Water quality does not expire, but the reason for the expiry stamp is because of a 1987 New Jersey state law. The law requires all food products to display an expiration date of two years or less from manufactory date.
Although, there has never been any regulation by the U.S. Food and Drug Administration that outlines the actual shelf life of sealed water bottles. New Jersey then amended the law, but the expiry date stayed intact as it has become an industry norm.
The truth of the matter is that unopened bottled water is neither good or bad for you.
Aged water bottles are relatively safe but the plastic packaging of the bottle, which contains polyethylene terephthalate (PET) can leak into the water and ruin the taste.
So it’s safe to say to opt for a fresh bottle after the two-year expiry mark.