Don't celebrate right away if you've spent a day at the beach without getting burned: Some sunscreens may actually cover up redness, leading the people who use them to spend even more time in the sun, further exposing themselves to cancer-causing UV rays.
The Environmental Working Group is concerned that anti-inflammatory and antioxidant ingredients in sunscreen may hide a sunburn, the initial signs of skin damage. In a letter to the Food and Drug Administration, the group asked the agency to investigate these ingredients. EWG also called on the FDA to finalize a rule that would cap SPF labels at 50.
Here's the EWG's letter. And here's its list of recommended sunscreens.