Tag Archives: titanium dioxide

Butterflies give and give; this time they inspire more green fuel production

Butterflies are proving to be quite generous as they inspire ideas for greater production of green fuels in addition to everything else they’ve inspired. From the March 26, 2012 news item on Nanowerk,

“We were searching the ‘art of blackness’ for the secret of how those black wings [from black butterflies] absorb so much sunlight and reflect so little,” Fan [Tongxiang Fan, Ph.D] explained.…

Fan’s team observed elongated rectangular scales arranged like overlapping shingles on the roof of a house. The butterflies they examined had slightly different scales, but both had ridges running the length of the scale with very small holes on either side that opened up onto an underlying layer.

The steep walls of the ridges help funnel light into the holes, Fan explained. The walls absorb longer wavelengths of light while allowing shorter wavelengths to reach a membrane below the scales. Using the images of the scales, the researchers created computer models to confirm this filtering effect. The nano-hole arrays change from wave guides for short wavelengths to barriers and absorbers for longer wavelengths, which act just like a high-pass filtering layer.

The group used actual butterfly-wing structures to collect sunlight, employing them as templates to synthesize solar-collecting materials. They chose the black wings of the Asian butterfly Papilio helenus Linnaeus, or Red Helen, and transformed them to titanium dioxide by a process known as dip-calcining. Titanium dioxide is used as a catalyst to split water molecules into hydrogen and oxygen. Fan’s group paired this butterfly-wing patterned titanium dioxide with platinum nanoparticles to increase its water-splitting power. The butterfly-wing compound catalyst produced hydrogen gas from water at more than twice the rate of the unstructured compound catalyst on its own.

This work was presented at the American Chemical Society’s 243rd annual meeting themed Chemistry of Life  in San Diego, California, March 25-29, 2012.

As I’ve noted previously, although that was specific to Morpho butterflies (my Feb. 14, 2012 posting), butterflies are being very generous with their intellectual property.

Unintended consequences: Australians not using sunscreens to avoid nanoparticles?

Friends of the Earth (FoE) Australia has waged a campaign against the use of nanosunscreens. It seems to have been somewhat successful but in a way that I imagine is upsetting. From the Feb. 9, 2012 news item on physorg.com,

The Cancer Council of Australia reports that we have one of the highest rates of skin cancer in the world, with over 440,000 people receiving medical treatment for skin cancers each year, and over 1,700 people dying of all types of skin cancer annually.

The survey of public attitudes towards sunscreens with nanoparticles, commissioned by the Australian Department of Industry, Innovation, Science, Research and Tertiary Education and conducted last month, showed that about 17% of people in Australia were so worried about the issue, they would rather risk skin cancer by going without sunscreen than use a product containing nanoparticles. [emphasis mine] [please see correction at the end of this posting]

The survey along with three research papers were presented at the 2012 International Conference on Nanoscience and Nanotechnology (ICONN) in Perth,Feb. 5-9.

One of the research studies indicates that claims of  ‘nano-free’ sunscreen products may be wrong, from the Feb. 9, 2012 news item on Nanowerk,

Scientists from Australia’s National Measurement Institute and overseas collaborators reported on a technique using the scattering of synchrotron light to determine the sizes of particles in sunscreens. They found that some commercial sunscreens that claim to be ‘nano-free’ do in fact contain nanostructured material. The findings highlight the need for clear definitions when describing nanomaterials.


The Australian Therapeutic Goods Administration has released a statement on safety of sunscreens containing nanoparticles that concluded: “… the current weight of evidence suggests that TiO2 (titanium dioxide) and ZnO (zinc oxide) nanoparticles do not reach viable skin cells, rather, they remain on the surface of the skin and in the outer layer of the skin…”

You can get more information about the studies in either linked news item. The Australian government’s sunscreen use survey is available on this page; the Australian Therapeutic Goods Administration review of the scientific literature on the safety of nanoscale (nanoparticulate) titanium dioxide and zinc oxide in sunscreens is available on this page; and the Cancer Council of Australia has information about sunscreens and nanoparticles on this page.

One can’t lay the blame for *13%* of the population’s hesitance to use any sunscreens at one door but I hope that civil societies like FoEAustralia will give a little thought to the unintended consequences of their campaigns.

The campaign was against nanosunscreens not all sunscreens but presumably coupled with other influences, it seems to have upset a significant percentage of the population to the point that they refuse to use any sunscreens at all for fear of inadvertently being exposed to nanoparticles.

