Why Do Bottles of Water Have Expiration Dates?

It is common knowledge that water does not expire. It may taste funny after a while of sitting out, but it is generally still good to drink. So, if this is the case, why do bottles of water have expiration dates?

It has nothing to do with the water, and all to do with the plastic bottle. According to Healthline, bottles of water have expiration dates because over time, "plastic can begin to leach into the water over time, contaminating it with chemicals, such as antimony and bisphenol A (BPA)...If ingested regularly, these plastic compounds can slowly accumulate in your body, which could harm gut health, immunity, and respiratory function."

While you will not keel over if you drink an expired bottle of water, don't make it a habit.