Editor's note: Following is a letter to the editor from the Friends of the Earth organization in response to the present article. In this letter, the FoE points to conflicts of interest the author has, which were in fact fully disclosed to Cosmetics & Toiletries but not included in the article. Readers are invited to participate in the debate on the Cosmetics & Toiletries magazine LinkedIn Group, or to send additional comments or questions to Cosmetics & Toiletries editors at CTEdit@allured.com.
Dear Mr. Falk, editor in chief,
I have just been alerted to a piece in the current Cosmetics & Toiletries (C&T) magazine about nanoparticles in sunscreen. The article specifically names Friends of the Earth and attempts to frame us as fear-mongers and dismiss our concerns about the use of nanomaterials in sunscreen. The author, Paul G. McCormick, has failed to disclose a serious conflict of interest. He is the patent holder for ZinClear IM—a nano sunscreen ingredient. He is also the founder and former CEO of Antaria, the company that markets the product.
[Editor's note: C&T was in fact aware of this potential conflict; as a general policy, this information was not included in the article.]
In the article, Mr. McCormick claims that “nanoparticulate titanium dioxide and zinc oxide are safe sunscreen additives.” Mr. McCormick is a materials scientist not a toxicologist, and has no expertise in this field. Furthermore, his views are not shared by the European Commission’s Scientific Committee on Consumer Safety (SCCS). The SCCS recently recommended that certain nano titanium dioxide (TiO2) ingredients not be used in sunscreen because they strongly react with sunlight to produce free radicals.1 The SCCS also recommended that nano TiO2 and nano zinc oxide (ZnO) not be used in powder or sprayable products because of the toxicity risk associated with inhalation.2 The European Chemical Agency (ECHA) is also currently reviewing the safety of titanium dioxide (including the nano form) because of concerns in may be harmful to the environment and human health.3
Nanoparticles are typically more reactive than bulk particles of the same chemicals because of their large relative surface area. Furthermore, nanoparticles of metal oxides such as titanium dioxide are large producers of free radicals, which can damage DNA and protein. The head of the Australian Government’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) Nanosafety division has warned that in a worst-case scenario, nano-ingredients in sunscreens could increase the risk of skin cancer.4
To give you some background, in July last year (2012), Friends of the Earth (FoE) lodged a complaint against Antaria with the Australian Competition and Consumer Commission. Antaria had been marketing its ZinClear IM product as non-nano and we argued it was a nanomaterial. Finally, in December last year (2012), Antaria admitted that its ZinClear IM product was in fact a nanomaterial but claimed that it was "safe" despite having no evidence to back up this assertion.
There are a large number of inaccuracies and unsubstantiated statements in Mr. McCormick’s piece regarding both the potential toxicity and extent of skin penetration of nano zinc oxide and titanium dioxide and the public response to nano-ingredients in sunscreen. For example, Mr. McCormick claims that “there is no substantiated evidence that zinc oxide or titanium dioxide nanoparticles penetrate the human skin.” Whilst most studies to date have found no, or limited, skin penetration by nano-ingredients, serious limitations in these studies preclude us concluding that skin absorption does not occur.
The European Union’s high level Scientific Committee on Consumer Products has warned that existing research into skin penetration by nano-ingredients is inadequate and that further studies “taking into account abnormal skin conditions and the possible impact of mechanical effects on skin penetration need to be undertaken.”5 A 2010 in vivo study found small amounts of zinc from sunscreen in the blood and urine of human trial participants.6 The study used live human volunteers and was carried out over five days, with follow-p testing for at least six days. The study was not able to show whether the zinc was absorbed in particle or ionic form, so this requires further research. A number of other studies have demonstrated that nanomaterials can penetrate the skin.
Furthermore, a recent study found that nano anatase titanium dioxide can damage the outer layers of the skin. The scientists concluded that this could increase skin permeability and allow the diffusion of unwanted chemicals or nanoparticles into the viable layers of the skin.7
Mr. McCormick’s claims that FoE’s campaign for the labelling and safety testing of nano-ingredients in sunscreen is undermining the confidence of the public in using sunscreens is also not borne out by the evidence. Furthermore, his claims that he is not aware of any deaths attributable to the use of sunscreen is disingenuous since there have been no epidemiological studies looking at the health impacts of using nano sunscreen.
Friends of the Earth is concerned that Cosmetics & Toiletries magazine allowed such an article to be published without checking Mr. McCormick’s background or allowing Friends of the Earth a right to reply. We are therefore requesting a right to reply to counter some of the damage done to our reputation by Mr. McCormick. We also request that you print a correction to the online version of the article and in the next print edition of Cosmetics & Toiletries magazine clearly identifying Mr. McCormick’s conflict of interest. If you have any questions please do not hesitate to contact me.
Nanotechnology Project Coordinator, Friends of the Earth