March, 2014 Jennifer Sass, NRDC Lauren Heine, Clean ... · Jennifer Sass, NRDC . Lauren Heine,...
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"Utility of the Greenscreen® for Safer Chemicals for nanoscale hazard assessment: nanosilver case study" March, 2014 Jennifer Sass, NRDC Lauren Heine, Clean Production Action
Transcript of March, 2014 Jennifer Sass, NRDC Lauren Heine, Clean ... · Jennifer Sass, NRDC . Lauren Heine,...
"Utility of the Greenscreen® for Safer Chemicals for nanoscale hazard assessment:
nanosilver case study"
March, 2014
Jennifer Sass, NRDC Lauren Heine, Clean Production Action
Goal: Moving to Safer Ingredients and Driving Transparency
In the absence of mandatory product labeling, public debate or laws to ensure their safety, products created using nanotechnology have entered industries, workplaces, and consumer markets. "We currently know very little about nanoscale materials' effect on human health and the environment. The same properties that make nanomaterials so potentially beneficial in drug delivery and product development are some of the same reasons we need to be cautious about their presence in the environment"
— Linda Birnbaum, Ph.D., director of NIEHS and the NTP
Can We Use the GreenScreen (GS) to Assess Nanomaterials?
Goal - Test the GS as a vehicle to gather and communicate hazard information on nanomaterials Approach - Convene a prominent group of independent scientific experts to: Define scope of nanomaterials and studies to assess; (size distribution, shape, structure charge, coating, surface chemistry, agglomeration/aggregation, etc); Recommend relevant modifications to the GS method. Apply the GS to selected nanomaterials (use independent contractor, NSF) Review results with scientific experts and NGOs
Presenter
Presentation Notes
What is the GreenScreen®? • A method for comparative Chemical Hazard Assessment (CHA)
developed by the NGO Clean Production Action • Allows you to compare chemicals based on hazard in a
comprehensive and consistent framework – a level playing field • Builds on the USEPA DfE approach and other national and
international precedents (OECD, GHS) • Free and publicly accessible, transparent and peer reviewed • Considers 18 environmental and human health endpoints • Addresses constituents and breakdown products • Evaluates hazards for an overall chemical score (Benchmark)
All supporting resources at: http://www.cleanproduction.org/Greenscreen.v1-2.php
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Presenter
Presentation Notes
GS assesses chemicals according to eighteen hazard endpoints (including chronic and acute toxicity, ecotox, and physical characteristics such as flammability and reactivity), scores each endpoint according to the available data or identifies a data gap, and then uses this information to assign a Benchmark score (BM) from 1 to 4, with 1 being the most hazardous.
GreenScreen Adoption
• Corporate materials selection (HP) • Corporate policies (Staples) • State regulations (ME, WA) • Ecolabels and standards (USGBC LEED v4) • Alternatives assessments
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GS builds on the US EPA Design for the Environment (DfE) approach, along with global OECD Globally Harmonized System (GHS) and other accepted systems. The use of comparative chemical hazard assessments can support informed decision making by regulators, policymakers, product designers and chemists.
18 Hazard Endpoints Human Health
Group I Human Health Group II
and II* Environmental Toxicity & Fate
Physical Hazards
Carcinogenicity
Acute Toxicity
Acute Aquatic Toxicity
Reactivity
Mutagenicity & Genotoxicity
Systemic Toxicity & Organ Effects
Chronic Aquatic Toxicity
Flammability
Reproductive Toxicity
Neurotoxicity Other Ecotoxicity studies when
available
Developmental Toxicity
Skin Sensitization Persistence Respiratory Sensitization
Endocrine Activity Skin Irritation Bioaccumulation
Eye Irritation
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Assign a level of concern for each hazard endpoint e.g. carcinogenicity (H, M or L)
Make Informed Decisions • Know what you know, and what you don’t know • Benchmarks provide a simple 1-4 score that supports taking action
– BM1 – avoid/phase out – BM2 – manage, to use safely – BM3 – getting there – BM4 – inherently low hazard
• Can be used by non experts in toxicology to support product design, policies and regulations 7
Presenter
Presentation Notes
GS assigns a Benchmark score (BM) from 1 to 4, with 1 being the most hazardous. Where there are no data for an endpoint, GS can use analogs, modeled data, or other available reasonable substitutes to inform that endpoint. Confidence in the score is identified as high (a bold letter), low (an italics), or very poor (DG, data gap). Chemicals that are carcinogens, mutagens, reproductive and developmental toxicants, endocrine disruptors, and PBTs (persistent, bioaccumulative, and toxic) would be considered substances of high concern, with a BM 1.
