Why do common household items (shampoo, toothpaste, medicine, etc.) have expiration dates and what happens once the expiration date passes?

Question

Why do common household items (shampoo, toothpaste, medicine, etc.) have expiration dates and what happens once the expiration date passes?

In: Other

Answer 1

Medicine is usually because it loses effectiveness as it gets older. Shampoo and toothpaste etc is usually expiration date for the packaging rather than the product – the manufacturer didn’t verify that the plastic bottle (or whatever) is tight after that date.