# shelf life

Does a First Aid Kit Go Bad? What to Check, and When

Your kit doesn't have one expiration date — the stuff inside does. Here's what actually expires, what never does, and how to check everything in about 5 minutes, twice a year.

Does Hydrogen Peroxide Go Bad? Shelf Life & the 10-Second Fizz Test

That brown bottle in my medicine cabinet fizzed once, then quit. Here's what I've learned about hydrogen peroxide shelf life — the 10-second fizz test, why the brown bottle matters, and when it's time to toss it.