How long can water sit in a water bottle?

Water sitting in a water bottle for an extended period of time can become unsafe to drink. How long water can safely remain in a bottle depends on several factors, including the material of the bottle, temperature, exposure to sunlight, and potential bacterial growth. Understanding these factors can help determine if old bottled water is still potable.

Quick Answers

– Unopened commercially bottled water can be safely stored for 1-2 years past the stamped expiration date if kept in a cool, dark place.

– Opened bottled water or tap water stored in a reusable bottle should not be kept for more than a few days.

– Plastic bottles leach chemicals into water over time and should not be used for long-term storage.

– Glass or stainless steel bottles are best for storing water for more than a couple days.

– Keeping water bottles refrigerated and away from heat and sunlight extends safe storage time.

– Look for changes in taste, smell, or appearance as signs that stored bottled water may no longer be safe to drink.

How Long Can an Unopened Bottled Water be Stored?

Commercially packaged bottled waters such as those you would purchase in a grocery store or convenience store are meant to be shelf-stable. Sealed, unopened bottled waters can maintain safety and quality for quite some time past the stamped expiration or “best by” date.

According to FDA guidelines, commercially bottled water in a sealed container can be safely stored for 1-2 years past the expiration date printed on the bottle. After this time, degradation of the plastic bottle and chemical leaching may cause off-tastes or odors in the water. However, the water remains potable and safe to drink for up to 5 years past the printed date.

To get the maximum safe shelf life from bottled water:

  • Store unopened bottles in a cool, dry place away from heat and sunlight. The ideal storage temperature is 40-70°F.
  • Avoid storing bottles in hot places like garages or near stoves.
  • Keep them out of direct sunlight, which can promote algae growth and plastic degradation.
  • Store bottles upright and make sure seals are intact before consuming.

Does Bottled Water Expire?

The expiration date on a bottled water refers to the date up until which the manufacturer guarantees ideal taste, quality, and nutritional value. After this date, plastic degradation and chemical leaching may affect taste but do not necessarily make the water unsafe.

If stored properly in a cool, dark place, unopened commercially bottled water can be safely consumed up to 1-2 years past the printed expiration date. After that, taste may start to suffer but the water remains potable up to 5 years past the date.

So while bottled water does technically “expire,” it remains safe to drink for quite some time after the printed date, as long as containers remain properly sealed.

How Long Does Water Last in a Reusable Bottle?

For reusable drink containers like plastic, stainless steel, or glass water bottles, storage times are much more limited than commercially bottled water. Tap water or other non-sterile water added to reusable bottles should not be stored for more than a few days.

Once introduced into a reusable drink container, bacteria and protozoa from the municipal water supply, the bottle material itself, or your mouth can multiply rapidly if left untreated. The CDC warns against drinking water that has been stored for longer than 24 hours in reusable bottles.

To safely store water in reusable containers:

  • Always wash and fully air-dry bottles after each use.
  • Do not let bottles sit with residual moisture inside, which promotes bacterial growth.
  • Use good quality drinking water, ideally filtered.
  • Avoid touching mouthpieces to prevent bacterial contamination.
  • Refrigerate bottles while not in use to slow bacteria multiplication.
  • Consume water within 24 hours of filling bottle, and refill with fresh water often.

With vigilant cleaning and refrigeration, opened reusable water bottles should be emptied, washed, and refilled every 1-2 days for safest quality.

How Long Does Water Last in a Plastic Bottle?

Plastic water bottles, whether commercially bottled or reusable, come with concerns around bacteria as well as risks from chemical leaching.

BPA and phthalates found in some plastic bottles can leach into the water, especially if exposed to heat or sunlight. After 6 months, chemical leaching may impact taste and quality. For this reason, plastic is not ideal for long term water storage.

If using plastic bottles, limit storage times to no more than 2-3 days for reusable bottles, and 1-2 years for unopened commercial bottles. Never reuse disposable plastic water bottles.

How Long Does Water Last in a Glass Bottle?