Feb. 10, 2012 update: It’s a very interesting response from FoEAustralia (from the Feb. 10, 2012 article by Simon Lauder for ABC  [Australian Broadcasting Corporation] News),

“We’ve decided to recall the safe sunscreen guides that we have produced this summer until we can revise them based on new information that comes in,” Elena McMaster, the nanotechnology campaigner with Friends of the Earth, said.

“What we see with this research is that in the absence of government regulation, the nanotech industry is able to more or less make up their own rules about what constitutes a nano material,” she said.

“We are obviously probably as shocked as people in the industry about the NMI research results.

“I can’t emphasise enough how urgent we think it is that the Government regulates.”

The best FoEAustralia can offer in the face of the rather shocking information that 17% of the adult population are avoiding sunscreens altogether is a plea for more government regulation of a product that doesn’t seem to be dangerous according to research.

Dexter Johnson in his Feb. 10, 2012 Nanoclast posting noted this about the study which found that sunscreens claiming ‘no nanomaterials/nanoparticles’ did contain some,

“What we see with this research is that in the absence of government regulation, the nanotech industry is able to more or less make up their own rules about what constitutes a nano material,” said Elena McMaster, a FoE spokesperson.

That’s one interpretation, I suppose. But it could also be that traditional sunscreens might contain nanoscale particles even though no attempt had been made to manufacture or add them to the mix. Unintentional nanoparticles, if you will, not unlike those created when the tires of your car drive over the pavement.

I wonder what kind of government regulations the FoE will request. Will each container of sunscreen have to be opened and its contents examined with a scattering of synchrotron light to determine particle size?

In fact, there’s some evidence that nanoparticles are all over the place, some of them created by nature, from the May 11, 2012 article New Evidence for Natural Synthesis of Silver Nanoparticles on Nanowiki,

“this creates the idea that there may be some sort of natural cycle returning some of the ions to nanoparticles.” [said Robert MacCuspie at NIST {US National Institute of Standards and Technology}] It also helps explain the discovery, over the past few years, of silver nanoparticles in locations like old mining regions that are not likely to have been exposed to man-made nanoparticles, but would have significant concentrations of silver ions. [emphasis mine]

My respect for FoEAustralia is seriously damaged by this stance they’ve taken. As far as I’m concerned they should admit they’ve made a mistake by using scare tactics to force some sort of confrontation over nanosunscreens and their strategy to force regulation of nanomaterials has backfired seriously.

Feb.21.12 correction: According to the information in the Feb. 20, 2012 posting on 2020 Science, the percentage of Australians likely to avoid using sunscreens is 13%,

This has just landed in my email in box from Craig Cormick at the Department of Industry, Innovation, Science, Research and Tertiary Education in Australia, and I thought I would pass it on given the string of posts on nanoparticles in sunscreens on 2020 Science over the past few years:

“An online poll of 1,000 people, conducted in January this year, shows that one in three Australians had heard or read stories about the risks of using sunscreens with nanoparticles in them,” Dr Cormick said.

“Thirteen percent of this group were concerned or confused enough that they would be less likely to use any sunscreen, whether or not it contained nanoparticles, putting them selves at increased risk of developing potentially deadly skin cancers.

“The study also found that while one in five respondents stated they would go out of their way to avoid using sunscreens with nanoparticles in them, over three in five would need to know more information before deciding.”

*’17%’ corrected to ‘13%’ on Sept. 22, 2016.

New research on nanoscale titanium dioxide shows toxic effects on marine life

Up till now, nanoscale titanium dioxide in water has not been viewed as toxic to marine life. A newly released study by researchers from  the University of California (UC) Center for Environmental Implications of Nanotechnology (UC CEIN) in the Jan. 20 in the journal PLoS ONE suggests otherwise. From the Jan. 24, 2012 news release on EurekAlert,

“Previous experiments have suggested that TiO2 does not affect aquatic organisms, but these experiments used artificial lighting that generated much lower levels of UVR than sunlight,” Miller [lead author and assistant research biologist Robert Miller] explains. “In these new experiments, we used lights simulating natural sunlight.”

But now, the authors say, “We show that relatively low levels of ultraviolet light, consistent with those found in nature, can induce toxicity of TiO2 nanoparticles to marine phytoplankton, the most important primary producers on Earth.

