Eli5: How come hand sanitizer has an expiration date? What exactly happens once it goes past it?

Question

Eli5: How come hand sanitizer has an expiration date? What exactly happens once it goes past it?

In: Chemistry

Answer 1

I invented Germ-X so I can weigh in here. It is an OTC drug and it is required to have an expiration date per the FDA to which it must by registered by law. When I developed it it went through three months of stability testing which gave it a shelf life of two years. Anything beyond that the product loses efficacy as the alcohol will very slowly evaporate. Some of these comments are pretty accurate and a couple are pretty amusing.