A big debate over Nanoparticles.

A NONPROFIT ORGANIZATION is warning consumers to protect themselves and their families from potentially harmful substances lurking in their sunscreens.

Friends of the Earth has released Nanoparticles and Sunscreens: A Consumer Guide for Avoiding Nano Sunscreens, which includes information about the health and environmental risks that nanoparticles may pose. The guide also contains the results of a survey of sunscreen manufacturers that can help consumers choose which products to use.

"When people use sunscreen, they expect it to protect their skin from sun damage and the possibility of cancer. It is unacceptable for the government to allow the very products Americans buy to protect themselves to threaten their health," said Ian Illuminato, author of Friends of the Earth.

In contrast, the Cosmetic, Toiletry and Fragrance Association (CTFA) stresses the important health benefits microparticles can provide consumers.

"Nanoparticles in sunscreens are very small particles that have been reviewed and approved by the FDA. They have been used safely and effectively by consumers for decades to protect from harmful UV rays and to prevent skin cancer," said John Bailey, executive vice president for science at CTFA and former FDA official.

"Nanoparticle ingredients in personal care products sit on top of the skin and are used in small amounts," said Mr. Bailey.

However, Friends of the Earth disagrees. According to the company, problems associated with nanotechnology include DNA damage, change in the function of cells, and even cell death because they are absorbed by the body.

"The fact that companies won't even say what their sunscreens contain is a cause for concern," Mr. Illuminate said.

Nanoparticles in sunscreen have been found to have no correlation with sun protection, and are mostly used to enhance the aesthetics of the lotion, such as a transparent formula as opposed to opaque white, according to Friends of the Earth.

The CTFA refutes this claim. "These ingredients have properties that provide a greater degree of protection from the sun, are transparent when applied and aesthetically pleasing, and therefore encourage greater consumer acceptance," said Mr. Bailey.

Still, Friends of the Earth, along with the International Center for Technology Assessment (ICTA), have filed legal action against the FDA because the U.S. government does not have nanotechnology safety standards.