Just say no to sunscreen nanophobia!

This post was chosen as an Editor's Selection for ResearchBlogging.orgOnce again we’re at a pivotal point in human development, where a novel technology might allow us to improve the lot of millions, perhaps billions of people across the globe and yet activists are invoking the precautionary principle and informing consumers of the possible dangers therein. As happened with vaccines, nuclear energy, genetically modified crops, stem cells and cloning, and the whole of the chemical and pharmaceuticals industry, they talk of known unknowns, unknown knowns, unknown unknowns and the need to avoid any risk at any price.

The latest scare-mongering is in a similar vein and comes just as the Northern summer reaches its sunniest peak. Apparently some sunscreen manufacturers are already going “nano free” because of activist pressure despite the fact that there is scant evidence that any of the so-called nanoscopic ingredients in modern sunscreens cause any harm whatsoever, while they’re protecting you from harmful sun exposure. It’s odd isn’t it? The marketers and sunscreen and cosmetics manufacturers jumped on the nano bandwagon a decade ago claiming all kinds of miraculous effects for their supposedly new ingredients, and yet today, they’re shying away from them.

In a recent paper in the International Journal of Biomedical Nanoscience and Nanotechnology (2010, 1, 1, 87-94), a lawyer at Australian National University, in Canberra, discusses the issues surrounding nanoparticles and aggregated nanoparticles in sunscreen.

“Currently, no health technology regulator internationally specifies distinct safety regulations or requirements that must be met by manufacturers using ENPs [engineered nanoparticles] in sunscreens or other health products,” he says. However, earlier in his paper Thomas Faunce points out that there are no published research results to suggest adverse effects partly because nanoparticles in sunscreen preparations , specifically zinc oxide and and titanium dioxide while forming free radicals in sunlight undergo “minimal dermal absorption… below the dead and highly keratinised cells of the stratum corneum.”

Am I missing something here? The paper first says that there is no obvious mechanism to suggest any risk other than free radical formation (which is after all caused by the UV absorption) and then suggests we must invoke the precautionary principle just in case. But, why?

Faunce adds that, “No government has yet established regulation to allow the public to make informed choices through proper labelling”. But, I’d like to know what he means by proper labelling. A proper label would perhaps say something like

WARNING This product contains nanoparticles that will protect you from sunlight by absorbing the energy of UV radiation, will only be absorbed by the upper layer of dead skin cells and so should be perfectly safe

Faunce talks of a “significant breakthrough for campaigners against the unregulated use of nanoparticulate sunscreens”, but one has to wonder why anyone should care about campaigners who are basing their concerns on non-facts. So what if apparently iconic sunscreen brands are now touting the fact that they’re nano-free, they know how to follow the market. But, it now means that consumers are left with old school sunscreens. I remember writing for Chemistry and Industry magazine back in the 1990s about evidence that certain conventional sunscreen formulations carried with them a cancer risk because their ingredients were indeed absorbed into deeper layers of the skin, unlike the nanoparticulate formulations.

Faunce refers to the three-quarters of 68 sunscreen brands surveyed as refusing to disclose whether or not their formulations contain nanomaterials and others admitting as if they’re somehow on trial.

I asked nanotechnology expert Andrew Maynard Director of the Risk Science Center at the University of Michigan, to comment on this odd scenario regarding the safety of nano-sunscreens. He points out that Faunce’s article seems to be predominantly focused on the labelling issue and the consumer’s right to know. “This is tricky, as even though the evidence indicates nanomaterials in sunscreens is pretty much a non-issue, there is still a question mark over how consumers and regulators actually know what the active ingredient is,” he told Sciencebase. However, he emphasises that the current state of science strongly indicates that healthy skin is a good barrier against nanoparticle penetration.

Maynard would argue that accurate ingredient identification is important, irrespective of whether the scientific consensus indicates there is a health issue or not. “In the case of nanoparticles in sunscreens, the evidence is strong that there is not a health issue,” he adds. ” Although, as always, there is a little wriggle room for doubt as the research isn’t 100% conclusive – once more a case of more research to dot the i’s and cross the T’s than taking action!” he adds.

Anyway, who said size doesn’t matter? Professor Tilman Butz, who has researched nanoparticle penetration through the skin and is the project leader of the (now complete ) EU Nanoderm Project, posted on Maynard’s blog suggesting that nanoparticles currently used are simply a non-starter when it comes to health issues with sunscreen:

In use are titanium dioxide and sometimes zinc oxide with primary particle sizes around 20 nm. They have a weight in the order of 1 MDa (1 million Daltons = weight of 1 million hydrogen atoms, expressed in molecular terminology although the particles are not molecules). There is general agreement that 0,5 kDa is the upper limit for dermal penetration. Hence, these particles are much too large (heavy) for dermal penetration.

In a climate where cancer organisations are forever trying to convince to avoid sun exposure (that’s another story: skin cancer and sun exposures ), one really has to wonder at the sense of activists trying to get active and useful materials removed from products that are purely a lifestyle choice in the first place. It’s not as if the manufacturers are forcing toxic sunscreen down our throats as they did with melamine contaminant in China not so long ago.

As far as I can tell, nano-sunscreens are more protective and companies who laid their towel on the best loungers by the pool earliest are now back pedalling purely for marketing purposes not because of the precautionary principle or any shift in safety knowledge.