So, the relatively low levels of ultraviolet light in natural sunlight can induce toxicity in titanium dioxide nanoparticles. Here’s the reason for the concern,

“Application of nanomaterials in consumer products and manufacturing is quickly increasing, but there is concern that these materials, including nanoparticles, may harm the environment,” says Miller. “The oceans could be most at risk, since wastewater and factory discharges ultimately end up there.”

In all of the kerfuffle that the Friends of the Earth (FoE) and The ETC Group (and I assume others as well) have made over nanoscale ingredients in sunscreens they seem to have ignored the impact that these ingredients, when washed off our skin and into our water supply, may have on aquatic life.  I wonder if that will matter in the end. I mean if it turns out that nanoscale titanium dioxide is going to kill/damage “… the most important primary producers on Earth”, does it matter if FoE and the others succeed in mobilizing opposition to its use for what most experts might consider the wrong reasons.

Self-cleaning clothes

There’s a new cotton fabric that will self-clean when exposed to sunlight. From the Dec. 14, 2011 news item on Nanowerk,

Mingce Long and Deyong Wu say their fabric uses a coating made from a compound of titanium dioxide, the white material used in everything from white paint to foods to sunscreen lotions. Titanium dioxide breaks down dirt and kills microbes when exposed to some types of light. It already has found uses in self-cleaning windows, kitchen and bathroom tiles, odor-free socks and other products. Self-cleaning cotton fabrics have been made in the past, the authors note, but they self-clean thoroughly only when exposed to ultraviolet rays. So they set out to develop a new cotton fabric that cleans itself when exposed to ordinary sunlight.

Their report describes cotton fabric coated with nanoparticles made from a compound of titanium dioxide and nitrogen. They show that fabric coated with the material removes an orange dye stain when exposed to sunlight. Further dispersing nanoparticles composed of silver and iodine accelerates the discoloration process. The coating remains intact after washing and drying.

It’s nice to see that the coating doesn’t wash or dry off easily. Long’s and Wu’s report appears in the ACS [American Chemical Society] Applied Materials & Interfaces (“Realizing Visible-Light-Induced Self-Cleaning Property of Cotton through Coating N-TiO2 Film and Loading AgI Particles”).  Mingce Long is from the  School of Environmental Science and Engineering, Shanghai Jiao Tong University, China  and Deyong Wu is from the School of Chemical and Environmental Engineering, Hubei University for Nationalities, China.

Dexter Johnson of the Nanoclast blog on the IEEE website (Institute of Electrical and Electronics Engineers) notes this in his Dec. 22, 2011 posting,

… This is not just cotton treated with TiO2 but cotton treated with a mix of silver iodide (Agl) along with Nitrogen (N)-TiO2. This combination increased the photocatalytic activities of the material.

So, this is what I find so infuriating about coverage of nanotechnology. Couldn’t someone (besides me) have said that researchers had found a way of improving the photocatalytic performance of TiO2 in textiles so as to make their self-cleaning properties X times better than previous methods?

There you have it from an engineer who’s been the nanotech scene for quite some time. The concept of coating a textile with nanoscale titanium dioxide so it self-cleans is not new; the discovery in this case is a refinement which increased the photocatalytic properties of the textile in question.

Brain injuries in fish and nanoparticles?

I would have liked more details about the fish and how nanoparticles cause brain injuries. Here’s an excerpt from the Sept.19, 2011 news item on Nanowerk,

Scientists at the University of Plymouth have shown, for the first time in an animal, that nanoparticles have a detrimental effect on the brain and other parts of the central nervous system.

They subjected rainbow trout to titanium oxide [or titanium dioxide as it’s sometimes called] nanoparticles which are widely used as a whitening agent in many products including paints, some personal care products, and with applications being considered for the food industry. They found that the particles caused vacuoles (holes) to form in parts of the brain and for nerve cells in the brain to die. Although some effects of nanoparticles have been shown previously in cell cultures and other in vitro systems this is the first time it has been confirmed in a live vertebrate.

I have a number of questions after reading this (and the rest of the news item).

  • The statement is that nanoparticles cause brain injury in fish but the researchers mention titanium di/oxide nanoparticles only.  Did they test other nanoparticles as well?
  • How did they conduct the tests?
  • Did the fish ingest titanium di/oxide from the water? From their food? From both?
  • What concentrations were they exposed to?
  • Were they in an environment similar to what they’d experience naturally? Or were they in special tanks?

Apparently the results are being presented in London at the “6th International meeting on the Environmental Effects on Nanoparticles and Nanomaterials” (21st – 23rd September [2011]) at the Royal Society.

