Uncertainties surrounding the use of nanoparticles in cosmetics made the news in the UK yesterday; this followed a press release from the consumer group Which? – Beauty must face up to nano. This is related to a forthcoming report in their magazine, in which a variety of cosmetic companies were asked about their use of nanotechnologies (I was one of the experts consulted for commentary on the results of these inquiries).
The two issues that concern Which? are some continuing uncertainties about nanoparticle safety and the fact that it hasn’t generally been made clear to consumers that nanoparticles are being used. Their head of policy, Sue Davies, emphasizes that their position isn’t blanket opposition: “We’re not saying the use of nanotechnology in cosmetics is a bad thing, far from it. Many of its applications could lead to exciting and revolutionary developments in a wide range of products, but until all the necessary safety tests are carried out, the simple fact is we just don’t know enough.” Of 67 companies approached for information about their use of nanotechnologies, only 8 replied with useful information, prompting Sue to comment: “It was concerning that so few companies came forward to be involved in our report and we are grateful for those that were responsible enough to do so. The cosmetics industry needs to stop burying its head in the sand and come clean about how it is using nanotechnology.”
On the other hand, the companies that did supply information include many of the biggest names – L’Oreal, Unilever, Nivea, Avon, Boots, Body Shop, Korres and Green People – all of whom use nanoparticulate titanium dioxide (and, in some cases, nanoparticulate zinc oxide). This makes clear just how widespread the use of these materials is (and goes someway to explaining where the estimated 130 tonnes of nanoscale titanium dioxide being consumed annually in the UK is going).
The story is surprisingly widely covered by the media (considering that yesterday was not exactly a slow news day). Many focus on the angle of lack of consumer information, including the BBC, which reports that “consumers cannot tell which products use nanomaterials as many fail to mention it”, and the Guardian, which highlights the poor response rate. The story is also covered in the Daily Telegraph, while the Daily Mail, predictably, takes a less nuanced view. Under the headline The beauty creams with nanoparticles that could poison your body, the Mail explains that “the size of the particles may allow them to permeate protective barriers in the body, such as those surrounding the brain or a developing baby in the womb.”
What are the issues here? There is, if I can put it this way, a cosmetic problem, in that there are some products on the market making claims that seem at best unwise – I’m thinking here of the claimed use of fullerenes as antioxidants in face creams. It may well be that these ingredients are present in such small quantities that there is no possibility of danger, but given the uncertainties surrounding fullerene toxicology putting products like this on the market doesn’t seem very smart, and is likely to cause reputational damage to the whole industry. There is a lot more data about nanoscale titanium dioxide, and the evidence that these particular nanoparticles aren’t able to penetrate healthy skin looks reasonably convincing. They deliver an unquestionable consumer benefit, in terms of screening out harmful UV rays, and the alternatives – organic small molecule sunscreens – are far from being above suspicion. But, as pointed out by the EU’s Scientific Committee on Consumer Products, there does remain uncertainty about the effect of titanium dioxide nanoparticles on damaged and sun-burned skin. Another issue recently highlighted by Andrew Maynard is the issue of the degree to which the action of light on TiO2 nanoparticles causes reactive and potentially damaging free radicals to be generated. This photocatalytic activity can be suppressed by the choice of crystalline structure (the rutile form of titanium dioxide should be used, rather than anatase), the introduction of dopants, and coating the surface of the nanoparticles. The research cited by Maynard makes it clear that not all sunscreens use grades of titanium dioxide that do completely suppress photocatalytic activity.
This poses a problem. Consumers don’t at present have ready access to information as to whether nanoscale titanium dioxide is used at all, let alone whether the nanoparticles in question are in the rutile or anatase form. Here, surely, is a case where if the companies following best practise provided more information, they might avoid their reputation being damaged by less careful operators.