[athena123]

More information than you probably wanted to know. I'm slightly concerned that this site doesn't seem to think that ANY chemical barriers are sound. This site also expresses a lot of concerns about micronized use of minerals, but who wants to put a heavy, occlusive white cream on their face that looks like a lifeguard's nose? Nevertheless, a great place to start your research and draw your own conclusions.
More Healthy Suntanning, Best Sunblockers, Suntan Vitamins, Skin Cancer and Chemical Sunscreens

Sun screens are a very controversial topic within the FDA as well. Because of the FDA, the term "sunblock" isn't supposed to be allowed, since nothing can truly BLOCK UVA/UVB rays, although physical screens like Titanium and Zinc do deflect. They're also trying to come up with a rating system that will more accuratel y reflect protection from UVA rays, which is a lot more complicated than UVB.

FDA proposes sunblock testinganother forum-another forum-another forumThe Washington Times, America's Newspaper

Very dry reading, Q&A from the FDA website: Questions and Answers on the 2007 Sunscreen Proposed Rule