Using an incendiary headline (Nanoparticles cause brain injury in fish) for your news release is certainly an attention getter. I trust the research team (led by Professor Richard Handy of the Plymouth University Ecotoxicology Research and Innovation Centre’s Environmenal nanoscience and nanotoxicology team) can back up this statement with data and that it will be made available to a broader audience than the meeting attendees.

Slime, titanium dioxide, and marine ecosystems

I have wondered what happens when titanium dioxide nanoparticles in sunscreens wash off. Apparently, I’m not alone. Two scientists in Connecticut are studying marine biofilm (the slimy green stuff) found on rocks and docks at the seaside. According to a news item on Nanowerk,

While swimmers and boaters along any shore consider the slimy green film that coats everything from rocks to docks as a nuisance, University of New Haven (UNH) chemical engineering student Nicole Reardon and Assistant Professor Shannon Ciston, Ph.D. think otherwise. They view the slime, or biofilm, as a complex community that may hold the key to informing humanity of the true environmental impact of the chemical nanoparticles that find their way from area kitchens, baths and garages into Long Island Sound. One such controversial compound is titanium dioxide, which is used to whiten and brighten a multitude of products, including candy, cosmetics, toothpaste and paint.

… Noting that “large” particles of titanium dioxide are considered safe by the FDA, Ciston and Reardon are interested in how nanoparticles of titanium dioxode affect marine ecosystems, particularly in terms of the humble biofilm. Reardon explains that while marine biofilms can be a bother, they are critical players in the oceanic environment. In addition to transforming nitrogen and carbon in ways that positively impact the greater food web, biofilms clean waste water by eating harmful organic matter and can even be used to clean oil and gasoline spills through bioremediation.

I was hoping to find more information about this project on the University of New Haven website but they appear to have sent out a news release only.  Unfortunately, Dr. Shannon Ciston’s webpage doesn’t offer any additional insight and I could not find a webpage for graduate student Nicole Reardon. My guess is that the lack of more information is due to the University of New Haven being a small university with limited resources. Bravo to their communications team for getting this project noticed and I hope to hear more about it as it progresses.

Nanomaterial use in construction, in coatings, in site remediation, and on invisible planes

Next to biomedical and electronics industries, the construction industry is expected to be the most affected by nanotechnology according to a study in ACS (American Chemical Society) Nano (journal). From the news item on Azonano,

Pedro Alvarez and colleagues note that nanomaterials likely will have a greater impact on the construction industry than any other sector of the economy, except biomedical and electronics applications. Certain nanomaterials can improve the strength of concrete, serve as self-cleaning and self-sanitizing coatings, and provide many other construction benefits. Concerns exist, however, about the potential adverse health and environmental effects of construction nanomaterials.

The scientists analyzed more than 140 studies on the benefits and risks of nanomaterials. …

The article in ACS Nano is titled, “Nanomaterials in the Construction Industry: A Review of Their Applications and Environmental Health and Safety Considerations.

Still on the construction theme but this time more focused on site remediation, here’s a story about sulfur-rich drywall which corrodes pipes and wiring while possibly causing respiratory illness. From the news item on Nanowerk,

A nanomaterial originally developed to fight toxic waste is now helping reduce debilitating fumes in homes with corrosive drywall.

Developed by Kenneth Klabunde of Kansas State University, and improved over three decades with support from the National Science Foundation, the FAST-ACT material has been a tool of first responders since 2003.

Now, NanoScale Corporation of Manhattan, Kansas–the company Klabunde co-founded to market the technology–has incorporated FAST-ACT into a cartridge that breaks down the corrosive drywall chemicals.

Homeowners have reported that the chemicals–particularly sulfur compounds such as hydrogen sulfide and sulfur dioxide–have caused respiratory illnesses, wiring corrosion and pipe damage in thousands of U.S. homes with sulfur-rich, imported drywall.

“It is devastating to see what has happened to so many homeowners because of the corrosive drywall problem, but I am glad the technology is available to help,” said Klabunde. “We’ve now adapted the technology we developed through years of research for FAST-ACT for new uses by homeowners, contractors and remediators.”

The company has already tested its new product and found that corrosion was reduced and odor levels dropped to almost imperceptible. There are plans to use the company’s technology in the Gulf Coast and elsewhere there are airborne toxic substances.

