There was an email sent out at the hospital I work at, and it had some pretty interesting/scary information about Vitamin A, an ingredient found in 41% of sunscreens.
The FDA found the retinyl palmitate (a form of Vitamin A) can be photocarcinogenic-meaning it may speed the development of skin tumors and lesions when used in the presence inf sunlight NTP 2009). Right after I read this, I went right to my medicine cabinet and checked the label on all our sunscreens-and living in Southern California, we go thought a ton of sunscreen. Turns out all of our Banana Boat sunscreens have retinyl palmitate in them, BUT, they also carry the Skin Cancer Foundation seal of recommendation and are found on their list of recommended sunscreens.
Granted the FDA research is preliminary, and was conducted on lab animals, nonetheless the Environmental Working Group took the liberty of coming up with their own list of recommended sunscreens-which do NOT contain vitamin A, and a separate list of those that do, but are still decent sunscreens.
Also, be wary of sunscreens with exaggerated SPF ratings, which can be ploy to get the consumer to spend more cash, and also provides a false sense of security. Check out this article for more info on sunscreens and their ratings. And of course, there's an app for that. You can download and app for EWG's list of sunscreens right to your I-phone.