Aug 21 2009
One of the harshest critics of industry on the issue of nanomaterial safety – the Environmental Working Group (EWG), a US-based NGO that works to expose threats to health and the environment - came to a "surprising" conclusion: Sunscreens containing nanomaterials are among the most effective and safest on the market.
Two years earlier, a Consumers Union investigation found that many sunscreen products claiming to be "nano-free" actually contained manufactured nanoparticles of zinc and titanium oxide. Friends of the Earth in 2007 published a consumer guide to avoid nano-sunscreens which has been updated in July 2009. All of these prior publications on the issue of nanoparticles in sunscreens had in common that they presumed the use of nanoparticles to be dangerous (however, sometimes based on rather weak scientific arguments) and recommended not using such products.
EWG took a more comprehensive approach in testing over 1600 sunscreen products and evaluating over 400 peer-reviewed studies on nanomaterials in sunscreens. In their evaluation, EWG not only looked at whether or not products provide broad-spectrum UV protection, but also at which sunscreens break down in the sun, and at the full range of potentially hazardous sunscreen ingredients that can absorb through the skin and into the body to pose other risks. The researchers found that out of 1671 sunscreens on the market, 3 out of 5 either don’t protect the skin from sun damage or contain hazardous chemicals. The results are summarised in a database and a report.
The investigation also included sunscreens containing nanoscale titanium dioxide and zinc oxide. According to the report, consumers who use sunscreens without zinc and titanium are likely exposed to more UV radiation and greater numbers of hazardous ingredients than consumers relying on zinc and titanium products for sun protection.
A review of 16 studies on skin absorption of zinc oxide and titanium dioxide nanoparticles revealed that nearly all studies showed no absorption of small-scale zinc and titanium sunscreen ingredients through healthy skin. On balance, EWG researchers found that zinc and titanium-based formulations are among the safest, most effective sunscreens on the market based on available evidence.
On the other hand, for nano-scale ingredients, the NGO called for full labelling so consumers can make informed choices. And, in the sense of a precautionary approach, they only recommend using nano sunscreens if the nanomaterial brings a clear advantage: "If it's not protecting your health, don't use it".
Contact & more information: Markus Widmer
Source: The Innovation Society