In Europe, Germany has plans to introduce new concrete paving slabs that reduce the quantity of nitrogen oxide in the air. From the news item on Nanowerk,

In Germany, ambient air quality is not always as good as it might be – data from the federal environment ministry makes this all too clear. In 2009, the amounts of toxic nitrogen oxide in the atmosphere exceeded the maximum permitted levels at no fewer than 55 percent of air monitoring stations in urban areas. The ministry reports that road traffic is one of the primary sources of these emissions.

In light of this fact, the Baroque city of Fulda is currently embarking on new ways to combat air pollution. Special paving slabs that will clean the air are to be laid the length of Petersberger Strasse, where recorded pollution levels topped the annual mean limit of 40 micrograms per cubic meter (µg/m3) last year. These paving slabs are coated with titanium dioxide (TiO2), which converts harmful substances such as nitrogen oxides into nitrates. Titanium dioxide is a photocatalyst; it uses sunlight to accelerate a naturallyoccurring chemical reaction, the speed of which changes with exposure to light.

They’ve already had success with this approach in Italy but Germany has fewer hours of sunshine and lower intensities of light so the product had to be optimized and tested in Germany. Testing has shown that the effect for Germany’s optimized paving slabs does not wear off quickly (it was tested again at 14 months and 23 months). Finally, there don’t seem to be any environmentally unpleasant consequences. If you’re curious about the details, do click on the link.

One last item, this time it’s about a nano-enabled coating that’s a paint. An Israeli company has developed a paint for airplanes that can make them invisible to radar. From Dexter Johnson’s July 14, 2010 posting on Nanoclast,

No, we’re not talking about a Wonder Woman-type of invisible plane, but rather one that becomes very difficult to detect with radar.

The Israel-based Ynetnews is reporting that an Israeli company called Nanoflight has successfully run a test on dummy missiles that were painted with the nano-enabled coating and have shown that radar could not pick them up as missiles.

The YnetNews article rather brutally points out that painting an aircraft with this nanocoating is far cheaper than buying a $5 billion US-made stealth aircraft. Of course, it should also be noted that one sale of a $5 billion aircraft employs a large number of aeronautical engineers, and the high price tag also makes it far more difficult for others to purchase the technology and possess the ability to sneak up on an enemy as well.

You can read more and see a picture of Wonder Woman’s invisible plane by following the link to Dexter’s posting.

Regulating nanomaterials according to the US GAO and EPA

It’s been a banner week for information about nanomaterials regulation. As I noted yesterday, the US General Accountability Office has just released its  report titled Nanotechnology: Nanomaterials Are Widely Used in Commerce, but EPA Faces Challenges in Regulating Risk. Hats off to the authors: Anu Mittal, lead author, and Elizabeth Erdmann, David Bennett, Antoinette Capaccio, Nancy Crothers, Cindy Gilbert, Gary Guggolz, Nicole Harkin, Kim Raheb, and Hai Tran.

In discussing some of the oversight and regulatory issues associated with nanotechnology and other emerging technologies they had this to say (from the report),

Nanotechnology is an example of a fast-paced technology that poses challenges to agencies’ policy development and foresight efforts. We have conducted past work looking at the challenges of exercising foresight when addressing potentially significant but somewhat uncertain trends,5 including technology-based trends that proceed at a high “clockspeed,” that is, a (1) faster pace than trends an agency has dealt with previously or (2) quantitative rate of change that is either exponential or exhibits a pattern of doubling or tripling within 3 or 4 years, possibly on a repeated basis.6 As our prior work has noted, when an agency responsible for ensuring safety faces a set of potentially significant high-clockspeed technology-based trends, it may successfully exercise foresight by carrying out activities such as

• considering what is known about the safety impact of the trend and deciding how to respond to it;

• reducing uncertainty as needed by developing additional evidence about the safety of the trend; and

• communicating with Congress and others about the trends, agency responses, and policy implications.

Similarly, our 21st Century Challenges report raised concern about whether federal agencies are poised to address fast-paced technology-based challenges. [GAO, 21st Century Challenges: Reexamining the Base of the Federal Government, GAO-05-325SP (Washington, D.C.: February 2005)] Other foresight literature illustrates the potential future consequences of falling behind a damaging trend that could be countered by early action. These analyses suggest that unless agencies and Congress can stay abreast of technological changes, such as nanotechnology, they may find themselves “in a constant catch-up position and lose the capacity to shape outcomes.” (p.7/8 print version, p. 11/2 PDF)

(Seems to me the Canadian government could also do with some thoughtful consideration of fast-changing technologies and the challenges they pose to the institutional oversight mechanisms currently in place.)

