noted that “It is now nearly universally accepted that the product
life cycle is the proper perspective for thinking about materials, including nanomaterials”.
However, the way the term ‘life cycle’ is used and perceived within different areas of
expertise, such as LCA and RA, leads to different interpretations (Christensen and Olsen
2004). Below, Sections 3.1, 3.2 and 3.3 briefly introduce LCA, RA and SFA, respectively, and
discuss how the ‘life cycle’ is perceived in each of these tools.
11
3.1 Life cycle assessment
LCA assesses the potential environmental impacts of a product/service system over its life
cycle. The term ‘life cycle’ includes the extraction and processing of raw materials, production,
transportation and distribution, use, and end-of-life (re-use, recycling, recovery and final
disposal) phases, see Figure 3.
LCA is an accepted and internationally standardised tool (ISO 14040 – 14044), defined as the
“compilation and evaluation of the inputs, outputs and the potential environmental impacts
of a product system throughout its life cycle” (ISO 2006a, 2). The ISO standards lay down
quality criteria for the design and execution of the LCA, as well as for the reporting of results,
data, methods, assumptions and limitations. (Guinée, 2002). Part of this quality criteria is the
need for a critical review, by a qualified expert or panel of experts, when an LCA is used to
support comparative assertions.
Figure 3: Life cycle of a product system (reproduced from UNEP (2007))
12
LCA consists of four phases: goals and scope definition, life cycle inventory analysis (LCI), life
cycle impact assessment (LCIA) and interpretation.
- Goal and scope definition: The goals and scope definition of an LCA provides a
description of the product system. According to ISO (2006b), the goal should state:
“the intended application, the reasons for carrying out the study, the intended
audience … and whether the results are intended to be used in comparative assertions
intended to be disclosed to the public” (ISO 2006b, 7).
- Life cycle inventory analysis (LCI): The LCI phase involves the compilation and
quantification of data for all inputs (such as energy, water and materials usage) and
outputs (such as air emissions, solid waste disposal, wastewater discharge) of all the
processes in product/ service system throughout its life cycle. These data are related
to the reference flow which is given by the functional unit (Hauschild 2005).
- Life cycle impact assessment (LCIA): The LCIA phase translates the LCI input and
output data into information about the system’s impact on the environment, human
health and resources (Hauschild 2005). It is aimed at evaluating the significance of
potential environmental impacts of the LCI phase (ISO 2006b). The LCIA phase
consists of several steps: selection of impact categories, category indicators and
characterisation models; classification; characterisation; normalisation; grouping; and
weighting (see ISO (2006a) for detail about individual phases). According to ISO,
mandatory elements of the LCIA phase are the selection of impact categories,
category indicators and characterisation models, classification, and characterisation.
Normalisation, grouping and weighting are optional.
- Interpretation: The interpretation phase evaluates all the LCA results according to the
defined goal and scope, which reach conclusions, explain limitations and provide
recommendations. The interpretation phase should include a sensitivity and
uncertainty analysis to qualify the results and conclusions of the study (Hauschild
2005).
It is important to establish a demarcation between LCA and life cycle thinking (LCT). LCT is a
concept that “seeks to identify possible improvements to goods and services in the form of
lower environmental impacts and reduced use of resources across all life cycle stages. … The
key aim …is to avoid burden shifting” (European Commission 2010), whereas LCA aims to
describe the potential environmental impacts of a product/service system over its life cycle.
13
As early as 2004, the Royal Society (2004, 32) suggested that the “potential benefits of
nanotechnologies should be assessed in terms of lifecycle assessment”. Furthermore,
according to Grieger et al. (2012), there is a general consensus amongst scientists,
researchers and regulatory agencies that the potential health and environmental risks of
ENMs should be evaluated over there entire life cycle.
In the context of nanotechnology, the term ‘life cycle’ can be used in reference to both ENMs
and nanoproducts (Som et al. 2009). For instance, a nanoparticle can be incorporated into
different ENMs which can then be used in different products. Hence, there may be a variety
of use and end of life phases for nanomaterials, depending upon the products in which they
are incorporated, as illustrated in Figure 4.
Figure 4: Cycles for ENMs determined by the life cycles of nanoproducts (reproduced from Som et al.
(2009))
14
3.2 Risk assessment
Although there are a multitude of definitions of risk, Renn (2008, 373) defines risk “an
uncertain consequence of an event or an activity with regard to something that humans
value” 5, the consequences of which can be either positive or negative depending upon the
values people associate with them.
Risk assessment (RA) has been the standard approach to assessing the potential risk of bulk
chemicals. RA assesses the risk to human health and the environmental of a single substance
at a particular point in a chemical’s life cycle or the total release of a substance from a
chemical’s life cycle (Grieger et al. 2012). The term ‘life cycle’ covers all downstream uses of
the chemical, from the manufacture of substance to its disposal or the preparations/articles
containing the substance (Christensen and Olsen 2004). RA is often performed to identify
whether any life-cycle stages pose a risk (Grieger et al. 2012).
The difference between the conception of ‘life cycle’ in LCA and RA is illustrated in Figure 5.
Whilst LCA assesses a range environmental impacts of a product system related to a
functional unit from the cradle-to-grave, RA assesses the health and environmental risk of a
single substance at a particular point in the substances life cycle.
More specifically, RA is “the task of identifying and exploring, preferably in quantified terms,
the types, intensities and likelihood of the (normally undesired) consequences related to a
risk”. RA consists of four steps:
- hazard identification: the mapping of a chemical’s inherent physico-chemical and
biological properties required to provide a uniform basis for the evaluation of hazard
potential.
- dose-response assessment: quantitative estimation of the chemical concentration
expected not to have an effect on human health or the structure and function of an
ecosystem’s species.
- exposure assessment: the application of generic and/or specific scenarios of exposure
pathways for a chemical, resulting in the a predicted environmental concentration
value for each scenario.
- risk characterisation: compares the exposure of each exposed population with the
appropriate derived no-effect level, compares the concentrations predicted in each
environmental sphere with the predicted no-effect level, and assesses the likelihood
and the severity of an event arising from the physico-chemical properties of the
substance.
There is a consensus that the RA framework is applicable to passive ENMs (SCENIHR 2009,
2010). However, many of the methodological steps within RA require further refinement or
development for ENMs (Grieger et al. 2012). There has been a recent call for a
complementary application of LCA and RA to ENMs (see Linkov and Seager (2011) Grieger et
al. (2012) and Shatkin (2008)). In this context, two approached to RA from a life cycle
perspective have been identified: ‘LC-based RA’ and ‘RA-complemented LCA’(Grieger et al.
2012) (See Chapter 5).
5
Original definition in Kates et al. (1985, p.21)
15
Figure 5: Comparison of how RA and LCA perceive the term ‘life cycle’ (reproduced from Grieger et al.
(2012))
16
3.3 Substance and particle flow analysis
Several authors have suggested a substance life cycle approach to assess the emissions of
ENMs (Lubick 2008; Sweet and Strohm 2006). Substance flow analysis (SFA) is a tool
sometimes applied prior to RA in order to estimate emissions (van der Voet et al. 1999).
Consequentially, SFA has become the point of departure for the development of emission
assessment methods (Arvidsson 2012).
SFA focus on the flows and stocks of materials, substances and particles of interest to society.
Its overall goal is to quantify the flows and stocks of a substance and estimate the emissions
from different life cycle stages, thus providing an input for policy relating to environmental
pollution (van der Voet 2002). The core principle SFA, is based in the mass balance principle,
derived from Lavoisier’s law of mass conservation (Lavoisier, 1789). Arvidsson (2012) notes
that such an analysis is often based on product life cycles, which includes raw material
extraction, production, use and end-of life, as illustrated in Figure 6. Flows between, and
stocks within, the life cycle stages are quantified and measured as mass per unit time (i.e.,
tonnes/year) and mass only (i.e., tonnes), respectively (Arvidsson 2012).
van der Voet (2002) suggests that SFA aims to provide relevant information for an overall
management strategy with regard to one specific substance or group of substance. Arvidsson
(2012) notes that emissions from society to the environment are of specific interest to SFA
studies since the flows of some substances are of particular environmental importance.
However, Arvidsson et al. (2011, 845) note that “there are strong indications, however, that
mass may not be a relevant indicator of flow and stock magnitude, exposure, or toxic effects
for the case of NPs”. Rather than using mass as a measure of the flows and stocks of
nanomaterials, particle flow analysis (PFA) measures the flows and stocks of particles. This
allows for relevant properties, such as particle size, to be accounted (Arvidsson et al. 2011).
Furthermore, processes that change particle number (such as agglomeration, melting of
particles, dissociation of particles into ions, and grinding) can be included into the analysis.
Figure 6: Substance flow analysis model (reproduced from Arvidsson et al. (2012)
17
4 LIFE CYCLE ASSESSMENT OF NANOMATERIALS
4.1 Research applying life cycle assessment to nanomaterials
4.1.1 Current research in the EU and OECD
European Union
At the European level, there is a significant call to study ENMs from a life cycle perspective.
For instance, the European Commission communication Towards a European Strategy for
Nanotechnology states “… R&D also needs to take into account the impacts of
nanotechnologies throughout their whole life cycle. For example, by using Life-Cycle
Assessment Tools” (European Commission 2004).
The European Commission’s Nanosciences and Nanotechnologies: An action plan for Europe
2005-2009. Second Implementation Report 2007-2009 (European Commission 2009b) notes
that from a regulatory point of view, an urgent need is the improvement, development and
validation of methods in the areas of “characterisation, exposure assessment, hazard
identification, life cycle assessment and simulation.” (European Commission 2009b, 9). The
Accompanying document to the Nanosciences and Nanotechnologies: An action plan for
Europe 2005-2009 Second Implementation Report 2007-2009 (European Commission 2009c)
suggests that there is a need to “further adjust, validate and harmonise currently available
guidelines for the life cycle assessment of nanomaterials and nanotechnology-based
products, building upon results from completed and ongoing activities. To develop hands-on
guidance for simplified LCAs for SMEs.” (European Commission 2009c, 92).
FP7 research projects which have some relationship to LCA of nanotechnology and ENMs
have been identified (see Jovanovic and Cordella (2011), OECD (2011) and the OECD
Database on Research into the Safety of Manufactured Nanomaterials6). These projects are
outlined in Appendix A. Findings from the research programme PROSUITE (Walser et al. 2012,
2011; Hischier and Walser 2012) and NanoImpactNet (Som et al. 2010) feature prominently in
Sections 4.1.2 and 4.1.3.
Organisation for Economic Co-operation and Development
Within the Organisation for Economic Co-operation and Development (OECD), two working
parties have been established: the Working Party on Nanotechnology (WPN) and the
Working Party on Manufactured Nanomaterials (WPMN).
The OECD has recently released a summary of National Activities on Life Cycle Assessment of
Nanomaterials (OECD 2011). This document has compiled information on OECD members
national activities related to LCA of nanotechnology and ENMs which have been provided by
delegations from the following countries: Austria, Finland, Germany, Korea, Poland, the
United Kingdom, United States, the European Commission, as well as from the Business and
Industry Advisory Committee to the OECD (BIAC). See OECD (2011) for a detailed summary of
these research projects.
6
http://webnet.oecd.org/NANOMATERIALS/Pagelet/Front/Default.aspx
18
4.1.2 Literature review
A comprehensive meta-analysis of the state-of-the-art of LCA research on ENMs is beyond
the scope of this report. Whilst highlighting some of the current research results, our primary
objective is to focus on the potentials and limitations of current research efforts in order to
propose further research priorities.
To this end, a non-exhaustive search of academic literature databases (Scopus, ScienceDirect)
and an internet search for publications (such as those in scientific journals, conference
proceedings, conference presentations, research reports and theses) was completed using
the following combination of keywords:
- nano + life cycle assessment
- nano + “life cycle assessment”
- nano + “life cycle”
- nano + LCA
The studies identified are highlighted in Table 5. Three meta-analyses of the LCA of ENMs
can be found in the peer-reviewed literature: Hischier and Walser (2012), Gavankar et al.
(2012) and Upadhyayula et al. (2012). Hischier and Walser (2012), Gavankar et al. (2012)
reviewed all studies applying LCA to ENMs, whilst Upadhyayula et al. (2012) specifically
focused on carbon nanotubes (CNTs) and carbon nanofibres (CNFs). The LCA studies
considered by these meta-analyses can be found in Table 5.
