1. Things you want in your sunscreen: zinc oxide and titanium dioxide. They provide good protection against UVB (the radiation that causes sunburn) and UVA (rays that can suppress the immune system and damage the DNA of cells, causing premature aging and skin cancer).
2. Don't use spray sunscreens that contain zinc oxide and titanium oxide because the micronized particles may be absorbed through the lungs.
3. "Estrogenic" (steroid hormones) ingredients you don't want in your sunscreen: oxybenzophenone (or its derivatives BP-3 and oxybenzone), homosalate (HMS), 4-methyl-benzylidene camphor (4-MBC), octyl methoxycinnamate (OMC or octinoxate), octyl dimethyl paba (ODP) and parabens. A 2001 study published in Environmental Health Perspectives reported these chemicals may cause reproductive problems.
4. Carcinogens and hormone disruptors you don't want in your sunscreen: diethanolamine (DEA), triethanolamine (TEA), padimate O and salicylates.
5. A study from the Centers for Disease Control published in July 2008 found BP-3 in the urine of 96.8 percent of the 2,517 Americans 6 years and older who were tested, indicating it can be absorbed through the skin and into the bloodstream.
6. Avoid combination sunscreen/insect repellents. You need to reapply sunscreen often, but it isn't always safe to do so with insect repellents.
7. SPFs refer only to protection against UVB rays. UVA protection requires a "broad spectrum" sunscreen.
8. A comprehensive scientific review by the Environmental Working Group suggests 85 percent of the 993 sunscreen products it analyzed contain ingredients that pose safety concerns or offer inadequate protection from the sun.
9. The EWG has compiled a Sunscreen Safety Guide, which rates sunscreens, lip balms and moisturizers. It can be found at www.ewg.org/2010sunscreen/finding-the-best-sunscreens.
10. The Food and Drug Administration is working on new regulations for the sunscreen industry that should go into effect in 2012.