How does sunscreen protect your skin?
Sunscreen ingredients prevent UV rays from damaging your skin. There are two categories of sunscreen ingredients, George says.
Physical blockers
Physical blockers contain minerals such as titanium dioxide or zinc oxide ground into fine particles. These minerals sit on the surface of the skin and reflect UV rays away from your skin “a lot like a shield or mirror would,” George says. Sunscreen products that physical blockers are sometimes called sunblock or mineral sunscreens.
Chemical absorbers
Chemical sunscreen ingredients form a thin protective film that absorbs UV radiation before it penetrates the skin. Sunscreen products that contain chemical absorbers are sometimes called organic sunscreens.
Both types of sunscreen ingredients have pros and cons.
For example, physical blocker sunscreens generally do not cause irritation, stinging or allergic reactions, but they can be white and greasy. Meanwhile, chemical absorber sunscreen ingredients are usually clear and easy to apply, but these are more likely to cause irritation and allergic reactions.