Nano Silver
Applications for nanosilver: • Coatings: for food packaging, food cutting boards, clothing, films,
fabrics • Medical: wound dressing, dental hygiene, and treatment of eye
conditions and other infections • Water treatment processes: surface coatings, including washing
machines and paints – leads to significant silver discharge
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Presentation Notes
Materials 2013, 6, 2295-2350; doi:10.3390/ma6062295 Mechanisms of Silver Nanoparticle Release, Transformation and Toxicity: A Critical Review of Current Knowledge and Recommendations for Future Studies and Applications Bogumiła Reidy 1,*, Andrea Haase 2, Andreas Luch 2, Kenneth A. Dawson 1 and Iseult Lynch 1,3
The specific materials evaluated for this case study were nanoscale metallic silver, a nano silica-silver nanocomposite, and conventional silver (dispersed low-solubility dispersed silver and silver salts). The extent of nanoscale test material characterization was considered in assessing the adequacy of the studies used.
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GreenScreen DRAFT Results - nanosilver Route GreenScreen™Hazard Ratings: Dispersed (low-solubility, non-nanoscale) silver - Benchmark Score of 1 based on combined very High
Persistence coupled with very High Ecotoxicity, as determined in standardized tests.
Group I Human Group II and II Human Ecotox Fate Physical
C M R D E AT ST N
SnS SnR IrS IrE AA CA P B RX F Single Repeated Single Repeat
ed
Oral DG
L
DG DG
DG
L DG DG DG DG
L DG L L vH vH vH L L L Dermal DG DG DG L DG DG DG DG Inhalation DG DG DG DG DG DG DG DG
Route GreenScreen™Hazard Ratings: Nanosilver, metallic - Benchmark Score of 1 based on very High Persistence coupled with High systemic toxicity and very High Ecotoxicity.
Group I Human Group II and II Human Ecotox Fate Physical
C M R D E AT ST N
SnS SnR IrS IrE AA CA P B RX F Single Repeated
Single Repeated
Oral DG
L
DG DG
DG
L DG M DG DG
L DG L L vH vH vH L DG DG Dermal DG DG DG L DG DG DG DG Inhalation DG DG DG vH DG H DG DG
Route GreenScreen™Hazard Ratings: AGS-20 (silver-silica nanocomposite containing 19.3% silver nanoparticles imbedded in a matrix of amorphous silicon dioxide) - Benchmark Score of U (unspecified) based on numerous datagaps.
Group I Human Group II and II Human Ecotox Fate Physical
C M R D E AT ST N
SnS SnR IrS IrE AA CA P B RX F Single Repeated
Single Repeated
Oral DG
DG
DG DG
DG
L DG DG DG DG
L DG L M DG DG vH DG L L Dermal DG DG DG L DG DG DG DG Inhalation DG DG DG M DG DG DG DG
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Presentation Notes
Both silver and nanoscale silver were classified as BM1 (highest concern), based primarily on high aquatic toxicity, persistence, and acute inhalation toxicity for nanosilver (for conventional silver, there were no data on this endpoint). The silica-nanosilver composite, a form recently conditionally approved by EPA for use in textiles as an antimicrobial agent, was unassigned (BM Unspecified (U)) due to data gaps. The form of these materials mattered more than size for acute inhalation hazard, where nanosilver was much more hazardous than the silica-nanosilver composite, likely because there is more silver in the nanosilver than in the composite. For eye irritation hazard the form also influenced the outcome, with the reverse result that the silica-nanosilver composite was more hazardous than both the nanosilver and conventional silver, with the latter two being about equal. In this case, the larger size of the composite (micron scale) may be driving its irritation hazard. For aquatic toxicity, size matters in that particle aggregation reduced the hazard, likely by reducing surface area and thereby reducing reactivity of the silver. This suggests that high aquatic hazards may be mitigated if the bioavailability of the material is reduced in natural waters, for example by agglomeration or by product design to reduce the release of silver ion from products such as textile products. The EPA approval of AGS-20 was based in part on the assumption that toxicity is governed by Ag+ ions, thus silver nitrate could be used as an analog to fill data gaps. This GS did not use silver nitrate as an analog to fill datagaps, because the point of the screen was to examine particle size-specific hazards. There are scientific justifications for both positions. Note: Exposure routes include Oral (o), Dermal (d), and Inhalation (i). Hazard levels are Very High (vH), High (H), Moderate (M), Low (L), and Very Low (vL)). Italics reflects estimated values and lower confidence, as with data gaps (DG), whereas BOLD font reflects values based on test data (see guidance). Endpoints include Carcinogenicity (C), Mutagenicity / Genotoxicity (M), Reproductive Toxicity (R), Developmental and/or Neurodevelopmental Toxicity (D), Endocrine Activity (E), Acute Mammalian Toxicity (AT), Systemic Toxicity – Single Exposure (ST-single) or Repeated Exposure (ST-Repeated), Neurotoxicity – Single Exposure (N-single) or Repeated Exposure (N-Repeated), Skin Sensitization (SnS), Respiratory Sensitization (SnR), Irritation/Corrosivity – Skin (IrS), Irritation/Corrosivity – Eyes (IrE), Acute Aquatic Toxicity (AA), Chronic Aquatic Toxicity (CA), Persistence (P), Bioaccumulation (B), Reactivity (Rx), and Flammability (F).