The report goes on to describe various nano-enabled product categories in various industry sectors. It’s an overview that includes products (e.g. nano-enabled cell phones) currently or soon-to-be on the market. I was particularly taken with an image of a cell phone  that tagged parts  already nano-enabled (on some models) along with parts that may, in the future, become nano-enabled (p. 14 print version or p. 18 PDF).

The toxicity roundup is one of the best presentations I’ve seen. For example,

  • Size. Research assessing the role of particle size on toxicity has generally found that some nanoscale (<100 nanometers) particles are more toxic and can cause more inflammation than conventionally scaled particles of the same composition. Specifically, some research indicates that the toxicity of certain nanomaterials, such as some forms of carbon nanotubes and nanoscale titanium dioxide, may pose a risk to human health because these materials, as a result of their small size, may be able to penetrate cell walls, causing cell inflammation and potentially leading to certain diseases. For example, the small size of these nanomaterials may allow them to penetrate deeper into lung tissue, potentially causing more damage, according to some of the studies we reviewed. In addition, some nanomaterials may disperse differently into the environment than conventionally scaled materials of the same composition because of their size. However, according to EPA, the small particle size may also cause the nanomaterials to agglomerate, which may make it more difficult for them to penetrate deep lung tissue. (pp. 23/4 print version, pp. 27/8 PDF)

This a much more measured but still cautious approach to the toxicology issues as they relate to size and this approach is maintained throughout.

There’s more than one way to be exposed,

In addition to toxicity, the risk that nanomaterials pose to humans and the environment is also affected by the route and extent of exposure to such materials. Nanomaterials can enter the human body through three primary routes: inhalation, ingestion, and dermal penetration. (p. 25 print version, p. 29 PDF)

They also make the distinction between exposure as a consequence of consuming products and exposure due to occupation.

Moving on from toxicity, their section on the international scene wowed me because this is the only report I’ve seen which notes that Canada’s nanomaterials inventory has yet to occur.

One thing I hadn’t realized was how similar Environment Canada’s and the US Environmental Protection Agency’s approach to nanomaterials has been. From my April 2, 2010 posting,

Here’s what Environment Canada has to say about nanomaterials (the information on this page is dated from 2007 …) NOTE: The page originally cited is no longer available, go to this page,

The Domestic Substances List (DSL) is the sole basis for determining whether a substance is new. Any chemical or polymer not listed on the DSL is considered to be new to Canada and is subject to the notification requirements under the Regulations. Substances listed on the DSL do not require notification1 in advance of manufacture in or import into Canada.

The Act and the Regulations apply to new nanomaterials just as any other substance, whether a chemical or a polymer.

Substances listed on the DSL whose nanoscale forms do not have unique structures or molecular arrangements are considered existing. Existing nanomaterials are not subject to the Regulations and do not require notification. For example, titanium dioxide [emphasis mine] (CAS No. 13463-67-7) is listed on the DSL and since its nanoscale form does not have unique structures or molecular arrangements, it is not subject to the Regulations.

Compare,

In its 2008 document, EPA stated that a nanomaterial is a new chemical for purposes of regulation under TSCA only if it does not have the same “molecular identity” as a chemical already on the inventory. Under TSCA, a chemical is defined in terms of its particular molecular identity.

Thus, because titanium dioxide is already listed on the TSCA inventory, nanoscale versions of titanium dioxide, which have the same molecular formula, would not be considered a new chemical under TSCA, despite having a different size or shape, different physical and chemical properties, and potentially different risks. [emphasis mine] (p. 34 print version, p. 38 PDF)

I gather the EPA adopted the strategy one year after Environment Canada. Given how often the various jurisdictions copy each other’s approaches, I wonder which country (or possibly a jurisdiction such as the European Commission) actually set this strategy.

The report offers an excellent summary of Canada’s current regulatory approach and plans. I’ve reproduced the passage in full here,

Canadian officials have proposed but have not implemented a one-time requirement for companies to provide information on nanomaterials produced in or imported into Canada. Canadian importers and manufacturers would be required to report their use of nanomaterials produced or imported in excess of 1 kilogram. In 2009, Canadian officials reported to the OECD that information required would include chemical and trade name; molecular formula; and any available information on the shape, size range, structure, quantity imported or manufactured, and known or predicted uses. Also required would be any available information on the nanomaterial’s physical and chemical properties—such as solubility in water and toxicological data, among others. Under the proposal, companies could claim information as confidential, but regulators would publish a summary of information provided. Canada plans to use this information to help develop a regulatory framework for nanomaterials and to determine which information requirements would be useful for subsequent risk assessments. Canadian officials stated they originally hoped to issue this requirement in the spring of 2009 but could not predict when it would be implemented.

