Why does bottled water have an expiration date

Question

ok so i thought maybe purified water should have an expiration date becouse maybe it has something in it that expires, but for sur i know spring water shoudnt expire right? Water is like a billion years old already why would it have an expiration date on the bottle then? I think were all being scammed what do you think?

Answer 1

water might get stale.

=]

Answer 2

Im not sure exactly but it is known that you are not supposed to refill plastic water bottles now. because most water companies use more economically safe plastic, once you start refilling something from the plastic seeps into your water and apparently can make you very sick. It might be because after a while the plastic chemical can start to seep in.  

Answer 3

Your everyday bottled water is not PURIFIED water. It's usually filtered to take out impurities, but still isn't pure water. Impurities will affect the taste after a while. Also, chemicals in the bottle can leach into the water, affecting the taste. Try drinking bottled water that's about a year old and you can tell the difference.  

Answer 4

it's the bottle that expires, not the water.duh. no one's scamming you out of bottled water.chill.

Answer 5

There is a minute level of bacteria in practically everything on earth.  My understanding of expiration dates on bottled water is that in ideal conditions for growing bacteria (say you left that bottle of water on a warm sunny window ledge for a year - unlikely, I know, but for the sake of argument) the bacteria levels in the water would rise enough to potentially make you sick.  

I could be wrong, but I remember having this discussion with my high school science teacher at some point.  That mostly-remembered conversation is my only source material though.