To the Editor: More than 1000 sunscreen products are marketed in Australia, and an increasing proportion (about one-third) incorporate engineered nanoparticles (ENPs). Defined as manufactured particles having one or more dimensions less than 100 nm (0.00001 cm), ENPs exploit the altered chemical reactivity and other changes that reduction to nanosize elicits. ENPs in sunscreen, such as titanium dioxide (TiO2) and zinc oxides, constitute effective broad-spectrum ultraviolet radiation (UVR) blocking agents with enhanced cosmetic transparency. The Australian Therapeutic Goods Administration (TGA), in approving such products, has stated that “there is no evidence that sunscreens containing these materials pose any risk to the people using them”.1 Similarly, authors of a recent article (written in collaboration with representatives of a cosmetic company) interpret the evidence as confirming that ENPs do not penetrate below the stratum corneum, or only in small amounts, producing limited cellular toxicity.2 Information on sunscreen packaging is not required to disclose the presence of ENPs.
- 1. Therapeutic Goods Administration. Safety of sunscreens containing nanoparticles of zinc oxide or titanium dioxide. Canberra: TGA, 2006. http://www.tga.gov.au/npmeds/sunscreen-zotd.htm (accessed Dec 2009).
- 2. Nohynek GJ, Lademann J, Ribaud C, Roberts MS. Grey goo on the skin? Nanotechnology, cosmetic and suncreen safety. Crit Rev Toxicol 2007; 37: 251-277.
- 3. Hirakawa K, Mori M, Yoshida M, et al. Photo-irradiated titanium dioxide catalyzes site specific DNA damage via generation of hydrogen peroxide. Free Radic Res 2004; 38: 439-447.
- 4. Baker PJ, Branch A. The interaction of modern sunscreen formulations with surface coatings. Prog Org Coatings 2008; 62: 313-320.
- 5. Faunce TA, Murray K, Nasu H, Bowman D. Sunscreen safety: the precautionary principle, the Australian Therapeutic Goods Administration and nanoparticles in sunscreens. NanoEthics 2008; 2: 231-240.
- 6. Friends of the Earth. Nanotechnology project. http://nano.foe.org.au/node/286 (accessed Jan 2009).
- 7. New South Wales Government Standing Committee on State Development. Nanotechnology in New South Wales. Sydney: NSW Government, 2008. http://www.parliament.nsw.gov.au/prod/PARLMENT/committee.nsf/0/35D2E3E3749 8A908CA2574F1000301BB (accessed Jan 2009).
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