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

The expiration date of a hand sanitizer probably has much in common with an expiration date of a bottled water. In the second case, printed date shows the tested durability of the plastic bottle, after which it slowly begins to decompose and let microplastic go to the water, then to your stomach.

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Or it could be that alcohol just evaporates (no container is hermetic enough, unless its vacuum sealed) and after expiration date, it could just be not as effective (for example, the alcohol content would be less than 60%)