Summary of DRAFT GS Results • Both silver (dispersed) and nanoscale (metallic) silver were
classified BM1 (highest concern benchmark score) – aquatic toxicity, persistence and acute inhalation toxicity
• Silica-nanosilver composite (AGS-20) unassigned (U) due to data gaps
• Acute inhalation hazard – form matters – Nanosilver >>Silica-nanosilver composite
• Eye irritation hazard – form matters – Silica-nanosilver composite > nanosilver = silver
• Aquatic toxicity – size matters – Particle aggregation reduced acute aquatic toxicity
Methods of Silver Incorporation Into
Fabrics – not all products are alike
Reidy et al, 2013.
Presenter
Presentation Notes
Mechanisms of Silver Nanoparticle Release, Transformation and Toxicity: A Critical Review of Current Knowledge and Recommendations for Future Studies and Applications Bogumiła Reidy, Andrea Haase, Andreas Luch, Kenneth A. Dawson and Iseult Lynch Materials 2013, 6, 2295-2350; doi:10.3390/ma6062295
Challenges of Engineering Nanomaterials – What is It, Really?
• Institutes like Safer Nanomaterials and Nanomanufacturing Initiative (SNNI) in Oregon work to develop more benign ways to produce and use nanomaterials because of the challenge of engineering known quantities – What is the range of size, shape, etc. produced? – Different sizes and shapes can have different toxicities
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Presentation Notes
Some of the challenges and limitations for the GS when assessing nanomaterials include: each nanomaterial may represent different substances whereas conventional chemicals are a single entity with a unique CAS#; nanomaterials are characterized by at least ten physical-chemical properties that can influence hazard, whereas conventional particulate chemicals are characterized by four; it’s unclear whether data from standardized test protocols are always appropriate for nanomaterials; the “dose-response” for nanomaterials may be better reflected by alternative metrics, such as surface area or particle number, rather than by mass; the current state of knowledge of nanomaterial toxicology is too limited to reliably use analogs and predictive models to fill data gaps.
Principles for the Oversight of Nanotechnologies and Nanomaterials (NanoAction 2007)
1. A precautionary foundation 2. Mandatory nano-specific regulations 3. Health and safety of the public and workers 4. Environmental protection 5. Transparency 6. Public participation 7. Inclusion of broader impacts 8. Manufacturer liability
http://www.centerforfoodsafety.org/files/final-pdf-principles-for-oversight-of-nanotechnologies_80684.pdf
Conclusions
• It is possible to use comparative hazard assessments such as GreenScreen and existing toxicology today – to see what we know and what we do not know (i.e., data gaps)
• Ensure nanomaterials are screened before they are introduced in food & other products: – require assessment and public disclosure of results
by businesses, NGOs and public sector – regulate and require transparency about
nanomaterial use in specific products
Presenter
Presentation Notes
GreenScreen™ hazard assessment of silver and nanosilver demonstrates what we know, what we don't, and what we'd like to know before we get too cozy with nanomaterials. Jennifer Sass’s blog. June 11, 2013 Available at: http://switchboard.nrdc.org/blogs/jsass/greenscreen_hazard_assessment.html
CORPORATE NANO POLICIES NIKE sportswear nano policy (2007/2011) . Nike, currently restricts their use “to ensure that any potentially negative impacts to consumers and the environment, associated with the use of nanomaterials, are minimized, if not eliminated”. GlaxoSmithKline nano policy (2013). Defines nanomaterials and summarizes regulatory positions globally. It confirms using nano TiO2 in sunscreens, and nano in vaccines. McDonald’s and Kraft have nano policies stating that they do not use nanomaterials in food, packaging, or toys. But, they are researching it for future possible uses.
