Some of the world's most prestigious cosmetic houses have been accused by an environmental group of using Australian women as guinea pigs.
The cosmetic industry says the controversial use of nanoparticles is not widespread. But an independent analysis by Friends of the Earth, which has described nanoparticle cosmetics as the 21st-century equivalent of lead and arsenic face powders, found nanomaterials in all 10 randomly selected foundations.
The brand names included Revlon, Clarins, L'Oreal, Yves Saint Laurent, Clinique, Lancome and Max Factor. Only one product, a Christian Dior foundation, declared the presence of nanoparticles on its label.
The Friends of the Earth's national co-ordinator for nanotechnology, Georgia Miller, said the results, from the Australian Microscopy and Microanalysis Research Facility, showed the use of nanoparticles was much more widespread than the industry would have people believe.
Moreover, seven of the 10 products also contained "penetration enhancers", ensuring the nanoparticles could reach beyond the superficial skin layers, enter the bloodstream and be absorbed by organs and tissues.
The cosmetic industry's peak body, ACCORD, has dismissed the study. The association's director of policy, Craig Brock, criticised its failure to state the percentages of the nanoparticles found.
"It's a bit like testing a food for cholesterol and then not saying what the percentage is," he said. "These products are safe for use. Their ingredients simply do not penetrate beyond the outer layers of the skin."
But Thomas Faunce, of the Australian National University, who holds an Australian Research Council fellowship to examine public health issues associated with nanotechnology, said the study's findings were significant and strengthened the case for mandatory labelling and that stringent safety data should be required from manufacturers.
"Research is showing that nanoparticles have the capacity to damage living cells and the precautionary principle should be applied," he said.
Earlier this year, the European Union passed laws which will require all cosmetics and sunscreens using nanomaterial derived from existing chemicals to be individually tested for safety before being released on the market by 2012. No such testing is required in Australia and the labelling of nanoparticles in cosmetics is not mandatory.
Only the Therapeutic Goods Administration has power to regulate cosmetics if they have an SPF of 15 or higher. Cosmetics without an SPF rating are regulated by the National Industrial Chemicals Notification and Assessment Scheme.
Earlier this month the scheme began a series of public consultations after the release of a discussion paper on regulatory reform of industrial nanomaterials.