Commercially bottled water must have an expiration date. Often, that date is 2 years from the date it was bottled. Over time, plastic from water containers may begin to leach into the water and may affect health if consumed.

If you’ve ever purchased a pack of bottled water, you may have noticed an expiration date printed on the plastic packaging. Currently, most types of bottled water manufactured in the United States have an expiration date.

However, this can be a bit misleading and may cause you to wonder whether water is safe to drink after the expiration date has passed.

This article looks into whether water expires.

Tap water can be stored and consumed for up to 6 months with minimal risk of adverse side effects as long as it has been stored properly (1, 2, 3).

However, tap water that has been carbonated can become flat as the gas slowly escapes from the liquid, resulting in changes in flavor.

Regular water can also develop a stale taste over time, which is caused by carbon dioxide in the air mixing with the water and making it slightly more acidic.

Though these types of water may have an off taste, they’re still generally considered safe to drink for up to 6 months.

If preparing tap water for storage, use cleaned and sanitized food-grade water containers. Label them with the filling date and indicate that they contain drinking water. Store the containers in a cool, dry, and dark place for up to 6 months (4).

Summary

Tap water can be kept for up to 6 months. Though its flavor can change over time, it’s still considered safe to drink if properly stored.

Though water itself doesn’t expire, bottled water often has an expiration date.

In 1987, New Jersey became the first and only U.S. state to pass a law requiring that all food products — including bottled water — have an expiration date of 2 years or less from the date of manufacture.

When this law was passed, printing an expiration date became an industry standard for bottled water manufacturers across the country.

However, this law was later changed, and no current legislation in the United States requires manufacturers to print an expiration date on bottled water.

Still, it’s generally not a good idea to drink water from plastic bottles that’s way beyond its 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).

If ingested regularly, these plastic compounds can slowly accumulate in your body, which could harm gut health, immunity, and respiratory function (8, 9).

Additionally, bottled water that’s carbonated may eventually become flat, losing its carbonation and developing an off taste.

Summary

Though it’s not required, bottled water is usually printed with an expiration date. Over time, plastic can begin leaching into bottled water, which can negatively affect your health.

Storing bottled water properly can help prevent bacterial growth and reduce the risk of side effects, such as nausea, stomach pain, vomiting, and diarrhea (10).

In particular, warm temperatures can foster bacterial growth and increase the release of harmful plastic chemicals into the water (11, 12).

Keeping bottled water in a cool place out of direct sunlight can help promote proper food safety and reduce your risk of negative health effects.

Because plastic bottles are also slightly permeable, it’s best to store bottled water away from household cleaning supplies and chemicals.

If you notice that your water has developed an odd taste or odor, you should boil it before drinking or discard it.

Summary

Bottled water should be stored in a cool place out of direct sunlight and separate from household cleaning supplies and chemicals.

Tap water can be stored safely for up to 6 months.

Certain chemicals found in plastic can leach into bottled water over time, which could potentially damage your health. Thus, it’s probably best to avoid commercially bottled water that’s far past its expiration date.

Practicing proper storage techniques can help reduce the risk of side effects and ensure that your drinking water is safe.