Published: August 25, 2017

    Why Does My Bottled Water Expire?

    Water is the purest source of nourishment on the planet. You just need two parts hydrogen, one part oxygen, and a container to keep it in. Many families are surprised, then, to learn that bottled water actually has an expiration date.

    What happens if you ignore the “sell by” date on bottled water? How is it possible that water could degrade in quality? When preparing for a disaster we’re told that we should switch out our stored supply of water every six months – why is that?

    It’s common knowledge that if you leave a bottle of water exposed in a hot car you shouldn’t drink it. BPA and other chemicals from the bottle can leach into the water itself, a process that is sped up by the heat of the sun.

    The reason why bottled water, even in large industrial jugs, has an expiration date is the same. It isn’t the water itself that you must worry about – it’s the plastic that surrounds it. Retail bottles of water are typically packaged in a plastic called polyethylene terephthalate (PET). Those larger water storage jugs you may have tucked away in your basement are likely to be constructed with high-density polyethylene (HDPE).

    Eventually, this plastic will begin leaching into the clean water you’ve stored. This process creates multiple issues with your drinking water:

    • The taste of your water transforms from the smooth, simple taste of clean water to a more metallic, bitter taste.
    • Due to the porous nature of the plastic smells from outside the water container can become trapped in the bottled water, causing an unpleasant drinking experience.
    • Most importantly, as the plastic continues to leach into the bottled water you become more at risk for serious health problems as the water becomes more toxic.

    However, you should not necessarily throw away water the moment it expires. Some water is perfectly fine to drink months and months after the printed expiration date. So why are the dates seemingly arbitrary?

    The reason every bottle of water has an expiration date is due to a law passed 30 years ago in the state of New Jersey. This law stated that all food products must display an expiration date clearly on the packaging. For efficiency’s sake most manufacturers started including 2-year expiration dates regardless of the packaging type they used.

    So, are in danger if you drink water that “expired” a year ago? Most likely not. The probability of plastic leaching does increase the longer the water is stored, so use your best judgment and when in doubt take the cautious route. After all, the law in New Jersey has since been changed, but the expiration dates on bottled water remain.

    Eliminate the mystery entirely by not drinking from plastic bottles at all! Installing a water filter at home and drinking pure filtered water guarantees a clean, refreshing glass of water every time you turn on your tap. If you need to drink water on the go, fill a stainless steel bottle with filtered water and take it with you to work or to class.