Published: 17 March, 2005

Expiration on water bottles a question of law, good taste

Water doesn't spoil, but why do some water bottles have expiration dates?

There are several reasons for an expiration date on a bottle of drinking water. Some states require that every food item has an expiration date, so even candy or nuts and other perishables may have them. The other reason is the taste. As long as a bottle of water stays unopened, it is safe to drink. The taste however can change over the course of time. The plastic of the container can make the taste go bad when it is not stored properly. Also, sunlight can deteriorate the plastic and add to the bad flavor. Many gases are able to pass through plastics, which can affect the taste of bottled water. For those reasons, always store plastic bottles in a dry dark place without the presence of household chemicals (paint thinner, gasoline and dry cleaning chemicals). It is recommended that when a bottle of water is opened, it is used within two weeks, because algae or bacteria can start to grow and will cause health risks. So bottled water doesn't spoil when unopened, but the taste can change over time and some states require an expiration date. That's why bottled water has an expiration date.