With regard to current law, a report prepared for the government of Canada in 2008 stated that Canada has no specific requirements for nanomaterials and is considering whether they are needed. However, Health Canada and Environment Canada—two agencies responsible for health and the environment—have taken the first steps in recognizing the potentially unique aspects of nanomaterials. These regulatory agencies are currently relying on existing authority delegated to them through legislation, such as the Canadian Environmental Protection Act, to address nanomaterials. Specifically, in June 2007, Environment Canada released a new substances program advisory announcing that nanomaterials will be regulated under the act’s new substances notification regulations. Per this advisory, any nanomaterial not listed on Canada’s chemical inventory—the Domestic Substances List—or with “unique structures or molecular arrangements” compared to their non-nano counterparts, requires a risk assessment. A review panel of the Canadian Academies found that, while it is not necessary to create new regulatory mechanisms to address the unique challenges presented by nanomaterials, the existing regulatory mechanisms could and should be strengthened in a variety of ways, such as by creating a specific classification for nanomaterials and by reviewing the regulatory triggers that prompt review of the health and environmental effects. (pp. 45/6 print version, pp. 49/50 PDF)

As far as I’m aware, there are no comparable summaries available in Canadian reports available to the public. No doubt there are nits to be picked but all I can say is thank you for giving me the most comprehensive and succinct overview I’ve seen yet of the emerging Canadian regulatory framework for nanomaterials.

For interested parties, there is some additional information about Health Canada’s public consultation on their interim definition of nanomaterials in my April 28, 2010 posting.

Not enough data to assess risk for nanoscreens?

I’m glad to see that the Friends of the Earth (FOE) civil society group (or nongovernmental agency) have responded to Andrew Maynard’s challenge. As I thought, the FOE has stated that it is impossible to assess the risk that nanoscreens (specifically the sunscreens’ titanium dioxide and/or zinc oxide nanoparticles) present as there is not enough data.

The statement (posted in a June 15, 2010 posting on the 2020 Science blog) was made in response to a challenge by Dr. Andrew Maynard (blog owner) first issued in his June 8, 2010 posting (Friends of the Earth come down hard on nanotechnology – are they right?) and further detailed in another June 8, 2010 posting (Just how risky could nanoparticles in sunscreens be?).

FOE goes on to detail some of the problems associated with providing an answer (you can view the full statement in the first link provided in the second paragraph),

Andrew – thanks for the invitation to perform some complex risk assessment using several poorly understood variables. However we do have to point out that the world’s best minds don’t yet have enough information even to design reliable nanomaterial risk assessment processes, let alone to come up with a single ‘worst case scenario’ figure for long term health impacts of using nano-sunscreens.

The huge knowledge gaps plaguing nanomaterials toxicity and exposure assessment (along with preliminary studies suggesting the potential for serious harm) are key reasons for calls by Friends of the Earth Australia and United States for a precautionary approach to management of nanotoxicity risks.

I don’t think the sarcasm with which the authors (Georgia Miller and Ian Illuminato) open their statement is absolutely necessary but their main point is well made as it opens the door to a discussion about one’s perspective on and philosophy towards risk.

The impact that engineered nanoparticles of any kind could have on life is poorly understood and research is urgently needed. The research that has been undertaken on titanium dioxide and zinc oxide nanoparticles does suggest some potentially serious problems could occur. I want to emphasize my phrasing here ‘could occur’ because to date we have no evidence that anyone using nanoscreens has had any health issues as a consequence of their use. Still, the laboratory research is concerning. So, how are we as a society and as individuals going to approach the risk?

The school of thought which supports the FOE’s application of the precautionary principle seems to be that any element of risk should curtail use until the engineered nanoparticles have been extensively tested and then declared safe. I’m not clear how testing under those conditions could ever proceed to human clinical trials. It would not be possible to test every single variable or, more importantly, every combination of variables which could result in a risk. The net result would be: no nanoscreens while people use possibly inferior to nanosunscreen products to protect themselves from the sun’s effects.