Table 5: LCA studies of nanomaterials.
Publications
Type
Babaizadeh and Hassan
(2013)
†‡
Bauer et al. (2008) *
J
De Figueirêdo et al. (2012)
J
J
†
Fthenakis et al. (2008) ;
†
Fthenakis et al. (2009)
Greijer et al. (2001)
C
C
†
J
Griffiths and O’Byrne (2013)
†
Grubb and Bakshi (2008) ;
†
Grubb (2010) ;
Grubb and Bakshi (2011a,
†‡
2011b)
†‡
†
Healy et al. (2008 *; 2006 );
†
Isaacs et al. (2006, 2010)
†
Joshi (2008)
J
T
C
J
Nanomaterial
Focus of Study
TiO2
Comparison of TiO2 coated class with
float glass
Ti, TiAl, Ti+TiAl
Examine implications of life cycle
thinking on nanotechnology (and
nanoproduct) evaluation; 2 case
studies
Cellulose
The comparison of two alternative
nanowhiskers
processes for the production of
cellulose nanowhiskers
Nanocrystaline-Si,
Comparison of the cumulative energy
nano CdTe, and
demand for the production of PV
nano-Ag PV systems systems using nanomaterials
Nanocrystaline dye
Identify the significant environmental
(out of nano- TiO2
aspects of nanocrystaline dye sensitive
and carbon black)
solar cell system
Multi walled carbon Identification and quantification of the
nanotubes (MWCNT) environmental impact of MWCNT
formation via catalytic chemical
vapour deposition.
TiO2
Evaluate the production processes for
TiO2
J;C
C;J
J
Life cycle phases
E M
U EOL
O O
O x
O O
O O
O O
x
x
O O
x
x
O O
O O
O O
x
x
O O
x
x
Single walled carbon Environmental assessment of SWNCT
O O
x x
nanotubes (SWCNT) production
Nanoclay (ONMT,
Comparison of nanoclay composite
O O
x x
organically modified biopolymer with biobased polymers
montmorillonite)
† Reported in Hischier and Walser (2012); ‡ Reported in Gavankar et al. (2012); * Reported in Upadhyayula et al.
(2012);
C: Conference; J: Journal; T: Thesis; B: Book Chapter; R: Report. O: Included; x: Excluded
19
Table5 (Cont.): LCA studies of nanomaterials
Publications
Type
†
Khanna et al. (2007) ;
Khanna, Zhang, et al.
†
(2008b) ;
Khanna, Bakshi, et al.
†‡
(2008a) *
‡
Köhler et al. (2008)
Nanomaterial
Focus of Study
J
B
C
CNFs
Environmental burden of CNF
synthesis
J
CNTs
Life cycle phases
E M
U EOL
O O
x x
Potential release of carbon nanotubes
x O
O O
throughout the life cycle of textiles
and lithium-ion batteries
†
Kushnir and Sandén (2008)
J
Fullerenes and CNT
Implications for industrial scale
O O
x x
‡
*
production
†‡
Lloyd and Lave (2003) ;
J
Nanoclay-reinforced Replacing auto-body panels made of
O O
x x
†
Lloyd (2004)
T
polymer composites steel with those of polymer
composites with aluminium
†‡
Lloyd et al. (2005) ;
J
Nanoscale platinum- Evaluating reduction in non-renewable O O
x x
†
Lloyd (2004)
T
group metal (PGM)
resources like PGM via greater process
particles
control offered by nanotech
Merugula et al. (2010)
C
CNTs (in reinforced
Comparison of vapour-grown carbon
O O
O O
wind turbine blades) nanofibre reinforced glass fibre epoxy
matrix and glass fibre reinforced
plastic
‡
Meyer et al. (2011)
J
Ag
Identifying the life cycle hot spots via
O O
x x
screening level LCA
Moign et al. (2010)
J
Zirconium
Comparison of spraying technologies
O O
x x
nanopowder
for the manufacture of yttria-stabilised
zirconia
†‡
Osterwalder et al. (2006)
J
Various oxide
Energy comparison of wet and dry
x O
x x
nanoparticles
synthesis methods for oxide
nanoparticle production
†‡
Roes et al. (2007)
J
Polypropylene
Compare environmental impact and
O O
O O
Nanocomposite
cost of polypropylene nanocomposite
with conventional polypropylene in
the use cases: i) packaging film, ii)
agricultural film, iii) automotive body
panel.
†
Roes et al. (2010)
J
SiO2, CaCo3, CNTs
Compared the non-renewable energy
O O
O O
WMCNTS,
use of 23 nanocomposite materials
organophilic
with 3 conventional composite
montmorillonite
materials
‡
Şengül and Theis (2011)
J
QD photovoltaics
LCA of a proposed type of
O O
x x
nanophotovoltaic, quantum dot
photovoltaic module
†
Singh et al. (2008) *;
J
CNTs
Environmental Impact Assessment
O O
x x
†
Agboola (2005)
T
(EIA), via LCA method, of two methods
for producing SWCNTs
Steinfeldt, Gleich, et al.
R
Nanoelectronics
Lighting – LEDs
x x
O x
†‡
(2004a) ;
R
Nanomaterials/nano Chemical/paintings
O O
x x
Steinfeldt, Petschow, et al.,
particles
Chemical/plastics
O O
x x
†
(2004b)
Electronics/displays
O O
x x
†
Walser et al. (2011)
J
Ag
Comparison of the environmental
O O
O O
benefits and impacts of nanosilver Tshirts with conventional T-shirts and Tshirts treated with triclosan
† Reported in Hischier and Walser (2012); ‡ Reported in Gavankar et al. (2012); * Reported in Upadhyayula et al.
(2012);
C: Conference; J: Journal; T: Thesis; B: Book Chapter; R: Report. O: Included; x: Excluded
20
4.1.3 Meta-analyses
Engineered nanomaterials
Hischier and Walser (2012) and Gavankar et al. (2012) note that whilst there is plenty of
literature promoting the application of LCA, studies applying LCA to the area of
nanotechnology are ‘scarce’. Furthermore, these studies only looked at parts of the life cycle,
with no quantitative studies addressing all life cycle phases.
ENM studies in these meta-analyses included: cadmium telluride, calcium carbonate, carbon
black, carbon nanofibres (CNFs), carbon nanotubes (CNTs), nanoclay, nanoscale platinumgroup metals, silica, silver, silicon, titanium and titanium oxide. Product systems studied
included: auto-body panels, biopolymers, coatings, electronic displays, electronic sensors,
lithium-ion batteries, photo voltaic systems, packaging and agriculture polymer films, ENM
production processes, textiles and wind turbine blades.
The general conclusions of these meta-studies can be summarised as follows:
- Proper goal and scope definition is of “crucial importance in order to get meaningful
results that take into account the different properties, especially for comparisons with
traditional materials.” (Hischier and Walser 2012, 279)
- The LCIs cannot be classified as comprehensive as they often lack ENM specific data
related to the outputs of the processes (Hischier and Walser 2012). Hischier and
Walser (2012, 279) also highlighted the “considerable variability of the (traditional)
inventory items like energy input, material input, etc., … especially concerning the
energy consumption for the production of the various engineered nanomaterials.”
Hence, populating LCI databases with ENM specific information, such as size and
shape, is of critical importance (Gavankar et al. 2012). The retention of as much nanospecific information as possible would then facilitate subsequence LCIA for ENMs
(Gavankar et al. 2012).
- Regarding LCIA, “there is a complete lack of characterization factors for release of
nanoparticles indoors and outdoors. ... Only in exceptional cases are first approaches
to examine e.g. the toxicity of the emissions to air and water reported. However, it is
not always clear if nano-specific aspects were taken into account” (Hischier and
Walser 2012, 279). A number of existing tools, such as USEtox (Rosenbaum et al.
2008), CALtox (McKone and Enoch 2002) and QSAR (Dudek et al. 2006; Puzyn et al.
2009, 2010), are available to quantitatively assess the fate, transport or toxicity of
chemicals and bulk materials (Gavankar et al. 2012). The incorporation of additional
information on ENM specific properties into these existing tools would allow the
modelling capability of ENMs behaviour and impact in the environment.
- Due to the lack of modelling techniques available for the critical, yet frequently
omitted, use and end-of-life phases, the development of protocols and models are
needed to enable a holistic assessment that takes into consideration ENM’s intrinsic
properties (Gavankar et al. 2012).
- In the absence of any empirical data, qualitative or screening LCAs should be
performed (Gavankar et al. 2012).
- LCA should be complemented with tools such as risk assessment when location
specific parameters are critical for understanding the behaviour and impact of ENMs,
as LCA may not be able to capture such context specific sensitivities (Gavankar et al.
2012).
21
Hischier and Walser (2012) and Gavankar et al. (2012) considered a diversity of ENMs and
product systems, consequentially they could not compare the result of individual LCA studies.
Instead, these studies investigated the how the LCA methodology was applied to each case;
for instance, the function units considered, the life cycle stages considered, the
environmental impact categories selected, the consideration of the ENM specific data in the
LCI and LCIA phases, and data and methodological gaps.
Hischier and Walser’s (2012) meta-analysis of the ‘Life cycle assessment of engineered
nanomaterials’ aimed to 1) provide an overview of LCA studies in the area of ENMs, and 2)
identify the shortcoming which contribute to delaying the comprehensive application of the
LCA framework to ENMs, and 3) propose strategies to overcome these shortcomings.
Although the authors noted a scarcity of studies applying the LCA approach to the area of
nanotechnology, 17 studies7 were analysed. The authors categorised the studies by how they
addressed the following issues: consideration of functional unit, consideration of system
boundaries, production systems studied, LCI and LCIA. These results are summarised in Table
6.
7
Some studies having multiple publications
22
Table 6: Summary of studies applying LCA studies to ENMs as reported in Hischier and Walser (2012)
Aspect
Functional unit
System boundaries
Life cycle phases
Production systems studies
Resource extraction
& production
Use phase
End of life
Life cycle inventory
Life cycle impact
assessment
Meta Study Results
In terms of functional unit, two groups of studies were distinguished:
- Weight based: Half the studies assessed the environmental impact of the
production of a specified quantity (usually 1 kg) of ENM
- Application/service based: The other half of the studies assessed the
environmental impact of the specific application of the ENM, for instance
1kWh of electricity output from a nano solar cell system.
In terms of life cycle phases addressed, two groups were identified:
- Cradle-to-grave studies: considered all life cycle stages, from extraction of
raw materials to the end-of-life phase. Six of the 17 studies considered all
life cycle phases.
- Cradle-to-gate studies: considered the resource phase and the production
phase. The gates of these studies were considered as either the production
site of the ENMs, or the production site of the product containing ENMs.
Eleven of the 17 studies were cradle-to-gate studies.
Three quarters of the studies compared the ENM with traditional materials.
This comparison was divided into two groups. The first considered the specific
application of the respective material and thus employed context related
2
functional unites (such as 1m of photovoltaic cell material). The other group
assessed the production of the ENM without taking into consideration any
contextual application.
All studies included the extraction and production phases.
Ten of the 17 studies included the use phase. Although there was typically not
a lot of detail reported, such as the release of ENMs.
The six studies that considered the end of life phase mostly assumed
incineration in a municipal solid waste incinerator. However, traditional
models for incineration were used which do not take into account the fate of
ENMs as a separate flow. One study, Bauer et al. (2008), qualitatively described
the potential release pathways during the end of life phase. Hence, ENMs were
not quantitatively evaluated during the end of life phase.
The majority of studies used publically available literature. Only in four out of
the 17 studies were data taken from either actual production plant (pilot and
commercial), theoretical calculations, or process simulations. All studies
included detailed information on energy use, and many studies included
information on material inputs. Whilst several studies reported emissions to
air, these emissions were for ‘conventional’ flows. Furthermore, there was
little detail on information regarding emissions to water and soil, be they
‘conventional’ or nano emissions. Only one study, Walser et al. (2011), covered
the output of ENMs.
Three studies considered were LCI or energy analysis studies (no LCIA
performed). The remaining studies often reported one or two LCIA categories.
