What happens on that fateful date? Does it disappear? Does it suddenly become toxic? How does the purity of clean water sealed in a container suddenly become compromised?

Everybody has that moment when they realize they don’t know about something that they should probably know about. Whether it’s history, language, science, or cultural phenomena, you’ve felt the stinging personal embarrassment of a moment wherein you realize there’s some common knowledge that isn’t so common. Don’t feel bad; nobody knows everything. Nobody, that is, except me and my sidekick, The Internet!

Somewhere in the world, a confused soul begs the question…

Why Does Bottled Water Have an Expiration Date?

We’ve all wondered what would happen when water “expired”. Does it disappear? Does it suddenly become toxic? How does the purity of clean water sealed in a plastic container become compromised on a certain date?

Spoiler alert: water does not expire (the Food and Drug Administration maintains that bottled water has an indefinite shelf life). Water’s expiration date exists for another reason.

In 1987, New Jersey instituted a law that required all food and beverage products sold in the state to, at the time of manufacturing, be marked with an expiration date of two years (or less). Because water obviously qualifies as a beverage and H2O always plays by the rules, all bottled water sold in New Jersey would require an expiration date. Bottled water manufacturers didn’t see a whole lot of sense in producing some bottles with expiration dates (exclusively for New Jersey) and some without (for everyone else) so, every bottle everywhere started to get an expiration date of some kind.

New Jersey’s regulations (and other similar state laws) have since changed and so, there is currently no authority mandating that water must carry an expiration date of any kind (bottled water manufacturers continue the practice, mainly out of habit). However, over time, water can absorb tastes and smells through the slightly porous plastic containers in which it resides so… though the product may not go stale, the longer you leave that case of Dasani in the trunk, the greater the chances it will smell a bit funky when you finally break the seal on the cap.

Now you know.