I’ve commented about the Environmental Working Group (EWG) and their assessment of nanosunscreens previously (here). Last year (2009), they, reluctantly, after an extensive meta analysis of the available research recommended nanosunscreens on the basis that there was no compelling data to suggest undue risks. The EWG has not adjusted its stance since then and, this year, are warning against sunscreens that use Vitamin A and oxybenzone as well as sunscreens that are applied in spray or powder forms.

In most circumstances I imagine that the FOE and the EWG would be natural allies as both NGOs are focused on health and safety issues. So it’s strange that the FOE did not mention the EWG report (as I noted here) in the FOE’s own 2009 report on sunscreens although they did cite research from Japan that supports the FOE’s position but was released after the EWG’s 2009 recommendations.

In the instance of nanosunscreens, there appears to be a sharp division of opinion between the two groups. I think this points to a major philosophical difference in their approaches to risk. Faced with identical (or almost so) data sets, the FOE wants to halt use until these nanoparticles are declared safe while the EWG suggests that these nanosunscreens might be safer than conventional products currently in the marketplace and recommends their use.

The approach as exemplified by the FOE is to insist on extensive testing and guarantees as to how and when nanotechnology-enabled products are safe before they ever get near the marketplace. This is the precautionary principle being applied. Given the complex environment we all navigate on a daily basis, I can certainly understand the stance. However, I am pragmatic by nature and since testing every single possible variable and combination of variables is impossible I am more inclined to consider the data that we currently have available as inconclusive. I have read some (not all) of the materials and I’ve noticed that the scientists’ conclusions are always expressed in very measured tones.

To illustrate my point about the “measured tones”, I’ve excerpted this from FOE’s response to Andrew’s challenge in the June 15, 2010 posting on 2020 Science,

FOE: Transparent micron-particle sized zinc oxide sunscreens are commercially available; a recent article suggests most titanium dioxide nano-sunscreens on the market could be doing more harm than good. No-one need use nanoparticles in order to produce a cosmetically and functionally acceptable sunscreen.

The article is in Nature Nanotechnology (behind a paywall) and it’s the published version of Dr. Amanda Barnard’s work using a computer simulation to establish potential toxicity. From the Nature Nanotechnology article,

… using this technique [computer simulation] it is possible to draw direct comparisons between the SPF, transparency and potential toxicity of nanoparticles used in sunscreens, based on fundamental nanoscale properties, and optimize these parameters numerically. In general, optimization decisions of this type are usually based on product testing under expected usage conditions, but the results presented here do complement traditional product and consumer testing activities, and can also be applied to other thermal or chemical conditions, or applied to any other material where a trade-off is necessary when balancing efficacy, aesthetics and an undesirable side effect. [emphases mine]

I gather Dr. Barnard is viewing the use of a computer simulation in research as a complement and not as a replacement for or an equivalent to traditional testing. In an interview with Anna Salleh for the Australian Broadcasting Corporation Science Online website,

Dr Barnard found that the size and concentrations of nanoparticles that gave the best transparency and sun protection also gave the highest potential for production of free radicals.

“Where we have the highest sun-protection factor – and it’s pretty – it [the sunscreen] is also toxic, potentially,” she said.

“Ultimately we have to trade off. We can’t have our cake and eat it too.”

I’m not sure what sort of trade-off Dr. Barnard might be suggesting but it’s clear that she’s aware that the use of nanotechnology-enabled products such as nanosunscreens is not a simplistic ‘good (conventional sunscreens) vs. bad (nanosunscreens)’ situation.

Dexter Johnson makes note of the FOE’s response to Andrew’s challenge in his essay (Daring to Challenge NGOs on Nanotech Risk) on the Nanoclast blog with some pithy and thought-provoking comments.

I do have one major point of difference with Dexter, I find the FOE’s suggestion that the companies selling the nanosunscreen products should provide their testing information to be a good idea although I first saw it in a comment from Hilary Sutcliffe in the comments section of one of Andrew’s June 8, 2010 postings.

I do believe that NGOs are important players in the debate but the tenor of the FOE’s response to Andrew’s challenge makes it a little harder to hold on to that belief. From the June 15, 2010 posting on Andrew’s blog,

Andrew, we respectfully suggest that someone of your expertise and stature could play a more constructive role in these debates – debates which should not be limited to a question of technical risk assessment. [emphasis mine]

I think the challenge was very constructive indeed.

I did comment on this latest sunscreen discussion last week, Part 1 and Part 2 where I discuss the nature of risk, uncertainty and nanosunscreens.