LCIA categories linked to energy consumption such as global warming potential
(GWP) were considered by the majority of the studies. Although the release of
nanoparticles to air, water and soil are suspected of having potential impacts
on human health and the environment, only Walser et al. (2011) considered
the freshwater and seawater toxicity results for colloidal silver. Whilst several
studies reported ecotoxicity, no LCIA methods contain characterisation factors
for either the indoor or outdoor releases of nanoparticles.
23
Carbon nanotubes
Upadhyayula et al. (2012) recently conducted a review of LCA of CNTs, analysing seven
studies8. The aim of this research was to emphasise the role of LCA during the development
of CNT products in order to mitigate potential impacts to human health and ecosystems over
their life cycle.
These studies considered CNTs and CNFs9. Five studies were cradle-to-gate and two studies
were cradle-to-grave. For the cradle-to-gate studies, the functional units related to the
production of 1kg (in one case 1 g) of CNTs via alternative production technologies. Table 7
illustrates the cradle-to-gate energy consumption for the four major synthesis routes for
CNTs: electric arc discharge, laser ablation, chemical vapour deposition (CVD) and highpressure carbon monoxide (HIPCO) processes.
CNT manufacture is energy intensive due to the processes involved in the preparation of raw
materials (i.e., the need for ultrapure graphite, purification of gasses and purification of CNTs
prior to use) and the high temperature requirements for synthesis processes (Upadhyayula et
al. 2012).
Table 7 does not account for the full impact of air emissions and waste stream discharges
(Upadhyayula et al. 2012), because accurate models, and characterisation factors for human
health and ecological impact, have yet to be developed (Khanna 2009). For instance, liquid
waste from nanoproduct manufacture may potentially contain CNTs and other toxic
materials, such as heavy metals, which require treatment that has not been included in these
studies (Upadhyayula et al. 2012). Furthermore, solid waste from these manufacturing
processes can potentially lead to the generation of solid hazardous waste due to the low
recyclability of metal catalysis (Upadhyayula et al. 2012).
The energy demand for a CNT product is dependent upon: a) quantity of CNTs used in the
product, b) purity and type of CNTs needed and, c) specialised operational steps as
demanded by the CNT product manufacturing process.
Upadhyayula et al. (2012) infer that the potential environmental problems caused by CNT
products can be attributed to two factors: the energy intensive manufacturing stage and the
potential release of toxic air emissions and liquid waste discharges in the various life cycle
stages.
8
Five of these LCAs where analysed by Gavankar et al. (2012) and six were analysed by Hischier and Walser (2012)
Although the CNFs are not technical CNTs, both nanomaterials have a similar have similar production methods
with comparable impacts. (Upadhyayula and colleagues 2012).
9
24
Table 7: Cradle-to-gate energy requirement for various methods of CNT and CNF synthesis (reproduced
from Upadhyayula et al. (2012))
Synthesis
method
Arc discharge
Material inputs
Precursor Catalyst
Pure
Ni, Co, Y
graphite
Acid
Nitric
acid
Laser ablation
Pure
graphite
Ni, Co, Y
Nitric
acid
CVD (Fixedbed)
Hydrocarbons
Fe, Ni, Co, Mo
Mineral
acids
CVD (Fluidized
bed)
Methane
CVD (Floating
bed) Benzene
CVD (VGCNF)
Benzene
HIPCO &
CoMoCAT
Carbon
Monoxide
Methane
Ethylene
Benzene
Energy
(MJ/kg)
4.6E+05
3.2E+05
2.2E+05
8.7E+07
9.6E+03
7.0E+05
9.2E+05
6.3E+05
SRCY
(%)
4.5
4.5
50
-
Fe, Ni, Co, Mo on Mineral
metal oxides
acids
8.5E+02
30
Fe, Ni, Co, Mo on Mineral
metal oxides
acids
Ferrocene
Mineral
acids
4.8E+02
-
1.1E+04
8.0E+03
2.9E+03
50
50
70
Khana et al. 2008
Iron
pentacarbonyl or
Co and Mo
4.7E+05
1.6E+05
5.3E+08
8.1E+07
2.4E+07
5.8E+03
50
50
-
Gutowski et al., 2010
Healy et al., 2008
Nikolaev et al., 1999
Brownikowski et al.,
2001
Smalley et al., 2007
Kushnir & Sanden, 2008
Nitric
acid
25
2.95
2.95
References
Product characteristics
Gutowski et al., 2010
Healy et al., 2008
Kushnir & Sanden, 2008
Gutowski et al., 2010
Kushnir & Sanden,
2008Ganter et al., 2009
Gutowski et al., 2010
Healy et al., 2008
(i) Structurally superior
(ii) Low-level metal
impurities
(i) Structurally superior
(ii) Low-level metal
impurities
(i) Low structural quality
(ii) High-level metal
impurity requiring
intensive purification
Kushnir & Sanden, 2008 (iii) Assumed
purification yields up to
90%
Kushnir & Sanden, 2008
(i) Assumed purification
yields of 90%
(ii) Less stringent purity
requirements
(i) Structurally superior
(ii) High purification yields
4.1.4 Results from selected case studies
Carbon nanofibres: Khanna et al (2008a) and Khanna and Bakshi (2009)
Studies by Khanna et al. (2008a) and Khanna and Bakshi (2009) highlight the importance of
considering the function of the nanoproduct with a specified context.
Khanna et al. (2008a) evaluated the life cycle energy requirements (cumulative energy
demand) and performed an LCIA for CNF synthesis using various hydrocarbon feedstocks
and compared these results with those of traditional materials (steel, aluminium and
polypropylene). An LCI was completed for vapour-grown carbon nanofibres (VGCNF) based
upon on laboratory data and data available from literature sources.
The authors show that the cradle-to-gate energy requirements of CNFs range from 2,872
MJ/kg for benzene feedstock to 10,925 MJ/kg for methane feedstock. This energy
requirement is significantly greater when compared to conventional materials: steel 30MJ/kg,
aluminium 218 MJ/kg and polypropylene 119 MJ/kg (Khanna et al. 2008a). The LCIA results
for the midpoint indicators global warming potential, human toxicity potential, ozone layer
depletion potential, photochemical oxidation potential, freshwater aquatic ecotoxicity
potential, terrestrial ecotoxicity potential, acidification potential, acidification potential and
eutrophication potential are illustrated in Figure 7. However, the LCIA did not consider the
release and impact of nanoparticles on human and ecosystem species.
This type of comparison can be useful for identifying hot-spots of environmental impact in
the manufacture of CNFs, thus highlighting areas for improvement. Upadhyayula et al. (2012)
note the findings of LCAs of CNT production highlight the need to refine CNT manufacturing
by adapting synthesis techniques involving low temperatures, renewable feedstocks and
recycled materials as catalytic supports.
26
Figure 7: LCIA midpoint indicators for vapour-grown carbon nanotubes compared to aluminium, steel
and polypropylene (reproduced from Khanna et al. (2008a))
27
However, the direct comparison of the CED of the production of 1 kg of CNFs to the
production of 1kg of steel, aluminium or polypropylene does not reflect the actual
replacement of steel, aluminium or polypropylene (Hischier and Walser 2012). The potential
environmental impacts of specific nanoproducts need to be compared to conventional
products (i.e., products manufactured from either steel, aluminium or polypropylene) which
provide the same performance or utility (Khanna and Bakshi 2009).
In this context, Khanna and Bakshi (2009, 2079) conducted such a study, with the aim of
assessing the CED of CNF based polymer nanocomposites (PNCs) and their comparison with
steel “on a functional unit basis of a standard plate and automotive body panel”. In this study,
various CNF polymer nanocomposites (PNCs) (content varying between 0.6 to 15 vol.%) with
and without glass fibres were analysed.
Results from this study are illustrated in Figure 8. This comparison shows the dramatic
reduction in CED due to the small amount of CNFs used to provide the same mechanical
stiffness as a steel component. For example, to achieve a similar functionality (mechanical
stiffness) to 1 kg of steel, a polypropylene CNF-glass fibre matrix containing 2.3% CNFs was
necessary, resulting in a weight of 0.38 kg.
Figure 8: CED of polymer nanocomposites that provide equal stiffness to a steel component (Reproduced
from Khanna and Bakshi (2009))
28
Furthermore, using the results produced by Khanna et al. (2008a), Hischier and Walser (2012)
show the importance of considering the use phase. When the use phase is considered, the
reduced weight of the CNF reinforced PNC component leads to a lower CED when compared
to the steel component. Figure 9 highlights three types of comparisons of the CED of CNFs
and steel, highlighting the importance of both the function unit and use phase in the analysis
of ENMs. Point ① shows the CED for the production of 1 kg of CNF is almost 11 times higher
than that of 1 kg of steel (Hischier and Walser 2012). Point ② shows the considerable
reduction in the CED of the PNC component, although still higher than the steel component.
Point ② shows the lighter weight of the PNC component influences the energy use during
the use phase, and the PNC component has a lower CED than the steel component.
“Difference in the CED value (expressed in GJ/kg) when compared with 1 kg of steel; i.e. a negative value indicates
that the CED of the respective material is lower than the CED of 1 kg of steel – point ① on the level of pure
materials, point ② on the level of equally stiff material, and point ③as part of a car, driving around 280000 km”
(Hischier and Walser 2012, 276)
Figure 9: Difference in CED of CNF reinforced PNCs compared to steel (Reproduced from Hischier and
Walser (2012))
29
Nanosilver T-Shirts: Walser et al. (2011)
Walser et al. (2011) have compared the environmental impact of nanosilver T-shirts to
conventional T-shirts with and without biocidal treatment. The authors investigated the
environmental performance of two nanosilver production processes: commercialised flame
spray pyrolysis (FSP) with melt-spun incorporation of silver nanoparticles, and plasma
polymerization with silver cosputtering (PlaSpu) at the laboratory, pilot and commercial
(estimated) scales. The T-shirts were compared via the functional unit of “being dressed with
a biocidal polyester T-shirt for outdoor activities during one year in Switzerland (wearing it
once a week)” (Walser et al. 2011, 4573).
Figure 10 illustrates the life cycle CO2-equivilent emissions of a conventional T-shirt, a T-shirt
treated with 22mg of triclosac (a bicoidal treatment), a T-shirt with 47mg of nano sized silvertricalciumphosphate (nanoAg-TCP) treated by the FSP process, and a T-shirt treated with
31mg of pure nanosilver from the PlaSpu process. For the conventional T-shift, triclosan Tshirt and FSP nano sliver coated T-shirt, the largest contribution to the carbon footprint was
the use phase, which was assumed to be 100 washes. The PlaSpu process significantly
increased the carbon footprint of the T-shirt.
The production of nanosilver from the FSP process (0.21 kg of CO2-equivelnts) has no
significant influence on the CO2-equivilent emissions during over the life cycle of the T-shirt.
However, the PlaSpu process has a much greater influence on the carbon footprint of the Tshirt, even though this reduces with technological development (PlaSpu laboratory: 164.0 kg
of CO2-equivelnts, PlaSpu pilot: 15.24 kg of CO2-equivelnts, and PlaSpu commercial: 5.14 kg
of CO2-equivelnts).
Figure 10: Cradle-to-grave climate footprint of biocidal T-shirts and a regular T-shirt (100 washings)
(reproduced from Walser et al. (2011))
30
This was the only LCA study to analyse the freshwater and seawater toxicity of Nanosilver.
Compared to a conventional T-shirt, both silver and triclosan emissions are not considered
relevant when taking the whole life cycle into consideration. The silver released from washing
accounts for less than 1% of the overall freshwater toxicity of the nanosilver T-shirts. Figure
11 highlights the insignificant contribution of the release of silver over the T-shirts life cycle
compared to freshwater toxicity associated with processes over the T-shirts life cycle.
Figure 11: Comparison of the freshwater toxicity for the life cycle of one T-shirt (reproduce from Walser et
al. (2011))
31
4.2 Obstacles to and strategies for the application of LCA to
nanomaterials
4.2.1 Goal and scope definition
Hischier and Walser (2012) note that engineered ENMs may have specific functions and
material properties that provide additional gains when used as a substitute for traditional
materials. Hence, these additional functions and properties should be taken into
consideration in the scope of the LCA. Due to these special material properties, Bauer at al.
(2008, p 914) note that it “seems obvious that materials and services must be assessed in the
context of a product or a functional purpose to quantify expected benefits also with regard
to the entire life cycle.”
