Richard Denison, Ph.D., is a Senior Scientist.
I hate to say it, but Friends of the Earth, Consumers Union, and the International Center for Technology Assessment (ICTA) have done a disservice to good science and policy with their new superficial report Manufactured Nanomaterials and Sunscreens: Top Reasons for Precaution. There are all kinds of legitimate safety questions yet to be answered about the use of nanoscale ingredients in sunscreens, a few of which are briefly discussed in the report. But virtually all of them apply equally to the alternative chemicals used in other sunscreens as well, a fact that the report's authors conveniently duck.
Instead, the authors cite the usual litany of effects seen in various studies of nanomaterials, most of them associated with inhalation or ingestion – exposure pathways the relevance of which they never question in their apparent haste to warn consumers off of applying nano-containing sunscreens to their skin. They cite the "small size" of nanomaterials as the driving concern, failing to recognize that the organic molecules used in other sunscreens are typically far smaller – not to mention specifically designed to be absorbed into the skin.
Like the authors, I'm all for thorough testing, labeling and demonstration of safety of nanoscale ingredients in sunscreens and other consumer products. But those needs extend well beyond nanoscale materials to all ingredients. A less selective rendition of the facts about the safety of sunscreens would better serve these causes – and consumer protection.