What’s that stuff? Sunscreen

Abstract

Everybody needs sunscreen, including people with dark skin. And we need a lot. For the average-sized adult or child, the US Food and Drug Administration recommends using at least a shot glass–sized amount on your bathing suit–clad body every 2 h, even on cloudy days. In addition to blocking all the kinds of sunlight that can damage skin, sunscreen needs to be spreadable and not damage us. Different types of sunscreens achieve these goals in several ways. Here is a look at what the ingredients in a sunscreen tube do. Active ingredients: 10–30% Probably the most important parts of sunscreen are the compounds listed as active ingredients. These sun filters, or ultraviolet filters, protect our skin from the sun. Most sunscreens are a mixture of more than one UV filter, says Nada Baalbaki, senior manager of global scientific communication and clinical research at CeraVe, a skin-care company. Companies use a