All companies that produce consumables must, by federal law, have an expiration date on it. Since bottled water is a consumable the company must put a expiration date on it.
Also some water becomes impure due to plastic melting or substances released into the water by the plastic.
Here are opinions and answers from WikiAnswerers:
Please do not make the mistake of thinking that "Bottled Water" means pure, sterile, perfect water. It may surprise you to know that there is very little regulation concerning 'bottled water'. For example, it is common practice to label the bottle with such things as " Spring Water" or "Mountain fresh" while the water is actually taken directly from municipal sources! Look for yourself at the fine print and see.
The information above is accurate and well written. Irradiation is, however, not all that expensive, as all that is required is to expose the water to a radioactive source. It is very passive. The problem is that consumers are less than excited about drinking "irradiated" water. The second problem is planned obsolescence. Water with a shelf life must be replaced whether it is consumed or not, which increases sales.
Bottled water is, for the most part, an ecological disaster. The plastic is not fully recycled--much of it ends up in land fills, or burned in waste to energy plants. Also, municipal water supplies are just as safe, and frequently safer, than bottled water--which often comes from municipal water supplies--as noted above.
Here are additions to the answer:
It is just giving warning that it will taste different from what it did when bottled.
They're is an expiration on water bottles because most of the time companies will put fluoride in water and the fluoride expires so they need an expiration date
Bottled water is pointless, If you had to choose between water that had chemicals put into it or natural pure water, the natural water is better because it has fluorine in it and most of the bottled water won't have fluorine. Plus, how can water expire within a protected container? Because plastic would take a long time to decompose and water wouldn't expire in it.
Water kept in a plastic container is harmful because bottles are made up of toxic substances which are harmful for both animal and plant life.In nature, as per its property water flows which keeps it clean and pure, not allowing any source of crude deposition. But water if kept enclosed for a prolong period allows anaerobic algae and other microbes to grow in it;making it unsafe and unfit for potable use. Hence, pouched water possesses an expiration date on it. The plastic chemicals will get to it. The water can go stale, too.
It would probably still be potable, but bottled water does have an expiration date stamped on it.
Bottled water cannot go out of date.
Though water itself doesn't expire, bottled water often has an expiration date. ... This is because plastic can begin to leach into the water over time, contaminating it with chemicals, such as antimony and bisphenol A (BPA) ( 5 , 6 , 7 ).
Most beers have either a drink by date, or a bottled date. In general, beer will last up to 4 months from the bottled date so it will be easy to calculate its expiration date.
Bottled water does not spoil, however it comes with an expiration date because it can eventually absorb the taste of the plastics that contains it. The plastic-infused water is not harmful, but it may not taste good.
For the most part, water has an indefinite shelf life. Bottled water sometimes has an expiration date, but this doesn't mean that the water has gone bad if you drink it past that date. However, if you open the bottle and the water smells strange, then you should dispose of it.
Most soda bottles will have an expiration date on them. As long as they are not stored in extreme heat or cold, they should be fine at least until the expiration date, if not, longer.
If it smell ok and the taste hasn't gone of it should be fine.
if it has no air in it up to a year and if it hasn't been opened. but if it has then about 2 weeks maybe? But i say if its past a month then don't drink it
Coconut water can expire and the expiration date is shown on the package. When the water has past the expiration date, it's best to discard.