Research Blogging Icon Thomas Faunce (2010). Exploring the safety of nanoparticles in Australian sunscreens Int. J. Biomed. Nanosci. Nanotechnol., 1 (1), 87-94

8 thoughts on “Just say no to sunscreen nanophobia!

  1. @Eurail Who are *they” and what are they “telling” us about anything? Did you know paying too much attention to tabloid scaremongering can cause paranoid neuroticism?

  2. Makes you wonder what they will be telling us in 5 years about the products we have today that are supposedly the “good, safe’ stuff!

  3. Regarding environmental effects, I think the environmental impact of people jumping into jet aircraft to fly to sunny beaches is far greater than worrying about nanoparticles that probably do not persist on the nano scale once rubbed off in the sea or on the sand…

  4. RE: Am I missing something here?

    Activists reactions seem do seem overly sensitive, if the effects of nano-particles on humans is the only concern with sunscreen use. But what I missed from your article is the effects of this new technology on the environment: the seas, lakes, rivers, sands, marshes and wildlife. Excessive sunscreen use alone is a problem in many ecosystems frequented by large amounts of humans during certain seasons, without the addition of new unknown potentials for disruption.

    Is this a factor in any of these companies’ decisions to scale back nanoparticle use? Is there any research done on this? What’s even more interesting to me as a layperson: is there any government regulation requiring companies to think about their product’s effects on anything but their customers or consumers?

  5. I think the issue is that they are using the unique properties of the materials at the nano scale which aren’t exhibited at the larger scale – ie clearness – so the concern is that there are other properties which come with that, which may make using them at this scale less safe than previous. As you know much better than I, some materials become more volatile or more easily absorbed by our bodies at the nanoscale, or by virtue of their use more ubiquitous in the environment, so it’s is the new characteristics and the new usage which need to be understood and safety testing conducted.

    Yes agree that if the word ‘nano’ hadn’t been invented, it may have passed by unnoticed, but you can thank the scientists chasing funding for that! On the other hand, old materials used in a new way with new properties would always have been called something, though would perhaps have been the focus of more case by case scrutiny rather than blanket coverage.

    Prof Richard Jones of Univ Sheffield suggests an excellent ‘precautionary’ framework which would be very useful in either instance on Andrew Maynard’s blog: He suggests we consider:

    * what are the benefits that the new technology provides – what are the risks and uncertainties associated with not realising these benefits?
    * what are the risks and uncertainties attached to any current ways we have of realising these benefits using existing technologies?
    * what are the risks and uncertainties of the new technology?

    Read more: http://2020science.org/2010/07/18/the-safety-of-nanotechnology-based-sunscreens-some-reflections/#more-3444#ixzz0uVCfdW2u

  6. I wonder whether the companies are simply victims of naive marketing, they’re just zinc oxide and titania particles that happen to be in the nano range (which can be stretched to several hundred nanometres when it suits (grant applications etc). If nano hadn’t been a buzzword I suspect they would never have mentioned it and the perceived risks would never have changed.

  7. David, whilst I agree that there now appears to be little to concern us about nano sunscreens, most of this evidence is relatively recent, while nano sunscreens have been around for some time, some say up to 20 years. Until these studies were published there appeared to be little to go on in terms of judging safety, and even when published they are quite tricky to interpret effectively by the non-scientist which I concluded from Andrew’s comments. Before these studies all that the lay person and other non-experts had to go on was a widely voiced concern from scientists and others about the potential uncertainties around nano particles of all materials and companies telling us not to worry as they had it all covered. I don’t think it is surprising that non-expert stakeholders got concerned.

    I also agree that some stakeholders, and FOE is perhaps as guilty of this as many others, do choose their evidence to support their world view, which is also unhelpful for the public.

    However, what I would have really liked to see, instead of ranting from all sides (and sorry David, I am classing this contribution in that vein, a few too many sweeping statements!) was patient, easy to understand explanations, information clearly communicated by scientists and companies about the testing they have done to ensure these products are safe for us all, perhaps articles in the women’s mags or in supermarkets, with information about the science behind the nano sunscreens and why they are safe and an improvement. Not scientists scoring points by trying to make a splash with dubious extrapolations about research and companies remaining totally silent. Why is that so hard?

    Sometimes I think that the increasing lack of trust in business and science is richly deserved! Let’s hope it improves

  8. Reminds of the fear propagated in the 1800s of people dying from the awesome speed – much faster than horses – of the first steam trains. While this fear was proven to be unfounded, trains are safe, but not perfectly safe. We still have wrecks, occasionally. Nothing is 100% safe, and suggesting so would be reprehensible.

    The point is to present the science as it is available (incomplete and emergent – tomorrow we usually know more than today) and help the public make informed choices. Some take the risk, some don’t, and the experiment can continue.

    A better labeling could be

    USE CAUTION This product helps protect your skin from sunlight by absorbing the energy of UV radiation. Prolonged exposure or incomplete application on skin may negate protective effects. This product contains nanoparticles (around 20 nm). Scientific findings suggest particles of the specified size will only be absorbed by the upper layer of dead skin cells and not enter body circulation.

    Reading “primary particle sizes” I conclude that smaller particles may occur and some can get absorbed, so we are back at square one whether the perceived risk is big or small, but now it is up to the customer to decide and experiment. Until science brings more usable findings as I am sure will happen.

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