Obstacles
Functional unit
ISO (2006b, 9) states that a key feature of LCA, separating it from other methods such as
environmental impact assessment and risk assessment, is that it is a “relative approach based
on a functional unit”. LCA relates the inputs and outputs of a system to the function that is
provided: “This functional unit defines what is being studied. All subsequent analyses are
then relative to that functional unit, as all inputs and outputs in the LCI and consequently the
LCIA profile are related to the functional unit” (ISO 2006b, 7).
Since LCA typically compares alternative ways of delivering the same function, it is important
that the systems being compared actually provide the same function (Hauschild 2005).
Typically, more than one function is provided by one of the systems being compared. In this
case, methods such as allocation or systems expansion (see JRC (2010) for a detail description
of these methods) can be followed to ensure that the systems being compared are equal.
Several authors note that the choice of functional unit is an especially important
consideration - a prerequisite - in order to perform a meaningful LCA of ENMs (Klöpffer et al.
2007; Hischier and Walser 2012; Bauer et al. 2008). The definition of the functional unit
becomes more difficult when dealing with ENMs due to the plethora of functions and
material properties which can be achieved at the nanoscale.
As demonstrated in section 4.3.2, basing a functional unit on weight alone would only make
sense if one is comparing alternative production processes to produce, for instance, one
tonne of the same ENM with the same functionality. Since the potential sustainability benefits
of ENMs are related to their interactions with other materials or components, once the goal
of the study goes beyond the production of a specific ENM a functional unit based on weight
is inappropriate (Hischier and Walser 2012).
When the goal of the study involves the use of nanoproducts the functional unit should be
defined in relation to the service provided by the product (the product performance during
the use phase) (Hischier and Walser 2012). However, Klöpffer et al., (2007) note that
nanoproducts fulfil functions that are quite new, leading to a difficulty to specify functional
alternatives.
32
System boundaries
The system boundaries determine what processes should be included in an LCA. ISO (2006b,
12) states that “Ideally, the product system should be modelled in such a manner that inputs
and outputs at its boundary are elementary flows.” Decisions regarding what processes
should be included or excluded from a study will ultimately have an influence on the result of
the study. Hence, it is important that the models, assumptions and choices made should be
transparent.
Klöpffer et al. (2007) stress that LCA studies of ENMs and nanoproducts should address all life
cycle stages. However, in their analysis of current research addressing complementary use of
life-cycle assessment and risk assessment for ENMs, Grieger et al. (2012, 6) note that few
“studies have encompassed the full life-cycle, and most of them focused on a cradle-to-gate
study or on a specific LC stage. … Moreover, the majority of these have relied upon generic
life-cycle impact databases or general literature in formulating the inventories and impact
assessment criteria (i.e., excluding potential toxicological impacts of NMs).” Indeed, Gavankar
et al. (2012) have noted that no LCAs of ENMs are compliant with the ISO standards as none
of them have covered the complete life cycle of an ENM or product.
Use phase
Bauer et al. (2008, p. 914) note that a dissipative use of ENMs is characteristic for a large
share of products, whereby the ENM enters the environment during its use. To this end,
Gottschalk and Nowack (2011) have demonstrated that initial analytical and experimental
studies have shown evidence for the release of ENMs from products such as textiles and
paints.
In their meta-analysis, Hischier and Walser (2012, 274) note that in studies which included the
use phase there was limited information regarding how ENMs were considered. The authors
noted that this is “an astonishing fact when one keeps in mind the various advantages, e.g. in
view of the sustainability of ENMs highlighted in various studies about this new technology”.
End of life
A small group of nanoproducts are designed for a longer life, where the ENMs will enter the
end of life phase of the product life cycle (Bauer et al. 2008). Bauer at al. (2008) note that little
emphasis has been given to the end-of-life phase, which has often been disregarded due to
data gaps.
Although six of the studies reported in Hischier and Walser (2012) considered the end-of-life
phase, the treatment of the ENM was omitted. Municipal solid waste incineration models
used did not consider the amount or fate of ENMs as a separate flow (Hischier and Walser
2012).
33
Strategies
Klöpffer et al. (2007) note that the goal and scope definition should reflect issues such as: the
use of nanoproducts being in line with the product recommendation or predictions, and
potential rebound effects resulting from the use of nanoproducts. To address these issues the
use of sensitivity analysis is recommended in the interpretation phase.
4.2.2 Life cycle inventory analysis (LCI)
Obstacles
Ensuring the collection and use of complete, reliable, transparent and acceptable data,
including the explanation of assumptions, are problems faced during the LCI phase of LCAs
of ‘conventional’ product systems (Klöpffer et al. 2007). However, when LCA is applied to
nanotechnologies and ENMs these problems are amplified (Klöpffer et al. 2007). As such,
Hischier and Walser (2012) note the core issues of the LCI phase is the availability or
adequate and comprehensive LCI data from ENMs.
LCA of an emerging technology
Klöpffer et al. (2007) suggest that it is difficult to apply a “full-spectrum” LCA to emerging
technologies due to the lack of detailed knowledge regarding the inputs and output of the
system. Nevertheless, there is a general trend to apply LCA to emerging technologies (e.g.,
solar, wind, bio-fuels) (Klöpffer et al. 2007).
In the case of CNTs, Upadhyayula et al. (2012) note that the application of LCA is a
challenging task because many of the technologies studied are still emerging; introducing a
great degree of uncertainty and complexity into LCA. Obtaining accurate data for emerging
technologies can be a challenge because data based on conceptual designs, and assumption
about the scaling up of laboratory or pilot scale process may not accurately reflect industrial
scale operations. Additionally, early prototypes may undergo several changes during product
development and testing that can alter how a product is manufactured and used
(Upadhyayula et al. 2012). Furthermore, Upadhyayula et al. (2012, 43) note that one of the
greatest challenges when assessing nanoproducts is the “variable nature of manufacturing
processes and how subtle differences in the resulting nanocomponents can affect the
associated nanoproduct”.
Data availability
Klöpffer et al. (2007, 6) state that “The main problem with LCA of nanomaterials and
nanoproducts is the lack of data and understanding in certain areas.” Studies analysed in
Gavankar (2012) and Hischier and Walser (2012) show data on the input side covers energy
inputs and in most cases material inputs, yet in the great majority of studies the output side
is empty.
Gavankar et al. (2012) note that presently available LCI databases, populated with material
and product flows, do not distinguish between bulk materials and ENMs. Standard LCIs only
require the quantity and chemical composition of material inputs. In some cases, additional
characteristics are required for materials such as its isotope, stereo-isomer or valence
(Klöpffer et al., 2007). Parameters likely to influence the toxicity of ENMs include the chemical
composition, particle size, shape, aspect ratio, crystal structure, surface area, surface
chemistry and charge, solubility, as well as adhesive properties and whether the ENM is in a
pure form or in a composite (Klöpffer et al. 2007). Furthermore, it is important to know if
34
ENMs change their form during their life cycle, due to aging and other influences such as
weather, mechanical stress/pressure, electromechanical fields or catalysis (Klöpffer et al.
2007).
Indeed, Gavankar et al. (2012) highlight the lack of information on the production processes,
suggesting that it will take substantial effort and time to build an understanding on the
behaviour and impact of ENMs in order for the LCI and LCIA to be able to fully address their
potential environmental impacts.
Data confidentiality
Klöpffer et al. (2007) highlight the difficulty in acquiring proprietary information from
companies, especially from the producers of materials. In some cases, the exact composition
of the ENM is confidential. Hence, the challenge lies in the coordination of a compromise
between the interests of industry (confidentiality) and the interests of the LCA community
(acquiring data at an appropriately aggregated level).
Data quality
Hischier and Walser (2012) note that for LCA studies of CNTs, data for some processes in
some production technologies varied significantly. For instance, the CED for the production
of high-pressure carbon monoxide differed by a factor of approximately 10,000, and up to
almost 100,000 for the chemical vapour decomposition process. Additionally, Khanna et al.
(2008) suggest that the industrial scale nano-LCA results may be gross overestimates due to
expected increases in efficiency over time.
Capital goods
Klöpffer et al. (2007) highlight the large and energy-consuming capital equipment required
to manufacture ENMs (such as lithography and ultra-clean rooms) which can rapidly become
out-dated due to the fast pace of progress in the field. Hence, nanotechnology may be a case
where the capital goods are required to be included in the system boundaries (Klöpffer et al.
2007). This leads to two issues, the collection of data required to model the impact of capital
goods and the problem of allocation due to the multiple products/services than capital
goods may provide (Klöpffer et al. 2007).
Strategies
A case study approach
Emerging technologies do not lend themselves to analysis by a complete thorough LCA due
to insufficient knowledge regarding the inputs and outputs of the system (Klöpffer et al.
2007). Joshi (2008, 487) highlights the need to “generate comprehensive, transparent,
representative, and publicly available data for various process and material developments in
nanotechnology that satisfy the data quality requirements outlined under ISO standards for
LCA”.
Concerning strategies to address the lack of information regarding LCI and LCIA data,
Hischier and Walser (2012) identify two opposing strategies: ‘from back to front’, and ‘from
font to back’.
From back to front: addressing data gaps in the LCIA before “representative and
comprehensive” LCIs are established. This strategy is not recommended as following such a
35
trajectory has been evaluated as ineffective (Hischier and Walser 2012). Gavankar et al. (2012)
also highlight the critical importance of populating LCI databases with nano-specific
information.
Furthermore, Kuiken (2009) highlighted that the main obstacle for defining the environmental
effects of specific ENMs is the slow advancement of metrology10. Without the ability to
monitor emissions and conduct full scale ecosystem and human health effect studies on
ENMs, full-scale LCAs cannot be properly performed.
From front to back: Hischier and Walser (2012) recommend, as a first step, the collection of
inventory data. The authors highlight the need for inventory datasets with a high level of
representativeness of certain ENMs. Klöpffer et al. (2007) also suggest that a case-study
based approach should be adopted.
In following such an approach, LCI databases for specific ENMs and products can be
populated with nanomaterial-related input and output flows of emissions and resources,
supplementing them with information likely to influence the toxicity of ENMs (detailed
above) which are necessary for the characterization step of the LICA (Gavankar et al. 2012).
The Swiss Centre for Life Cycle Inventories, Ecoinvent, currently differentiates particulate
matter (PM) in the following categories: PM greater than 10 µm (PM>10), PM from 10 to 2.5
µm (PM10) and PM smaller than 2.5 µm (PM2.5) (Frischknecht et al. 2004). Bauer et al. (2008)
note that one option would be to differentiate UFPs, i.e. a category for PM 0.1.
Two approaches to the selection of appropriate case studies can be identified. Klöpffer et al.
(2007) recommend that the selection of case studies should prioritise criteria including the
most toxic products, nature of dispersion, high volume production and fate and transport
issues. Bauer et al. (2008) suggest the targeting ENMs with a high potential for future
industrial application. The authors suggest that for the materials listed in Table 8, the most
common production method should be identified and the LCI of these materials should be
populated with ENM specific information.
10
The science of measurement; this underpins nanoscience and nanotechnologies as it allows the
characterisation of materials not only in terms of dimensions but also in terms of attributes such as
electrical properties and mass. (Royal Society 2004)
36
Table 8: Nanomaterials with a high potential for future industrial applications (Reproduced from Bauer et
al. (2008, p.915)
Material Category
Carbon
nanomaterials
Nanocomposites
based
Metals and alloys
Biological nanomaterials
Nano polymers
Nano glasses
Nanoceramics
Application
Carbon black, carbon nanotubes, fullerenes, carbon nanofilms, etc.
Polymer matrix nanocomposites, ceramic matrix nanocomposites,
metal matrix filled with nanopolymer composites
Ti, Ti-Al, Ti-transition metal alloy, Mg-Ni, Fe-Cu-Nb-Si-B alloy, Fetransition metal alloy, Al-transition metal alloy, Al, Mg, Al-Mg alloy,
nanopowders of noble metals (Ag, Au, Pt, Pb)
Protein-based materials, peptides, carbohydrates, virus particles,
lipids, DNA, composites
Metallic glasses, electrochromics, nanoporous glasses, nanochannel
glass materials, photonic glasses, etc.
