Bottled water that hasn't been stored properly can contain contaminants you're better off avoiding.

Image Credit: mikroman6/Moment/GettyImages

In This Article

    Types of Water
  
    Bottled Water Expiration
  
    Tap Water Expiration
  
    Storing Water Safely
  We've all heard of the dangers of leaving a bottle of water in a heated car for too long. Is there any truth to that sentiment?

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 There are many situations where you may need to store water for an extended period of time. Situations like packing for disaster relief or stockpiling water for the future both require you to know how to store your water safely (more on that below).

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  Below, a closer look at whether different types of water expire.

Types of Water Tap Water The Environment Protection Agency (EPA) is responsible for the clean drinking water that we get from the tap. In fact, these EPA-regulated public drinking water systems provide safe drinking water to 90 percent of people in the U.S.

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 Bottled Water

There are four different types of bottled water, according to the FDA:

‌Mineral water:‌ Water that comes from an underground source and contains natural minerals and trace elements. ‌Spring water:‌ Water that comes from an underground formation and is collected at the spring or through a shaft in the ground. ‌Well water:‌ Water that comes from a hole in the ground, which taps into an aquifer (earth that holds groundwater). ‌Artesian well water:‌ Water that’s collected from a well that taps an aquifer. The pressure in the aquifer (also called artesian pressure) pushes the water above the level of the aquifer, sometimes to the surface.

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 Rainwater

While the CDC advises against drinking rainwater without treating it because it can contain germs and other contaminants. However, you could use this collected water for other resources, including bathing and watering plants, to help conserve your water, per the CDC. Does Bottled Water Expire? This is a tricky one: Technically, the water itself doesn’t expire, but it may be in your best interest to skip drinking from an old bottle.

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 "Water in the sense of itself does not expire; however, the material water is packaged in can break down and leak contaminants into the water itself," says dietitian Andrew Akhaphong, RD.

And dietitian Abigail Thomas, RD, agrees: “Water does not expire, but it is through the elements that surround the actual water itself that changes the chemicals in the water,” she says. “It is not the water that expires but the container itself that holds the water that experiences degradation that ultimately has an impact on the water.”

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 PET

Bottled water is sold in polyethylene terephthalate (PET), which is denoted by a #1 on the bottom of the bottle, per Clean Water Action. Research suggests that PET might act as an endocrine disruptor, however, more human studies need to confirm these findings. While phthalates and other chemicals can leach into water from PET bottles — especially when exposed to high temperatures or stored for an extended period of time — a November 2021 study in ‌Natural Science in Archaeology‌ found that their concentration was not high enough to pose a threat to people.

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 What's more, water bottle plastic is a bit permeable, which may allow air gases to leech in and change the taste and smell of your water, according to the International Bottled Water Association.

BPA Another thing to consider is taking in microplastics and their chemicals over time.

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 "An example is the use of bisphenol A (BPA) in the manufacturing of polycarbonate plastics," says Akhaphong. "BPA contamination in bottled water includes heating of the material or constant scratching and being rough with the bottle. BPAs are considered an endocrine-disrupting hormone."

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 An August 2022 study in ‌Ecotoxicology and Environmental Safety‌ looked at blood BPA levels among 1,093 people and observed that folks with higher levels of BPA in their bloodstream also had changes in lipid markers including increases in triglycerides and LDL (bad) cholesterol, a risk factor for heart disease.

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 "This is hypothesized to be because BPAs are likely to attach to estrogen receptors on the brown adipose tissue, a main regulator of fat metabolism, which becomes impaired and causes abnormalities in lipid markers," Akhaphong says.

Many manufacturers have removed BPA from their products for this reason. Tip Because bottled water doesn’t ‌technically‌ expire, the FDA does not require water brands to add an expiration date on their bottled water products. Still, many companies print an expiration date on their bottled water to ensure you’re getting the freshest H2O possible. Does Tap Water Expire? Unlike commercially bottled water that you buy at the store, tap water should be replaced every 6 months, per the U.S. Department of Homeland Security. “Tap water can be stored and for up to 6 months with minimal risk of adverse side effects as long as it has been stored properly,” says Moushumi Mukherjee, RD. How to Store Water Safely To store water safely, buy commercially bottled water and do not remove or unseal the original containers. You’ll want to store bottled water in a cool, dry place away from household chemicals if you’re planning to keep it for long-term storage, according to the U.S. Department of Homeland Security. That means you don’t want to leave bottled water in your car in the summer or in a hot basement or garage where the plastic containers could degrade faster.

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Bottled water that hasn't been stored properly can contain contaminants you're better off avoiding.

Image Credit: mikroman6/Moment/GettyImages

Image Credit: mikroman6/Moment/GettyImages

  • Types of Water
  • Bottled Water Expiration
  • Tap Water Expiration
  • Storing Water Safely

Because bottled water doesn’t ‌technically‌ expire, the FDA does not require water brands to add an expiration date on their bottled water products. Still, many companies print an expiration date on their bottled water to ensure you’re getting the freshest H2O possible.

            The 10 Best Reusable Water Bottles of 2023
           by
          Kelsey Kloss
          
            How Bad Is It Really to Reuse a Plastic Water Bottle?
           by
          Molly Triffin
          
            Are Your Plastic Water Bottles and Meal Prep Containers Safe to Use?
           by
          Bojana Galic