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 thought it had to do with the plastic bottles. Bottled water has a shelf life of 2 years. Not the water itself but the plastic bottle. Plastic starts to degrade and contaminates the contents of the container. I thought this was the same reason anything in a plastic bottle has an expiration date.