Tungsten carbide, alumina, zirconia, titania, silica, zinc oxide, silicon
nitride, magnesia, ferric oxide, ceria, hydroxyapatite (HAP), yttria,
silicon carbide, boron nitride, TiC, amorphous silicon nitride, etc.
An Input-output approach
In order to take account of the issues such as capital goods, Klöpffer et al. (2007) suggest that
input-output based LCA (IO-LCA) approaches, as input-output based models consider all
elements in a product’s supply chain. This includes direct and indirect purchases required to
produce a final product, including capital goods required to produce ENMs themselves and
the capital goods required to produce chemical feedstock for ENMs.
4.2.3 Life cycle impact assessment (LCIA)
Obstacles
The meta-studies conducted by Hischier and Walser (2012) and Gavankar et al. (2012),
indicate that the most common impact categories selected in LCA studies of ENMs related to
energy consumption (CED and GWP).
Due to their size and unique functionality, the properties of ENMs are different from their
conventional counterparts (Oberdörster et al. 2005). This may lead to them exhibiting
unconventional behaviour, leading to unexpected fate, transport, and toxicity mechanisms in
human and ecological systems (Gavankar et al. 2012). Hence, it is difficult to address potential
toxic impacts of ENMs on humans and the environment (Klöpffer et al. 2007).
Klöpffer et al. (2007, 20) conclude that the UNEP/SETAC framework for toxic impacts “can, in
principle, be used for specific impacts caused by nanoparticles and nanoproducts given that
(nanomaterial-specific) fate, exposure and effects have been adequately identified” (emphasis
added). However at this current point in time, Klöpffer et al. (2007) note that there are limits
regarding its application, especially relating to the assessment of toxicity impacts (Klöpffer et
al. 2007, 6).
At the centre of the ENM discussion is risk associated with the possible release of ultra-fine
particles (UFPs) and their potential impact on human health and the environment (Bauer et al.
37
2008). Characterisation of particle emissions is conventionally made according to their
particle size (aerodynamic diameter): coarse particles (between 10 and 2.5 µm), fine particles
(<2.5 µm) and UFP (<0.1 µm) (Englert 2004). In current impact assessment methods, outdoor
emissions of particulate matter (PM) of size <10 and <2.5 μm are assessed, and their
contribution to various impacts on the natural environment and human health (e.g., climate
change, ozone depletion, acidification, eco-toxicity and human toxicity) is quantified (Hischier
and Walser 2012).
However, basic research concerning the toxicological effects of UFP and their risks for human
health and the environment is still in its infancy and only few data on the safety of ENMs is
available (Bauer et al. 2008). Since contribution of UFPs to the various impacts on human
health and the environment is not known (Hischier and Walser 2012), LCIA methods such as
CML 2001, Eco-Indicator 1999 or Impact 2002 do not cover toxicological effects of UFPs
(Bauer et al. 2008). The current understanding of effect mechanisms, dose-response
relationships, as well as transport and transformations in the environment may not be
sufficient to ascertain a representative characterization of ENMs. (Klöpffer et al. 2007, 19).
A significant “retooling” of existing tools, such as USEtox (Rosenbaum et al. 2008), CALtox
(McKone and Enoch 2002) and QSAR (Dudek et al. 2006; Puzyn et al. 2009, 2010), would be
required for them to account for the intrinsic and extrinsic factors that control the behaviour
of ENMs (Gavankar et al. 2012).
However, such work is underway. The modification of QSAR (Quantitative structure-activity
relationship) to QNAR (quantitative nanostructure–activity relationship) (Fourches et al. 2010),
to assess the biological effects of engineered nanoparticles based on their physical, chemical,
and geometrical properties has recently been proposed (Gavankar et al. 2012).
Additionally, Klöpffer et al. (2007) highlight increased dissipative use of scarce resources
(such as indium, used in semiconductors) in nanotechnologies may lead to the need for
reaching consensus on a framework for the characterization of abiotic resource depletion.
Strategies
Klöpffer et al. (2007) note that major efforts are needed (in terms of protocols and practical
methodologies for toxicology studies, fate and transport studies and scaling approaches) in
order to fully assess the potential risks and environmental impacts of nanoproducts and
materials. The authors suggest that in order to assess the impacts from ENMs and
nanoproducts, one should wait for the development of approaches used for the regulative
RA of which can then be adapted for the comparative assessment of potential impacts in
LCA. Klöpffer et al. (2007, p.19) note that the following types of studies still need to be
undertaken for ENMs:
- “Protocols and practical methodologies for toxicological studies;
- Fate and transport studies; and
- Scaling studies (i.e., how properties such as surface area, conductivity and magnetism
change with the size of the nanomaterial).”
Alternatively, Klöpffer et al., (2007) suggst one immediate action could be attempts to define
categories of ENMs, based on currently available information, for the specific purpose of
38
LCIA, including categories, such as reactivity, degradability/fate and transport, and ecotoxicity vs. human toxicity. In this case, categorization should address:
- Dispersive vs. non-dispersive uses
- Chemical composition
- Form and structure
- Mobility of releases in the environment (air emissions, water release, waste, etc.) at
each life cycle stage. Reactivity, fate and transport, and interactions with other sources
of environmental impacts should also be addressed. (Klöpffer et al. 2007, 21)
Qualitative Screening Approach
The fact that there are significant data and methodology gaps does not mean that the impact
of ENMs on human health and the environment should be ignored or omitted. Screening
approachs have been suggested as an interim device to identify potentially significant issues
and explore worst-case scenarios (where ENMs have an impact potential as high as that of
the most toxic chemicals (Klöpffer et al. 2007; Gavankar et al. 2012).
Scalability
Gavankar et al. (2012) propose approach outlined in Figure 12 when faced with the limited
data concerning ENMs.
Figure 12: Flow chart recommending the nanomaterial assessment path depending on the availability of
data (reproduced from Gavankar et al. (2012))
39
In some cases, for instance some metal and metal oxide ENMs (see Auffan et al (2009))
scalability is known to exist. In these cases, the assessment of ENMs can be based on
traditional characterization approaches for bulk materials. The LCI data for the conventional
materials can be used in the place of the lacking ENM specific data, and the fate–transport
and toxicity assessment approaches can be used in the LCIA (Gavankar et al. 2012).
In cases where scalability cannot be established, (when particle size is below the threshold for
conventional material properties to be applied), Gavankar et al. (2012, 300) suggest exploring
any “empirical relationships, even if simplified, between ENM properties and their impact on
human health and environment based on the existing literature, engineering, industrial, and
other publicly available data”. Hence, empirical relationships may provide an early input for
nano-specific assessments until specific data for ENM fate, transport, and toxicity become
available (Gavankar et al. 2012).
When no quantitative data exists, qualitative assessment can be performed based on the
available information on the ENM and its release pathways. Bauer et al. (2008) and Gavankar
et al. (2012) discuss the qualitative approach proposed by Reijnders (2006) which
distinguishes between inherently non-dispersive11 and inherently dispersive nanoparticles12.
Inherently dispersive nanoparticles may be further classified according to the likelihood of
their dispersion in conjunction with their size range (Gavankar et al. 2012). Bauer et al. (2008,
p. 916) suggest that “more in-depth toxicological studies about these materials are of crucial
interest hence, as long as no such study results are known, these materials have to be
avoided as far as possible”.
11
Such as coatings, textiles, ceramics, membranes, composite materials, glass products, prosthetic implants, antistatic packaging, cutting tools, industrial catalysts, a variety of electric and electronic devices including displays,
batteries and fuel cells (Royal Society 2004)
12
Such as drugs, personal care products such as cosmetics, quantum dots and some pilot applications in
environmental remediation (Royal Society 2004).
40
5 RISK ASSESSMENT OF NANOMATERIALS
5.1 Risk assessment
Although some RAs have been conducted for ENMs according to standard RA protocols,
Grieger et al. (2012) suggest that all have concluded, due to limited data and the presence of
large uncertaitintites, it has not be possoible (based on the currently available information) to
complete full RAs for regulatory decicion making. Hence, any results to date should be
considered as pleminary results. The authors note that there is a lack of measured exposure
data for ENMs, lack of validated exposure estimation models, extensive uncertainties within
characterizing ENMs and a lack of (eco)toxicological studies in a variety of species. Hence, it
is difficult to complete hazard identification, dose–response and exposure assessments for
most ENMs (Grieger et al. 2012).
5.2 The complementarity of RA and LCA
The European Commission’s Nanoscience and Nanotechnologies An action plan for 2005-2009
(European Commission 2005) suggests that “Risk assessment related to human health, the
environment, consumer and workers should be responsibly integrated at all stages of the life
cycle of the technology, starting at the point of conception and including R&D,
manufacturing, distribution, use and disposal or recycling “(European Commission 2005, 10).
Several authors have recommended the application of both LCA and RA to ENMs. On the one
hand, it has been suggested that further efforts should be made for RA to consider life cycle
concepts, and on the other hand, LCA should be more risk based when applied to ENMs
(Sweet and Strohm 2006; Som et al. 2010). It has also be suggested that the risk of ENMs be
analysed at each life cycle stage (Shatkin 2008).
RA and LCA are tools that estimate the potential impact of a given substance or product,
notwithstanding the fact that they vary in aim, scope, outcomes, strengths and weaknesses
(Grieger et al. 2012). The difference in outcomes, strengths and weaknesses of these tools are
shown in Table 9.
Table 9: Outcomes, strengths and weaknesses of LCA and RA
Outcomes
Strengths
weaknesses
LCA
Comparative basis
Includes impacts from all life cycle
stages
- Includes a range of impact
categories
- Avoids in ‘burden shifting’, from one
impact category to another and from
one life cycle stage to another
- requires substantial amounts of data
- ineffective in handling uncertainties
and lack of data
- strong expert knowledge required
-
41
RA
- Absolute basis
- the provision of an absolute assessment
of the potential risk for specific settings
- the use of worst-case evaluations to
help ensure safety to a potential
adverse effect
-
requires substantial amounts of data
ineffective in handling uncertainties and
lack of data
strong expert knowledge required
Similarities and differenced between LCA and RA have been identified by Grieger et al.
(2012). Similarities include: providing a way of structuring, presenting and evaluating
information for environmental decision-making in a life cycle perspective (although
possessing different conceptions of life cycle) (Flemström et al. 2004), estimation of
exposures and effects from emissions (Olsen and Christensen 2001), both contain methods to
characterise uncertainty within the assessments (Evans et al. 2002), and both help in
providing information to support decisions in situations of uncertainty (Evans et al. 2002).
Differences include: LCA’s focus on the product/service system and RA’s focus on the
emissions of a single substance (Christensen and Olsen 2004), different system boundaries
and ‘life cycles’ are used (Christensen and Olsen 2004), the results of LCA are comparative
whereas the results of RA are absolute (Grieger et al. 2012), and LCA covers a range of
environmental impacts whereas RA primarily cover toxicological and (eco)toxicological
impacts.
Grieger et al. (2012) have identified two main approaches that have been proposed for
combining LCA and RA for ENMs: life cycle-based risk assessment (LC-based RA) and risk
assessment-complemented life cycle assessment (RA-complemented LCA). The authors note
several research articles, frameworks and recommendations that apply these two approaches,
most of them describing the use of the RA-complemented LCA. In addition, there are very
few concrete case studies in the peer-reviewed literature that have tested and validated these
approaches.
5.2.1 Life cycle based risk assessment
LC-based RA is an approach that applies traditional RA in a life cycle perspective (Grieger et
al. 2012). This is done to help “concentrate efforts where it is the most needed, i.e., at each
life-cycle stage” (Grieger et al. 2012, 9), and is considered an extension of standard RA in a
life cycle perceptive (as required by REACH).
Wardak et al. (2008) recommends using LCA and RA methods based on scenario analyses
with expert elicitation, specifically focusing on ENMs or nanoproducts during the use and
disposal stages (Grieger et al. 2012).
5.2.2 Risk assessment complemented by life cycle assessment
RA-complemented LCA consists of a conventional LCA (assessing the environment impact of
a product) complemented with either a quantitative, semi-quantitative or qualitative RA
which assesses the risks related to specific life cycle stages (Grieger et al. 2012). The authors
note that this approach is the only approach that really combines life cycle and RA based
methods for ENM risk. Grieger et al. (2012) note that most publications and risk analysis
frameworks utilise this method.
