The Environmental Working Group has a new database rating sunscreens on how well they work AND how hazardous their ingredients are. I've always felt like I had to balance exactly those two concerns, so it's awesome to be able to find sunscreens that work and are relatively safe.

Here's their list of best sunscreens . (You'll have to scroll down the page; the formatting is kind of messed up.) And here's the list of the worst. The database is also searchable.

The weird thing is that many of the top-rated products contain micronized titanium dioxide, which Consumer Reports recently issued a warning about. Among their concerns:

- Certain benign materials can become toxic when nanosized because microscopic particles tend to react more readily with human tissues and other substances. - Nanoparticles can enter the body and its vital organs, including the brain, much more easily than can larger particles. And some are now used in food additives, cosmetics, and other products that are ingested or applied directly to the skin.

EWG counters:

Many sunscreens contain nano-scale ingredients that raise potential concerns. Micronized and nano-scale zinc oxide and titanium dioxide in sunscreen provide strong UVA protection, and are contained in many of our top-rated products. Repeated studies have found that these ingredients do not penetrate healthy skin, indicating that consumers' exposures would be minimal. Studies on other nano-scale materials have raised concerns about their unique, toxic properties. FDA has failed to approve effective UVA filters available in Europe that, if approved here, could replace nano-scale ingredients.

I don't know where that leaves it, really. I guess I'll try to stay away from nano ingredients for now.

Update: Here's a handy card from The Green Guide outlining what to look for and avoid when shopping for sunscreens. And this blog recommends Jason's Chemical-Free SPF 30-plus Sunblock, which doesn't contain micronized versions of titanium or zinc oxide. They write:

I also recommend trying testers at the store: squeeze a bit of a mineral-based sunscreen on your arm-if it's white and doesn't turn transparent as you rub it on skin, it's not going to be easily absorbed. Jason's Chemical-Free easily passed that test.