At least the Environmental Working Group (EWG), which offers a guide to sunscreens, identifies the chemical filters in broad spectrum sunscreens by name. Most, it maintains, combine two of the following six following active ingredients: oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate. We know next to nothing about how these interact with the human body, especially that of a human child. EWG does single out one, oxybenzone, "added to nearly 65 percent of the non-mineral sunscreens in EWG's 2017 sunscreen database," as potentially pretty dangerous. EWG cites a recent evaluation of CDC-collected exposure data for American children, in which researchers found that adolescent boys with higher oxybenzone measurements had significantly lower total testosterone levels.