Citing research suggesting that some invisibly small engineered nanoparticles might pose health risks, a coalition of consumer and environmental groups petitioned the Food and Drug Administration yesterday to beef up its regulation of nanoparticle-containing sunscreens and cosmetics and recall some products.

The legal filing was synchronized with the release of a report by the environmental group Friends of the Earth that highlighted the growing number of personal care products with nano-ingredients, defined as smaller than 100-millionths of a millimeter. At least 116 such products are on the market, the report found.

"Scientific bodies are beginning to develop an understanding of the serious risks that may be associated with nanomaterials," said Joseph Mendelson, legal director of the Washington-based International Center for Technology Assessment, which spearheaded the FDA filing. "Every day, consumers are being asked to be a test market for some of those risks."

Nanotechnology encompasses a wide range of materials that, because of their small size, exhibit novel chemical or biological properties. Among the FDA-regulated products being sold are sunscreens containing titanium dioxide or zinc oxide nano-particles (which offer strong ultraviolet protection while remaining colorless) and cosmetics with nanoscale liposomes -- tiny chemical bubbles that deliver moisteners and other ingredients to the skin.

A number of animal studies have shown that at least some nano-particles can penetrate cells and tissues, migrate through the body and brain and cause biochemical damage. But whether nano-spiked cosmetics and sunscreens pose health risks remains largely unknown, pending completion of long-range studies recently begun by the FDA and other agencies.

An Australian government medical committee concluded this year that metal oxide nanoparticles in sunscreens mostly remain on the outer layer of skin, where DNA damage is not a big concern.

The FDA regulates sunscreens as nonprescription drugs and does not require extra safety tests specific for nanoparticles. The agency has little authority over cosmetics.

But John Bailey, a vice president at the Cosmetic, Toiletry and Fragrance Association, a trade group, said his level of confidence in the safety of those products is "very high."

"I think these are safe and very beneficial products," said Bailey, who oversaw the FDA's cosmetics program for a decade.

Asked why companies rarely release the results of their safety studies, Bailey said the information was generally proprietary -- as are the ingredients. "We really don't know much about what they're putting in, or the levels," he said. But companies have lots of incentive to make their products safe, he added.

Two years ago, Britain's Royal Society recommended that nano-products not be sold until they have undergone independent safety assessments and the results are made public. It also said that products containing engineered nano-particles should be labeled as such, a move the industry has opposed.

The FDA does not comment on legal challenges and has six months to respond to yesterday's petition.

(www.washingtonpost.com)