At this point you might be thinking that the best solution is to just buy only non-organic, mineral-based sunscreens. Maybe, but these aren't perfect, either. Although most mineral sunscreens don't absorb UV light — the molecules sit on top of the skin and reflect or scatter the rays _they leave a white, greasy film on the skin that many people find annoying. Yes, annoying sounds preferable to damaging, but the only way sunscreen works is if your kids apply it. The less thick and greasy, the better. Newer "nano" formulations of these mineral sunscreens are much more pleasant, but they don't reflect UV light as effectively — and they also absorb UV light in addition to reflecting it, which means they too can produce reactive oxygen species.
As for SPF, most dermatologists and the Environmental Working Group now recommend avoiding anything above 50 because they give us a false sense of security, so we stay out longer while forgoing necessary reapplication. The numbers are deceiving anyway: SPF 50 protects against 98 percent of the UVB rays, but SPF 30 protects against 97 percent of them — not exactly a critical difference.
And what about application method-sprays, gels, wipes, or old-fashioned lotions? The Environmental Working Group warns against sprays because of the risk that the chemicals could be inhaled or get into the eyes. But if your child won't let you near her with anything but a cool mist, by all means use it-just ask him to hold his breath and close his eyes as you apply it. The EWG also warns against combination sunscreen/bug sprays, which may increase absorption of the repellant chemicals, and sunscreen wipes, which might not deliver adequate protection.
As for all the other sunscreen chemicals you might see listed on the back of your bottle: They have been FDA-approved, so they have been tested for safety to a certain degree, but few academic scientists have independently assessed their potential health effects because it's difficult to get funded for such studies.