Sunscreens need to be replaced every year. The active ingredients break down, especially when exposed to heat (like in your car or a beach bag). Not only will old sunscreen give you less protection, but you might get a reaction to it if you have sensitive skin. — King

There are three ways to tell if your sunscreen has gone bad: 1. Weird consistency, it’s too thick or too thin. 2. Crystallization, it feels gritty. 3. Separation, it looks like it’s in two layers. In all cases you’ll want to buy a new bottle. — from the book, “Can You Get Hooked on Lip Balm?”