5.2.3 A Stream lined approach
Klöpffer et al. (2007) outline a screening approach, combining the use of LCA, RA and
scenario analysis, to be used by industries (including SMEs) and stakeholders involved in the
development of ENMs and nanoproducts in order to identify the main areas of concern in
relation to the potential environmental impacts and to support go/no go decisions. Five steps
where highlighted in this screening approach are illustrated in Table 10.
42
Table 10: Proposed Stepwise approach to LCT combined with RA
Steps
Purpose
1. Check for obvious - Compliance with
harm
health, safety and
environmental
regulation
2. Traditional LCA
- Understanding
without toxicity study
burdens versus
(focus on environmental
benefits
impacts)
- If substantial benefits,
then go forward
3. Toxicity and RA (or
qualitative analysis)
could include toxicity
and risk questions
4. Combine LCA and RA
5. Scenario Analysis
What Is Available
- Usual assessment
methods in industry
What Is Missing
- Analogies with
- Some LCI data on
existing materials
nanomaterial
- Confidential info
production
available to the “right” - Interface – to be
people
developed to deal
- Software with easy towith fuzzy inputs use interface
should this be sector
- If material is not listed,
or region- specific?
use what’s similar
- Find ways to make
confidential
information available
within industry
- What are the likely
- Confidential
- Hazard and exposure
adverse risks that
information available
data (potential
humans and other
to the “right” people
primary and
organisms will be
- Quantitative or fuzzy
secondary
exposed to at each life - Published information
transformation into
cycle stage
is available
unknown toxic
- How structure of
substances across life
material influences
cycle stages)
behavior (surface,
- Find ways to make
area, shape, etc.)
confidential
information available
within industry
- To assess overall
- No standard
impacts over whole
quantitative tool
life cycle
available to merge
- Can evaluate impacts
the data
from the interaction of
materials
- To scale- up to
- Lack of reasonable
society-wide use
upper and lower
(consider issues such
bounds for scaling
as resource depletion)
and impact
estimations
43
6 SUBSTANCE FLOW ANALYSIS OF NANOMATERIALS
6.1 Research applying SFA and PFA to nanomaterials
6.1.1 Literature review
Conducting a comprehensive meta-analysis of the state-of-the-art of SFA research on
nanomaterials is beyond the scope of this report. Whilst highlighting some of the current
research results, our primary objective is to focus on the potentials and limitations of current
research efforts in order to propose research priorities.
A search of academic literature databases (Scopus, ScienceDirect) and an internet search for
publications (such as those in scientific journals, conference proceedings, conference
presentations, research reports and theses) was conducted using the following combination
of keywords
- nano + substance flow analysis
- nano + “substance flow analysis”
- nano + SFA
- nano + material flow analysis
- nano + “material flow analysis”
- nano + MFA
- nano + particle flow analysis
- nano + “particle flow analysis”
- nano + PFA
Table 11 highlights the peer reviewed scientific literature on nanotechnology and ENMs
conducted from a SFA perspective.
44
Table 11: Case studies applying substance flow analysis to nanomateirals
Author
ENM
Arvidsson et
al. (2011)
System
Case Study
Ag
Generic
Arvidsson et
al. (2012a)
Blaser et al.
(2008)
TiO2
Generic
Ag
Water
EU
Boxall et al.
(2007)
TiO2,
ZnO,
CeO2,
Al2O3,
SiO2,
Au,
Ag,
C60
TiO2,
ZnO,
Ag,
CNT,
C60
TiO2,
Ag,
CNT
TiO2,
ZnO,
Ag,
CNT
TiO2,
Ag,
CeO2
CeO2
Water, sludge,
soil, air
UK
PFA of nanosilver emissions from dissipative and
non-recyclable products (wound dressings and
textiles).
PFA of titanium dioxide nanoparticles from
sunscreen, paint and cement.
Dissolved silver (Ag) emissions from nano-silver
containing biocidal products (textiles and plastics)
were compared to the expected concentrations in
the environment. Nanosilver is only responsible for
a small share of the total dissolved silver flow in
the environment, but did not consider any
particulate emissions.
Based on an assumption of 10% market
penetrations of nanoproducts and the known
usage of these products, concentrations of silver,
aluminum oxide and fullerene were predicted to be
in the ng/l in wastewaters, whereas nano-TiO2,
silica, ZnO and hydroxyapatite were predicted to
be in the µg/l range.
Water, sludge,
air, sediments,
soils,
groundwater
CH, EU,
USA
Stochastic simulations of the release of all
considered ENM to environmental and technical
compartments during all life-cycle stages
Water, air, soil
CH
Release of TiO2, Ag, CNT to environmental and
technical compartments.
Water, air, soil
CH
The flow of TiO2, ZnO, Ag, CNT during waste
incineration and landfilling.
Air, surface
water
Ireland
The release of TiO2 from exterior paints, Ag from
food packaging and CeO2 from fuel additives
Air, Soil
Generic
The release of CeO2 from fuel additives
Gottschalk
et al. (2009)
Mueller and
Nowack
(2008)
Mueller et
al. (2013)
O’Brien and
Cummins
(2010)
Park et al.
(2008)
Compartments
45
6.1.2 Results from selected case studies
Release of nanosilver and nano titanium dioxide during the use phase
Arvidsson et al. (2011) and Arvidsson et al. (2012a) are outcomes from the Swedish research
programme NanoSphere: Centre for interaction and risk studies in Nano-Bio-Geo-Sociotechnosphere interfaces13. This research programme is a cooperation between twelve research
groups from three faculties at University of Gothenburg and from Chalmers and funded by
FORMAS (25 million SEK from 2010-2014).
Arvidsson et al. (2011) and Arvidsson et al. (2012) applied PFA to estimate the global current
emissions, and future emissions, of nanosilver (in wound dressings, textiles and nanosilver ink
in electronic circuitry) and nano titanium dioxide (in sunscreen, paint and cement) to the
environment. Both of these studies focused on the use phase, as the production phase
emissions are highly dependent upon individual company’s management practice and there
is poor knowledge on the fate of nanosilver during the waste-handling phase.
Current and future production of nanosilver and nano titanium dioxide were analysed. The
authors developed an exploratory scenario to assess the potential future development of
nanosilver and nano titanium dioxide applications. The assumptions behind the nanosilver
case were that application will reach 100% market share within the product group in
question, the per capita in-flow to the use phase and stock of the product group will be
equal to those found in today’s high-income regions, and the world population will increase
to 10 billion people by 2050. The assumptions behind the nano titanium dioxide case were
that the world average demand per capita for nano titanium dioxide applications are equal to
the current demand in developed countries and that the world population will increase to 10
billion people by 2050.
Nanosilver
The current production of the nanosilver for wound dressings, textiles and electronic circuitry,
was suggested to be 254 kg/year, < 4,700 kg/year, and < 4,700 kg/year, respectively. The
current and future in-flow, stock and emissions of nanosilver particles are summarised in
Table 12.
Table 12: Current in-flow, stocks and emissions during the use phase for nanosilver applications in
wound dressings, textiles, and electronic circuitry (adapted from Arvidsson et al. (2011))
Output parameter
Current
production
Current stock
Current emissions
Explorative
scenario
production
Explorative
scenario stock
Explorative
scenario emissions
13
Symbol and unit
particles/year
Wound dressings
22
4.6 x 10
Textiles
23
< 8.5 x 10
Electronic circuitry
24
< 6.8 x 10
particles
particles/year
particles/year
Insignificant
21
4.6 x 10
22
25
(1 x 10 , 1 x 10 )
Insignificant
23
< 8.5 x 10
28
32
(6 x 10 , 6 x 10 )
< 6.8 x 10
24
< 6.8 x 10
27
9 x 10
particles
Insignificant
Insignificant
9 x 10
particles/year
(1 x 10 , 1 x 10 )
21
24
http://www.nanosphere.gu.se/
46
28
25
28
32
(6 x 10 , 6 x 10 )
27
< 9 x 10
The highest inflow of nanosilver particles to the use phase occurs from their use in electronic
circuitry followed by textiles and wound dressings. Due to the short product life of wound
dressings, no stock of nanosilver is formed during the use phase. Likewise, there is no stock
of nanosilver from its use in textiles, as it is assumed to be emitted during the first few
washes. The life span of electronic circuitry was assumed to be 10 years, resulting in a stock
of < 6.8 x 1025 nanosilver particles.
Whilst the emissions for nanosilver from textiles reported in this study are very uncertain, the
authors highlight the importance these emissions during both the current use phase and
their potential future emissions.
Nano titanium dioxide
This study analysed the current and future emissions of titanium dioxide nanoparticles from
the use phase of their applications in sunscreens, paints and self-cleaning cement. The
current production of nano titanium dioxide used for paint and sunscreen was suggested to
be, 29,000 kilotonnes/year and 72 kilotonnes/year, respectively. The production of nano
titanium dioxide for self-cleaning cement was reported as being negligible. The current and
future in-flow, stock and emissions of titanium dioxide nanoparticles are summarised in Table
13.
Table 13: Current in-flow, stocks and emissions during the use phase for titanium dioxide nanoparticle
applications in paint, sunscreen, and self-cleaning cement (adapted from Arvidsson et al. (2012))
Scenario
Output parameter
Symbol and unit
Paint
Current
Inflow to use phase
Stock in use
Use phase emissions
Inflow to use phase
Stock in use
Use phase emissions
particles/year
particles
particles/year
particles/year
particles
particles/year
1 x 10
26
1 x 10
19
1 x 10
25
7 x 10
26
7 x 10
19
8 x 10
Explorative scenario
Sunscreen
25
25
2.6 x 10
Negligible
25
2.6 x 10
26
2 x 10
Negligible
26
2 x 10
Self-cleaning
cement
Negligible
Negligible
Negligible
27
9 x 10
28
9 x 10
27
< 9 x 10
The highest inflow of nano titanium dioxide particles to the use phase occurs from their use
in sunscreen, even though the mass of nano titanium dioxide in paint applications is more
than 400% greater than in sunscreen applications. This is a result of the much smaller nano
titanium dioxide particles used in sunscreen applications compared to paint.
Regarding the future inflows and stocks of nano titanium dioxide, the most important
application is self-cleaning cement, due to the small particle size (almost equal to the size
used in sunscreen) and the significant growth potential for this application.
The authors note that majority of nano particles in paint and self-cleaning cement are not
emitted during the use phase, but will be retaining in the materials when the pass through to
the end of life phase.
Due to the dissipative nature of sunscreen during the use phase, the authors note the
importance of the inflow of sunscreen from an emissions perspective, which is the case for
both the current and future scenario.
47
Flows of engineered nanomaterials during waste handling
Muller et al. (2013) have used SFA to predict the flows of nano titanium dioxide, nano zinc
oxide, nanosilver and carbon nanotubes during waste incineration and landfilling of
municipal solid waste and construction waste in Switzerland.
The inflows to the system consist of the direct deposit of construction waste to landfills for
inert wastes, and the incineration of municipal solid waste and sewage sludge. The
incineration process consists of a) burning under oxidisation conditions at around 1000°C, b)
flue gas filtration (electrostatic precipitator of bag house filter), c) flue gas scrubbing, and d)
waste water treatment for wastewaters from the cooling processes of the bottom ash, the
scrubber, and possibly from the acid washing of the fly ash.
Depending upon the physio-chemical properties of the ENMs, they may either be a)
destroyed by oxidation, melting or volatolisation in the furnace or by
dissolution/precipitation in the wastewater treatment plant or in the scrubber, or b) survive
incineration be found in either the bottom ash or fly ash, be released into the air or the
quench water.
Figure 13 shows that the major flows for nano titanium oxide, nano zinc oxide and nanosilver
from the incineration process go to landfill as bottom ash. The second most significant flow
of ENMs to landfill was via the direct deposition of construction waste. For CNTs, 94% were
combusted with insignificant amounts remaining in the system. Very small amounts of nano
zinc oxide (< 5 t/year), nanosilver (< 5 t/year), and CNTs(< 100kg /year), were predicted to
enter landfills. However, up to 150 t/year of for nano titanium dioxide was predicted to enter
landfills.
