How can I tell if my sunscreen has expired?

Trust your nose and eyes, and keep a mental three-year timer. If the lotion is separated, watery, curdled, or has oil floating on top, toss it. A rancid, chemically, or off smell means the preservatives have failed. Gritty or chunky texture also means it’s done. Expired sunscreen won’t protect you, and a sunburn is worse than buying a new bottle.