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Presentation Notes
Going public on nanomaterials�Chemical Watch. Global Business Briefing, March 2014 / Multinational bodies ��Concerns about possible health and environmental effects, together with a general lack of knowledge about which products contain nanomaterials, has pushed some EU member states to require firms to report information to national inventories of nanomaterial-containing products, and the European Commission is considering whether an EU register is necessary or desirable (CW 29 October 2013 <http://chemicalwatch.com/17011/eu-commission-under-fire-for-slow-progess-on-nano> ). But it is not easy to find many examples of companies that have published details of how they use nanomaterials or clear corporate policies on the issue.��Sportswear manufacturer, Nike, first published a policy on its use of nanomaterials in 2007. Most recently updated in 2011, its corporate nanotechnology material guidelines <http://www.nikeincchemistry.com/wp-content/uploads/Nanotechnologies-Policy.pd> include a definition of the term “nanomaterials” and, says Nike, currently restricts their use “to ensure that any potentially negative impacts to consumers and the environment, associated with the use of nanomaterials, are minimised, if not eliminated”. The statement sets out the conditions that must be fulfilled before a nanotechnology can be used within a Nike product, such as compliance with global legislation, proven effectiveness and a consistent toxicity review to ensure safety. ��'Commitment to transparency'��Nike says it established the policy as part of its “commitment to transparency” rather than in response to concerns from investors or other stakeholders. In 2007, “awareness among consumers and regulators was limited and we wanted to let them know that we had taken risks posed by nanotechnology into account”. The company says it works with an independent toxicologist to review the use of all nanomaterials used in its products.��One of the most prevalent issues is the use of nano-film technology which is applied on top of materials, says the company. In total, “there is very little use of nanomaterials in our products,” states Nike. But despite its support for transparency, it declined to specify where its uses them. ��The public statement <http://www.gsk.com/content/dam/gsk/globals/documents/pdf/Nanomaterials.pdf> by pharmaceutical giant, GlaxoSmithKline (GSK), on its use of nanotechnology, published in March 2013, is more detailed than Nike’s. It sets out a definition of nanomaterials, GSK’s position and use of the technology, as well as a summary of the regulatory position in different geographical regions. The company says the statement demonstrates its “transparency around public policy issues” and, like Nike, that it was not established because of concerns from consumers or investors about use of the technology.��The statement confirms the use of nano-sized titanium dioxide in a few sunscreen products marketed by GSK’s consumer healthcare business. It also highlights the use of nanotechnology in its vaccines, in particular of “nanoliposomes and nanoemulsions to improve the solubility, bioavailability, safety and effectiveness of our vaccines or to enhance their stability”. GSK currently markets no pharmaceutical products that contain deliberately engineered nanomaterials, but the company says it is “actively investigating” opportunities in this field. ��Some leading global food companies, such as McDonald’s and Kraft, have also drawn up publicly available statements on nanomaterials – to state that they are not using the technology. McDonald’s short statement <http://www.aboutmcdonalds.com/mcd/sustainability/library/policies_programs/sustainable_supply_chain/product_safety/Nanotechnology.html> , on which it declined to expand, says it is “working to understand the use of nanotechnology and its application in food and packaging products”. It adds: “Given the current uncertainty related to potential impacts of nano-engineered materials, McDonald’s does not currently support the use by suppliers of nano-engineered materials in the production of any of our food, packaging and toys.”��Kraft gives a slightly longer explanation <http://www.kraftfoodsgroup.com/DeliciousWorld/food-safety-quality/nanotech.aspx> of its position. While it currently does not use nanotechnology, it says it wants to understand the technology’s potential “in terms of food safety, product quality, nutrition and sustainability”. In particular, it is looking at the technology as a potential way to produce packaging that requires less material and that, therefore, helps to reduce waste. “If we ever intend to use nanotechnology, we will make sure that the appropriate environmental, health and safety concerns have been addressed,” it says.��Nanomaterials use is not an investment issue'��Some major brands, such as Adidas, do not publish statements on nanomaterials. It says it only uses the technology “in very single cases,” such as its golf shoes coated with a nano-scale polymer waterproof layer. The “few existing scientific studies on natural nanoparticles have proved to be insufficient in regard of human risk scenarios and possible environmental impact of the fast growing number of industrial nano-applications”, says the company, and it is monitoring the science “in close consultation with scientific experts and critical stakeholders”. But from an investment point of view, it says, nanomaterials are not an issue, because for shareholders “the use of nanomaterials does not seem to be a matter of concern”.