Figure 13: Flows of ENMs during waste disposal shown as a % of the total flow that enters the
incineration/landfill system (Reproduced from Muller et al. (2013))
48
6.2 Potential life cycle release and exposure of nanomaterials
Som et al. (2010) note that the assessment of human and environmental exposure is closely
linked to the release potential of ENMs during the different life cycle stages. To this end, it is
important to know in what form (as ‘free’ ENMs, in an aggregated or agglomerated form, or
integrated into a nanometre or micrometre sized material) and in what life cycle stage ENMs
can be released.
6.2.1 Production of nanomaterials and manufacture of nanoproducts
Som et al. (2010) and Gottschalk and Nowack (2011) note that the greatest likelihood of
direct release and exposure to ENMs is during their manufacture. Direct release and exposure
to ENMs already occurs and is mainly due to the production and handling of dry powders
(see Bello et al. (2008), Han et al. (2008) and Fujitani et al. (2008)). Gottschalk and Nowack
(2011) suggest that once the ENMs are released to indoor air it is likely that they will sooner
or later enter into the environment. The authors also suggest ENMs may be directly released
to the environment through open windows during the improper handling ENMs, from
transport accidents and other types of spills.
Concerning the production of ENMs, Gottschalk and Nowack (2011) note that recent studies
on the direct release to the environment show uniform probability distributions ranging from
0 to 2% of the ENM produced. The authors note that generic worst-case scenario release
coefficients for chemicals and the manufacturing process of such chemicals consider that 5%
are released to the air, 6% to surface waters before reaching a sewage treatment plant and
0.01% to soils. However, depending on the production and maintenance procedures used, it
may be possible that only a negligible release to the environment occurs when closed
systems and solvent-free procedures are implemented and all waste from cleaning and
maintenance is disposed of as special waste (Gottschalk and Nowack 2011).
For the manufacture of nanoproducts, Gottschalk and Nowack (2011) note that recent studies
on the direct release to the environment show uniform probability distributions ranging from
0 to 2% of the ENM produced. Generic worst-case scenario release coefficients for
formulation of mixtures (not embedded into a matrix) considers that 2.5% are released to the
air, 2% to surface waters before reaching a sewage treatment plant and 0.01% to soils
(Gottschalk and Nowack 2011).
The indirect release of ENMs during the production phase may be via untreated or treated
water to rivers (Gottschalk and Nowack 2011). For instance, the production of fullerenes or
carbon nanotubes results in the production of a greater proportion of waste that contains a
variety of carbon-based structures whose characterisation is not yet available (Gottschalk and
Nowack 2011).
49
6.2.2 Use phase
The exposure of ENMs during the use phase can result from the intended or unintended
release of nanoparticles (Som et al. 2009). The intended release of nanoparticles results from
either point sources, such as the use of ENMs in groundwater remediation, or non-point
sources, such as the use of ENMs in products such as sunscreens (Som et al. 2009; Gottschalk
and Nowack 2011). Som et al. (2009, p, 166) suggest that the exposure of consumers to nonpoint sources could be estimated using “behavioural and anthropometric data, usage
statistics, and from the prevalence and manner of integration of ENMs in different product
categories”. Furthermore, the magnitude of ENM released via point sources is generally
known.
The unintended release of nanoparticles results from the use of ENM in products such as
nanosilver in textiles (Som et al. 2009; Gottschalk and Nowack 2011). The release of ENMs
from products during their use depends on several factors, including the amount of ENMs in
the product, how the ENM is embedded in the product, the products life time, and the actual
use of the product (Som et al. 2009; Gottschalk and Nowack 2011). Som et al. (2009) suggest
that products that have a loose incorporation of ENMs or an intense use will most likely not
contain any ENMs at the time of disposal. However, factors such as a low rate of use and
strong fixation would increase the likelihood of ENMs entering the disposal phase.
Hsu and Chein (2006) have shown the release of nano titanium dioxide from coatings on
wood, polymers and tiles, with UV light contributing to an increased release of ENMs. Vorbau
et al. (2009) have shown no significant release of nanoparticles from the abrasion of coatings
containing nano zinc oxide, and that after abrasion the ENMs were still embedded in larger
particles. Blaser et al. (2008) and Benn and Westerhoff (2008) have shown that nanosilver is
released in ionic form from plastics and textiles, and as nanoparticles released from washing
nanosilver containing textiles. Furthermore, the leaching of nano titanium dioxide to surface
water from facades treated with nano titanium dioxide containing paints has been
demonstrated (Kaegi et al. 2008).
50
6.2.3 End-of-life phase
Although there is little information about the behaviour of ENMs during the end-of-life
phase, it is assumed that there is a high risk that ENMs may be released to the environment
during recycling or disposal (Royal Society 2004). It is likely that there will be unintentional
releases of ENMs to the environment during either the recycling, incineration or landfill of
ENMs or via wastewater treatment plants. Hence, incineration plants, landfills and wastewater
treatment plants may be important sources for ENM releases to the air, water and soil.
Incineration
One pathway for ENMs to the environment is to the air via waste incineration plants
(Gottschalk et al. 2009). Although modern incineration plants are equipped with multi stage
flue gas cleaning systems (including electro filters, flue gas scrubbers,
catalytic/NOx/furane/dioxin removal and possibly fabric filters), low concentrations of ENMs
may be released to the air (Som et al. 2009). Burtscher et al. (2001) suggest that the
concentration of particles less than 100nm is reduced by filters by 99.9% and in subsequent
wet filtration by another 95%.
Roes et al (2012) calculate that by 2020 approximately 0.5 kg of ENM in plastics will
incinerated per ton of waste, equating to 1880 t/a of ENM entering Swiss waste incineration
plants as nano-composites. The authors suggest that the concentrations of nano-objects
found in the flue gas of waste containing nanocomposites would be 100-10 000 times higher
than conventional waste, assuming no EMNs are destroying and all ENMs end up in the flue
gas.
Landfill
Several authors (see Mueller and Nowack (2008) and Gottschalk et al (2010, 2009)) have
shown a significant flow of ENMs to landfill, either via deposition of bottom or fly ash, from
the incineration of wastewater sludge, or via the direct dumping of construction waste. Som
et al. (2009) note that the degradation of nanoproducts containing ENMs in landfills is yet to
be studied.
Recycling
The ability to recycle ENMs or nanostructured materials containing ENMs is uncertain. For
some nanoproducts such as lithium batteries with a complete recycling system, no release of
ENMs to the environment is expected (Som et al. 2009). A recent experimental study by
Busquets-Fité et al. (2013) on the recovery of silicon dioxide, titanium dioxide, zinc oxide and
WMCNTs from polyamide-6 (PA) and polypropylene (PP) composites has shown recovery
rates of between 0 and 99%, as detailed in Table 14.
Table 14: Recovery of ENMs from PA and PP composites
ENM
silicon dioxide (non-aged – aged)
titanium dioxide (non-aged – aged)
zinc oxide (non-aged – aged)
MWCNT (non-aged – aged)
PA
43-59%
60-59%
0-0%
50-45%
PP
98-95%
97-96%
99-99%
97-80%
However, currently ENMs are not recycled at significantly high rates and recycling process
such ‘shredding’ may lead to the release of ENMs.
51
Wastewater treatment
Gottschalk and Nowack (2011) suggest that one should expect at least some of the ENMs in
wastewater to end up in freshwater. Furthermore, it should also be considered that ENMs
may pass through several different technical compartments (the deposit of sludge from
waste incineration plants to landfill and/or the incineration of biosolids from wastewater
treatment plants) (Gottschalk and Nowack 2011).
Arvidsson et al. (2012b) have assessed the risk of silver exposure to earthworms from
applying sludge as fertilizer to agricultural land which contains nanosilver from clothing
applications. They have shown that low concentrations of silver found in clothes pose an
insignificant contribution to the total silver concentration in the waste water treatment plant
studied and that the concentration of silver in sludge was below the natural level found in the
earth’s upper crust. However, for high concentrations of silver in cloths it would be
impossible to reach the long-term goal of having the same concentration of silver in the
sludge as in Earth's upper crust. Furthermore, the authors suggest that for clothes with the
highest silver concentration, there is a substantial risk that the concentration of silver in the
soil would be toxic to earthworms, if the sludge were to be applied to agricultural land.
52
7 COMMUNICATION OF A LIFE CYCLE APPROACH TO
NANOMATERIALS
There exists a plethora of images used to represent the life cycle concept. They either are
generic representations of the life cycle concept, or represent specific information related to
the product/system service in question. These images generally belong to two categories,
linear representations and cyclical representations. Almost all graphical representations of
LCT have one aspect in common; they represent the connection between the life cycle phases
of a product (resource extraction, manufacturing/production, transport, use and end-of-life).
See Appendix B for generic, linear, general and specific life cycle images.
These images are useful to convey the life cycle perspective, however one important aspect
related to products containing ENMs that should be communicated is the release of ENMs to
the environment during different life cycle stages. Figure 14 highlights the flows and
potential releases of ENMs as a result of their incorporation into product life cycles. The blue
line represents ENMs in the product life cycle and also the potential emissions of ENMs
during a product life cycle.
Figure 14: Life cycle thinking and nanomaterials
53
8 RECOMENDATIONS
To ensure the safe handling of ENMs and to be able to identify opportunities in a life cycle
perspective requires better data and analysis, but also more effective decision-making and
policy instruments. The following suggestions identify some potential ways forward:











Improved information concerning the use of ENMs. In order to assess risk,
information is needed on the volumes society uses, in which applications, and in what
forms.
Improved information on emissions is required in order to assess the risks of
ENMs. As a first step, information is required on where emissions occur, which can be
achieved through undertaking simplified SFAs of ENMs. Methods for this need to be
developed where the reasonable worst-case assumptions can be made to assess
whether further detailed analysis is required. Those who place a material on the
market should be able to describe how the material will be disposed of or emitted to
the environment.
In depth SFA in specific cases. These cases can be selected for several reasons:
environmentally relevant ENMs, ENMs used in large quantities or ENMs that can be
considered representative of larger groups and thus can be used to develop and
verify the simplified models.
Measurements. SFA is based upon existing and available data which in turn need to
come from actual measurements or model calculations, which in turn needs to be
based on measurements. Examples of important situations where actual
measurements are required include exposure in the work environment, flows in waste
water treatment plants and flows associated with recovery processes and other waste
management activities.
Methods for the characterization of nanoparticles. The properties of nanoparticles
can change according to their shape and size. Nanoparticles need to be characterised
in ways that are relevant for emission measurements, exposure analysis and toxic
effects.
Toxicological and eco-toxicological dose-response data are needed.
Models for exposure analysis require further development and need to be
adapted for nanoparticles.
Environmental impact assessment methods in LCA require further development
and need to be adapted for nanoparticles. As the methods for risk assessment of
nanoparticles are developed, there is a need for LCA methodology to follow and
adapt.
LCI data for ENMs. LCA is heavily dependent on databases which have been
developed over the past decade. However, these databases are limited with regards
to ENM data. Life cycle inventory data is essential for the assessment of the potential
benefits and impacts of ENMs in a life cycle perspective.
Methods to develop life cycle data for emerging technologies. Nanotechnology is
a field experiencing rapid development; this also applies to manufacturing processes
and their environmental performance.
International cooperation with a Swedish perspective. Much of the data and
methods that are required for LCA should be developed in the context of
international cooperation. However, it may be important to develop life cycle data for
54





products manufactured in Sweden as some conditions may be country specific (for
example, raw materials and energy). Furthermore, other processes such as waste
management may have specific Swedish conditions.
The collaboration of industry, governmental agencies and research. Much of the
data which is required should be produced by industry. It is also important that
governmental agencies and researcher are involved in such work to ensure credibility
and transparency.
Credible information to users. The safe use of ENMs and nanoproducts requires
informed users. Labelling and other forms information is needed to be designed so
that users in businesses, organizations, government agencies and consumers can
make their own informed decisions.
Avoid locking in a risk paradigm. Full risk assessments require copious amounts of
data and take a significant amount of time to complete. It would be expensive and
inefficient to complete risk assessments on every ENM and its specific application that
is placed on the market. Hence, one must be able to make effective decisions about
the safe use of ENMs without full risk assessments.
Avoid a ‘material for material’ paradigm. The number of ENMs can be vast. In
order to have effective processes, decisions can be taken without the complete data
that is require for each individual material. Decisions can be made for groups of
materials, or based on more simple criteria.
