Whether it’s walking down a dark street at night or fighting off grizzly bears on the trail, pepper spray is an effective tool to fend off an attacker and get safely away. But have you ever thought about what gives this personal-defense-in-a-can its bite – is it just weaponized hot sauce? The American Chemical Society takes a look at what’s in these little canisters and why it inflicts so much pain. And for those times when you accidentally spray yourself, there are some tips on what to do.