Glass provides an inert container for safe water storage. It does not leach chemicals into the water over time. Unlined aluminum can leach aluminum and is not recommended.

As with any bottled water, bacteria growth is still a concern. Properly wash and air-dry glass bottles after each use and limit storage time to 24-48 hours for reusable glass bottles.

Commercially bottled glass water containers should be discarded after 1-2 years past the printed expiration for best taste.

How Long Does Water Last in a Stainless Steel Bottle?

Stainless steel water bottles provide another good option for reusable bottled water storage. Stainless steel does not leach chemicals into water over time.

Care should still be taken to wash and fully dry bottles after each use to prevent bacterial growth. Refrigerate stainless steel bottles when not in use and limit reusable bottle storage time to 24-48 hours for best safety and taste.

What Affects How Long Water Stays Fresh in Bottles?

Several external factors impact how long bottled water retains freshness and safety, including:


Heat accelerates plastic degradation in bottles and provides optimal conditions for bacteria growth. Store bottles in cool, shaded areas or the refrigerator.

Sunlight Exposure

UV rays from sunlight can break down plastic materials in bottles, causing chemical leaching. Keep bottled water in dark storage.

Opening/Resealing Bottles

Once opened, bottled water should be consumed within 24-48 hours. Anytime a seal is broken, potential for contamination exists.

bottle Material

Plastic bottles have shorter shelf lives than glass or stainless steel. Use glass or stainless steel for storing water more than 2-3 days.

Source of Water

High-quality drinking water with proper filtration will stay fresher tasting than unfiltered tap water.

How Can You Tell if Old Bottled Water is Bad?

Look for the following signs that stored bottled water may no longer be pleasant or safe to drink:

  • Appearance: Cloudiness, particles, algae growth inside bottle
  • Odor: Smells stale, musty, rotten
  • Taste: Metallic, chemical, soapy, bitter
  • Color: Darkening or discoloration

If water exhibits a change in odor, taste, or appearance, err on the side of caution and discard it. With reusable bottles, cleaning and refilling with fresh water is recommended.

Can You Get Sick from Old Bottled Water?

Drinking spoiled bottled water can potentially make you sick. Bacteria like pseudomonas, escherichia coli, and klebsiella multiply over time in stored water and can lead to nausea, vomiting, diarrhea, and other symptoms if ingested.

Chemical leaching from plastic bottles can also cause health issues with long term consumption.

If in doubt, don’t drink bottled water that is past its prime. Safety can’t be guaranteed on water stored over recommended times, especially if seals are broken or other signs of spoilage observed.

Frequently Asked Questions

Can you drink water left in a hot car?

No, you should avoid drinking bottled water left in a hot car. The heat causes plastic to break down faster, releasing chemicals into the water. Bacteria also grow rapidly at high temperatures.

Does cold water last longer in bottles?

Yes, refrigerating bottled water helps slow bacteria growth and extend the drinkable window to 2-3 days from 24 hours for reusable bottles. It also inhibits plastic degradation.

Should you rinse reusable water bottles between refills?

Yes, always wash reusable bottles with soap and hot water between refills, even if just filling with water. Allow to fully dry before adding fresh water to limit bacterial growth.

Can you get sick from drinking old water?

Yes, bacteria and toxins can build up in bottled water stored past recommended times. Old water may cause nausea, diarrhea, vomiting if consumed after becoming contaminated.

Do water bottles go bad if sealed?

Sealed, commercially bottled water remains fresh 1-2 years past its expiration date if properly stored. After this, plastic leaching can occur over time, but water remains potable if sealed.


Fresh, clean drinking water is essential for health. With the right bottles and storage methods, keeping bottled water safe and pleasant for a reasonable time is possible. Glass or stainless steel reusable bottles, cleaned properly after each use, provide the best vessel for storing water up to 24-48 hours. Commercially bottled waters in plastic bottles remain drinkable 1-2 years after the printed expiration when kept in cool, dark conditions. If water exhibits odd smells, tastes, or a change in appearance however, it is safest to discard potentially contaminated bottles and start fresh.

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