You’re getting ready for work and about to get dressed when you realize you’ve run out of deodorant. Now, it’s time to panic. Except maybe not. There’s a common first aid item that could help get you by until you’re able to get to the store.

You can use rubbing alcohol as a deodorant, or at least use it to kill the bacteria that cause odor.

To understand how this works, you need to know how body odor actually happens. Essentially, it’s all due to sweat and bacteria. When you sweat, it comes into contact with the bacteria that live on your skin. Sweat itself doesn’t smell, but when the salt, fat, water, and bacteria all mix, that’s when body odor starts. Part of eliminating body odor is eliminating the bacteria that cause it. That’s where alcohol comes in.

Isopropyl alcohol—or rubbing alcohol—that at least 70% can kill bacteria by denaturing their proteins and dissolving their lipids. When there aren’t any bacteria for your sweat to mix with, body odor won’t be as much of a problem.

To use his hack, you won’t want to go above 70% rubbing alcohol. If you do, it could lead to irritation. Once you’ve got your alcohol, make sure your armpit is dry, and then spray or rub a bit under your arms. Let it dry, and you’re on your way. Of course, there is one warning—if you shave, don’t apply the alcohol immediately after unless you want some serious burning.

If you’re ever in a panic over running out of deodorant, just reach for your first aid kit.