What it is: Silicon dioxide is what gets in your bathing suit and your hair at the beach. Affectionately known as sand, it’s also found in food. “It’s used in a lot of things as a flow agent and partly because it does a nice job of absorbing a little bit of atmospheric humidity that would cause clumping in a variety of things,” says Milkowski.
Swallowing a little sand at the shore probably never hurt you and it probably won’t hurt you at the dinner table either.
Where you’ll find it: Salts, soups, and coffee creamer.