This is a much-argued point, and there is not enough science out there to back any extreme position. There seems to be increasing evidence that oxybenzone, a very common chemical sunscreen, may act like estrogen in the body, which increases the likelihood that it will disrupt our innate hormone cycles. Another controversial chemical is retinyl palmitate, which can slow skin aging but may actually accelerate the development of certain skin cancers when it comes in contact with ultraviolet light. PABA is not used as much as it once was, but there’s a fairly large population of people who are allergic to that ingredient by now. In short, there are several really good arguments for using a non-nano physical sunscreen made with zinc oxide or titanium dioxide: They are not absorbed by the skin; they are not degraded by exposure to sunlight, making them more stable over time; and there are often fewer and less toxic ingredients that make up the "inactive" ingredients in the product. To sum it all up—what should you look for in a sunscreen?
Look for fewer ingredients overall, stick with non-nano zinc and titanium particles until we know more about the effects of nanoparticles, and look for a product with no parabens and no fragrance. (Even essential oils oxidize in sunlight, which can increase your chance of having a skin reaction to them.) An SPF of 30 is probably sufficient, and you should still be wearing hats and long sleeves whenever you’re not splashing in the water. Here are some of the natural sunscreens that made it to the EWG's list of approval this year. To check out the rest, head here.
Here are some more natural, non-toxic sunscreens we're loving right now.