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Nanomaterials in Personal Care: Opportunities and Safety Considerations
By: Julian Hewitt and Mindy Goldstein, PhD
Posted: November 26, 2008, from the December 2008 issue of Cosmetics & Toiletries.
page 5 of 5
Trying to treat all nanomaterials as though they pose the same degree of risk is not a reasonable approach. Fine particle grades of TiO2 and ZnO have been used in cosmetic products for nearly 20 years and have been subjected to extensive safety testing, the results of which have been independently reviewed by regulatory bodies and other organizations. A comprehensive review of the safety studies on these materials was published in 2007.5 The current listing of TiO2 as a UV filter on Annex VII of the EU Cosmetics Directive is based on an extensive dossier on the various aspects of consumer safety with TiO2, submitted by the industry and carefully evaluated by the SCCNFP (predecessor of SCCP). The opinion adopted by the SCCNFP in October 2000 is publicly available.6
It has been speculated that nanoparticles in cosmetics may penetrate through the skin. This aspect has been the subject of many studies and the evidence shows that insoluble nanoparticles, such as those used in inorganic sunscreens, do not penetrate into or through human skin. Further, the industry submitted a review of recent literature on safety of nanomaterials in cosmetics, with special references to skin absorption and resorption of ultrafine TiO2, to SCCP in 2005. Several new studies further indicate that ultrafine TiO2 does not penetrate the skin. This lack of penetration into or through human skin by UV attenuation forms of TiO2 used in sunscreens, as well as the absence of any health risk, has been acknowledged by the German7 and Australian8 health authorities.
A variety of different types of nanomaterials are being used in personal care products. Speculation around the penetration of these materials through skin, and possible implications for human health, have resulted in the call for increased regulations on such products. However, each different type of nanomaterial should be considered on a case-by-case basis. The type that has received the most attention is that of inorganic sunscreens, with which there has been ongoing debate as to whether these materials really should be considered nanomaterials at all. Regardless, a large body of evidence is available that shows that inorganic sunscreens do not penetrate skin and are completely safe for topical use.
Acknowledgements: The author would like to thank his colleagues, Laurie Hughes, Lorna Kessell, Carole Tapley and Ian Tooley, for their invaluable contributions to this article.
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1. The Project on Emerging Nanotechnologies, Woodrow Wilson International Center for Scholars Web site, available at: www.nanotechproject.org/inventories/consumer/ (Accessed Oct 1, 2008)
2. Publically Available Specification Terminology for Nanomaterials PAS 136:2007, The British Standards Institution Web site, available at: www.bsigroup.com/upload/
standards%20&%20Publications/Nanotechnologies/PAS%20136.pdf (Accessed Oct 1, 2008)
3. G Mie, Phys. Lpz., 25:377 (1908)
4. JL Robb, LA Simpson and DF Tunstall, DCI magazine (Mar 1994)
5. GJ Nohynek, J Lademann, C Ribaud and MS Roberts, Grey goo on the skin? Critical Reviews in Toxicology, 37 251-277 (2007)
6. Opinion of the Scientific Committee on Cosmetic Products and Nonfood Products Intended for Consumers Concerning Titanium Dioxide Colipa S75, European Commission Web site, available at: europa.eu.int/comm/health/ph_risk/
committees/sccp/documents/out135_en.pdf (Accessed Oct 1, 2008)
7. Federal Institute for Risk Assessment (BfR) Web site, available at: www.bfr.bund.de (Accessed Oct 1, 2008)
8. Safety of sunscreens containing nanoparticles of zinc oxide or titanium dioxide, Australian Government Department of Health and Aging, Therapeutic Goods Administration (TGA) Web site, available at: www.tga.gov.au/npmeds/sunscreen-zotd.htm (Accessed Oct 1, 2008)