Resources for research in several fields. There is need for research on data and
methods that can be used for SFA, RA and LCA. Research is also needed on the use of
ENMs, policy instruments and decision theory.
55
9 CONCLUSIONS
ENMs are used in a growing number of products. Their application in products can be either
inherently non-dispersive or inherently dispersive. Yet even ENMs in inherently nondispersive applications can be released to the environment during the life cycle of the
product.
The present assessment of the impacts, or benefits, of ENMs upon human health and the
environmental is currently inadequate. One of the most important contributing causes for
this inadequacy is the lack of data. Although there are a large variety of ENMs currently being
used, there are no official statistics available on the amounts of ENMs currently used and
products that contain ENMs.
Environmental and health risks are both related to the chemical composition of the ENMs,
but also the particles size, shape and properties. Hence, nanoparticles must be classified
according to more than their mere chemical composition.
There are major gaps in knowledge regarding the emission of ENMs and nanoparticles
during production, use and disposal. Models for dispersion and exposure analysis for ENMs
must be developed as well as dose-response data for toxic effects.
Full RAs of ENMs are difficult because of the lack of data and methods available. LCAs have
been completed for a number of products containing ENMs. ENMs are not considered in the
LCIA, hence there is no information presented concerning the environmental impact on
human health or the environment due to the release of ENMs.
Production of ENMs can often be energy intensive. However, in a life cycle perspective, the
use of ENMs may lead to reduced energy use that is greater than that caused by the
production.
To be able to both reach the safe use of ENMs and to exploit ENMs opportunities in a life
cycle perspective requires better data and analysis but also effective instruments and
decision-making.
56
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64
Appendix A
A.1
European Union FP7
Project
NANOSUSTAIN
Development of
sustainable
solutions for
nanotechnologybased products
based on hazard
characterisation
and LCA
Duration
2010-05-01 2013-04-30
Link
Description
Life Cycle Related Publications
http://www.nanosustain.eu
WP4 - life cycle assessment and prospective technological
assessment
developing methods for extrapolation and scaling-up
of processes of engineered nanoparticles;
developing specific exposure models for engineered
nanoparticles;
assessing positive and negative effects on the
environment during different life cycle stages of
selected nanoproducts;
developing criteria and guiding principles to foster the
precautionary design of ENMs and guidelines for
improved recyclability;
testing these guidelines to explore new solutions for
the sustainable use, recycling and final treatment of
selected ENMs.
PROSUITE
Development
and application
of standardized
methodology for
the PROspective
SUstaInability
assessment of
Technologies
2009-11-01
–
2013-10-31
http://prosuite.org
The project goal is “to develop a coherent, scientifically
sound, and broadly accepted methodology for the
sustainability assessment of current and future
technologies over their life cycle, applicable to different
stages of maturity”. It is noted that the PROSUITE
framework and software tools address the whole life cycle
(from a technology’s use of primary materials through to
the production and handling of wastes).
- Steinfeldt, M. 2012. LCA case studies
of nanotechnology based
applications in the project.
Conference on safe production and
use of nanomaterials: Nanosafe
2012. Grenoble, France. 13 ‐ 15
November 2012.
- Steinfeldt, M. 2013 Life Cycle
Assessment of nanotechnology
based applications. 2nd. QNano
International Conference. Prague,
Czech Republic. 27 February – 1
March 2013
- Steinfeldt, M. LCA case studies of
nanotechnology-based applications
in the project NanoSustain. Safety
Issues and Regulatory Challenges of
Nanomaterials. San Sebastian, Spain.
rd
th
3 - 4 May 2012.
- Walser, et al. 2011. Prospective
environmental life cycle assessment
of nanosilver T-shirts. Environmental
Science & Technology 45, 4570–
4578.
- Walser, T; et al., 2012. Persistence of
engineered nanoparticles in a
municipal solid waste incineration
plant. Nature Nanotechnology 2012,
7, 520–524
- Hischier, R &Walser, T, 2012. Life
cycle assessment of engineered
nanomaterials: State of the art and
strategies to overcome existing
Work packaging 6 contains four case studies. One focuses
on nanotechnology and covers specific application such as:
Antimicrobial nanoparticles and nanostructured
particles in textiles with particular focus on
occupational and consumer exposure.
65
Polymer nanocomposites as new engineering
materials
Electronic devices such as organic light emitting
diodes, field effect transistors and organic
photovoltaics.
The main objective is the monitoring of the life cycle of
three families of nanomaterials (carbon nanotubes,
nanoclays and metal oxide nanoparticles) when embedded
in selected polymeric hosts.
-
http://www.nanopolytox.eu
NANOPOLYTOX
Toxicological
impact of
nanomaterials
derived from
processing,
weathering and
recycling from
polymer
nanocomposites
used in various
industrial
applications
NANOHOUSE
Life Cycle of
Nanoparticlebased Products
used in House
Coating.
2010-05-012013-04-30
2010-01-012013-06-30
http://wwwnanohouse.cea.fr
NANEX
Development of
Exposure
Scenarios for
Manufactured
Nanomaterials
ENFIRO
Life Cycle
Assessment of
2009-12-012010-11-30
http://nanex-project.eu
2009-09-012012-11-30
http://www.enfiro.eu
Work Package 6 will study the influence of the processing
and recycling of nanomaterials and the weathering of
nanocomposites demonstrators, on the physical, chemical
and toxicological properties of the nanofillers. Predictive
models will be also developed that will be able to provide
the needed information about the evolution of
nanomaterials properties along their life cycle. Life Cycle
Impact Assessment (LCIA) will be performed based on
these predictive models.
NanoHouse project covers the whole risk assessment by
evaluating the exposure and the hazard. Through a
combination of knowledge from Life Cycle Thinking and
risk assessment, NanoHouse outlines a holistic and
prospective overview on the potential Environmental
Health and Safety (EHS) impacts of paints containing
Engineered NanoParticles (ENPs) throughout all life stages
of the paints.
Objective4 of NANEX is to collect and review data on
environmental release, risk management measures, and
existing models for estimating environmental release and
exposure during the various life cycle stages of MNMs for
HARNs, mass-produced MNMs and specialised MNMs
LCA case studies on the substitution options for specific
brominated flame retardants, which includes nanoclaybased flame retardants in printed circuit boards.
66
gaps. Science of the Total
Environment 2012, 425, 271-282
Martí Busquets-Fité et al. 2013.
Exploring release and recovery of
nanomaterials from commercial
polymeric nanocomposites . Journal
of Physics: Conference Series 429
012048
- Hischier, R &Walser, T, 2012. Life
cycle assessment of engineered
nanomaterials: State of the art and
strategies to overcome existing
gaps. Science of the Total
Environment 2012, 425, 271-282
- Gottschalk, F., Nowack, B., 2011. The
release of engineered nanomaterials to
the environment. Journal of
Environmental Monitoring 13, 1145–
1155.
EnvironmentCompatible
Flame
Retardants:
Prototypical Case
Study
Nano Impact Net
European
Network on the
Health and
Environmental
Impact of
Nanomaterials
NANOMICEX
Mitigation of risk
and control of
exposure in
nanotechnology
based inks and
pigments
NanoValid
Development of
reference
methods for
hazard
identification,
risk assessment
and LCA of
engineered
nanomaterials
LICARA
Life cycle
approach and
2008-04-012012-03-31
www.nanoimpactnet.eu
2012-04-012015-03-31
http://nanomicex.eu
2011-11-012015-10-31
http://www.nanovalid.eu
NanoImpactNet was a multidisciplinary European network
on the health and environmental impact of nanomaterials.
NanoImpactNet established to create a scientific basis to
ensure the safe and responsible development of
engineered nanoparticles and nanotechnology-based
materials and products, and to support the definition of
regulatory measures and implementation of legislation in
Europe
One objective of NANOMICEX is the development of novel
methods based on nanoparticle functionalization to reduce
hazards caused by potential nanoparticle emissions during
ink/pigment-based products life cycle. Work package 6
involves the Adaptive Streamlined Life Cycle/Risk
Assessment of nanoparticle-based inks and pigments.
The main objective of NanoValid is the development of
new reference methods and certified reference materials,
including methods for characterization,
detection/quantification, dispersion control and labelling,
as well as hazard identification, exposure and risk
assessment of engineered nanmoaterials.
Work package 4 will evaluate the potential of the methods
to perform hazard and risk assessment and life cycle
analyses of engineered nanmoaterials.
2012-10-012014-09-30
http://www.licara.eu
The specific objectives of LICARA include:
the development of a framework for LCA that properly
addresses risks in data scarce situations, and the
application of the life cycle approach in case studies.
67
- Som, C., Berges, M., Chaudhry, Q.,
Dusinska, M., Fernandes, T.F., Olsen,
S.I., Nowack, B., 2010. The
importance of life cycle concepts for
the development of safe
nanoproducts. Toxicology 269, 160–
169.
human risk
impact
assessment,
product
stewardship and
stakeholder
risk/benefit
communication
of nanomaterials
NanoCelluComp
The development
of very highperformance
bioderived
composite
materials of
cellulose
nanofibres and
polysaccharides
SunPap
Scale-up
Nanoparticles in
modern
papermaking
Work Package 4 Life cycle Analysis: Comparison of products
based on nanomaterials with conventional products in
order to illustrate their risks and benefits for the
environment. Determination of the environmental and
socio-economic impact of these products.
2011-03-012014-02-28
2009-07-012012-09-30
http://www.nanocellucomp
.eu
http://sunpap.vtt.fi
The aim of NanoCelluComp is to develop a technology to
utilise the high mechanical performance of cellulose
nanofibres, obtained from food processing waste streams,
combined with bioderived matrix materials, for the
manufacture of 100% bio-derived high performance
composite materials that will replace randomly oriented
and unidirectional glass and carbon fibre reinforced
plastics.
The environmental sustainability benefits and risks will be
quantified throughout the full product life cycle for selected
products, where the new material may substitute for carbon
fibre reinforced plastics and glass fibre reinforced plastics.
Environmental health and safety issues will be considered
for the full product life cycle of the selected products.
SunPap aims to strengthen the European paper industry’s
competitiveness by means of nanocellulose based
processes to provide radical product performance
improvements, new efficient manufacturing methods and
the introduction of new added value functionalities.
LCA was used to assess the environmental impact of Nano
fibrillated cellulose coated board, compared to
conventional board.
68
Hohenthal et al. 2012. Final assessment
of nano enhanced new products. VTT
APPENDIX B
Figure B.1: European Commission, Joint Research Centre, Institute for Environment and Sustainability,
Life Cycle Thinking and Assessment
Source: European Commission, 2010. Life Cycle Thinking and Assessment - Our thinking - life cycle thinking.
Available: http://lct.jrc.ec.europa.eu/index_jrc [Accessed: 20/03/2013]
Figure B.2: Joint Research Centre, Institute for Environment and Sustainability
Source: European Commission, n.d. Joint Research Centre, Institute for Environment and Sustainability, Life Cycle
Thinking and Assessment. Available: http://ies.jrc.ec.europa.eu/our-activities/support-for-eu-policies/life-cyclethinking-and-assessment.html [Accessed: 20/03/2013]
69
Figure B.3: United States Environmental Protection Agency
Source: United States Environmental Protection Agency, n.d. Risk Management Sustainable Technology, Life Cycle
Perspective. Available: http://www.epa.gov/nrmrl/std/lifecycle.html [Accessed: 20/03/2013]
Figure B.4: Mobile phone life cycle
Source: UNEP/SETAC, 2009. Life Cycle Management: How business uses it to decrease footprint, create
opportunities and make value chains more sustainable. United Nations Environmental Programme/Society of
Environmental Toxicology and Chemistry - Life Cycle Initiative. P.4
70
Raw material
acquisition
Resources, e.g.
raw materials
energy
land resources
Processes
Transports
Manufacture
Use
Emissions to
Air
Water
ground
Waste
Management
Figure B.4: The life cycle model
Source: Baumann, H., Tillman, A.M., 2004. The Hitch Hiker’s Guide to LCA. Studentlitteratur, Lund. P. 20
Figure B.4: The life cycle perspective
Source: Rex, E., 2008. Marketing for Life Cycle Thinking. PhD Thesis. Environmental Systems Analysis. Department
of Energy and Environment, Chalmers University of Technology Göteborg, Sweden. Page 3
71