View full lesson: http://ed.ted.com/lessons/which-sunscreen-should-you-choose-mary-poffenroth

Sunscreen comes in many forms, each with its own impacts on your body and the environment. With so many options, how do you choose which sunscreen is best for you? To answer that question, Mary Poffenroth explains how sunscreens work and compares different application methods, SPFs, and active ingredients to help you make the best choice.

Lesson by Mary Poffenroth, animation by Rob Kohr and Travis Spangler.