��Monitoring the nanotechnology debate��Retailer Marks & Spencer (M&S), which has strongly promoted its ”Plan A” <http://plana.marksandspencer.com/> sustainability initiative, also has no official position. It says it would “only use nanotechnology where there is a proven customer benefit, and where we know it is safe to use. At the moment, it is not in any M&S food or drink products and we only use it in some M&S beauty products, something that is commonplace in the cosmetics industry.” It says it will “continue to monitor the debate on nanotechnology and talk to our customers on the issue”. The retailer has no statistics to share on what its consumers think about nanomaterials, but says that although it talks to its investors regularly about Plan A and other relevant issues, “nano is not an issue they’ve raised to date”. ��Clothing retailer H&M, recently rated by Greenpeace as a leader in its efforts to eliminate hazardous chemicals from its supply chain (CW 6 November 2013 <http://chemicalwatch.com/17142> ), also has no official policy on nanomaterials – although it does have one banning antibacterial treatments, including nanosilver, in finished products, and restricts the use of some nanomaterials in cosmetic products. ��Another household name, Ikea, does not publish a corporate policy, but “keeps a neutral and flexible approach towards nanotechnology as we acknowledge the complexity of this issue”. It says it “constantly monitors legal requirements, and in the absence of these we set our requirements based on precautionary considerations.”��Swiss Re, one of the world’s largest reinsurers, “would welcome the development and communication of nano policies of companies because we think it would increase transparency of the use of nanotechnology,” says Roland Friedli, senior risk engineer at Swiss Re corporate solutions. “He believes that a higher level of transparency regarding nanomaterials, such as declarations on products, could be beneficial “not just for consumers but also for insurance”. According to Mr Friedli, “insurers should have an interest in such information because it will enable them to assess the potential exposures more precisely”.��“A scheme reaching over all stages of the lifecycle of nanomaterials – including production, use and disposal – would, in our view, be seen as a good practice”, says Mr Freidli. Such a policy should not be limited to the manufacturing or marketing company, but should also include supply chains, although “setting up a meaningful and comprehensible declaration scheme by the manufacturing industry might be challenging”. ��Striking a balance between details and generalisation��The correct declaration of nanomaterials is challenging because standards and procedures for nanotechnology are not yet on a comparable level to chemicals, says Mr Friedli. This means that “defining and declaring nanomaterials is a difficult and rather complex task”. The need to declare several properties – including size and size distribution, surface properties, engineered versus naturally occurring nanomaterials, and agglomeration – in order to define a nanomaterial, adds to this challenge, he says.��Likewise, harmonised measurement procedures are not yet fully developed for nanomaterials, and certain measurements might not be comparable if one manufacturer uses different methods to other companies in the same field. “It is sometimes difficult to find a good balance between details and generalisation,” he adds. ��Mr Friedli says he has mixed feelings about placing the word “nano” on consumer good labels. Although such labels might generate interest among consumers, he says, they would not convey much information regarding issues such as the health impact of a nanomaterial. But the need to deal with nanomaterials is a real issue that companies need to tackle. They “are a real insurance risk, in particular because certain nanomaterials may hold some latent hazard that may have significant but delayed negative impacts that are difficult to identify and assess early on.”��To comment on this article, click here: Chemical Watch Forum <http://forum.chemicalwatch.com/>
NO CORPORATE NANO POLICIES, BUT USE NANO ADIDAS says it only uses the technology “in very single cases,” such as its golf shoes coated with a nano-scale polymer waterproof layer Marks & Spencer (M&S) says it would “only use nanotechnology where there is a proven customer benefit, and where we know it is safe to use. At the moment, it is not in any M&S food or drink products and we only use it in some M&S beauty products, something that is commonplace in the cosmetics industry.” H&M does not use nanosilver in its clothing, but does use nanomaterials in some cosmetic products. IKEA says it is neutral and flexible.
ACKNOWLEDGEMENT: We are grateful to CS fund for support to the Coming Clean Collaborative for this project. We are grateful to NSF International for conducting all DRAFT GreensSreens presented here. These are still in DRAFT phase and may be altered before being finalized.
