Shelf Life of Bottled Water – Does Bottled Water Go Bad?

Shelf Life of Bottled Water - Does Bottled Water Go Bad?

We’ve all done it: lost a bottle of water in the back of our pantry only to miraculously find it one day while spring cleaning, but if you’re unsure how long it’s been back there, how do you know if it’s safe to drink? Can bottled water even go bad?

As a general rule, unopened water doesn’t go bad; however, the plastic bottle can break down over time, leaking chemicals into your water. As a rule of thumb, bottled water is safe to consume within two years of purchase. For sparkling water, this is reduced to one year.

A rule of thumb is great, but what if you don’t know when the water was purchased? Keep reading to learn the signs that your bottled water may have turned bad.

Check out my article about whether bottled water is bad for you.

What Causes Bottled Water to Go Bad?

Water, itself, doesn’t go bad. This is because water is only made up of two hydrogen atoms and one oxygen atom, giving us the familiar H2O, or dihydrogen monoxide, name. There is no sugar, artificial flavorings, or other added ingredients that can spoil within the water.

For opened bottles of water, when people say water has “gone bad,” they typically mean bacteria have gotten inside the water. Usually, this bacteria enters the water from your mouth as you drink it, but it can also enter from contact with the air. This accumulation of bacteria can be dangerous to drink, depending on the type of bacteria and on a person’s overall health at the time of consumption. This bacteria will give your water a foul or off smell to it, which is a sign it may be time to throw it away.

For unopened bottles of water, the reason it goes bad is due to the breakdown of the plastic bottle. Plastic bottles have a shelf life of about two years, so the water inside them also has a shelf life of two years. After these two years, microscopic bits of plastic can leak into the water and can be dangerous to drink, leading to health complications for some people. This is especially true in hot climates, as the heat allows plastic particles to move more freely, increasing the chances of the particles leaking into your water.

How Long Does Bottled Water Last?

Bottled water lasts different amounts of time depending on if it’s normal drinking water or sparkling water if it is refrigerated or not, and if it is opened or closed. The following table lists how long an opened and unopened bottle of water lasts at various temperatures.

TemperatureOpened Bottled WaterUnopened Bottled Water
Normal Water (Room Temp.)Not Recommended2 years
Normal Water (Fridge)3-5 days2 years
Sparkling Water (Room Temp.)Not Recommended3 months
Sparkling Water (Fridge)2-3 days3 months

Refrigeration doesn’t extend the shelf life of unopened water very much, as the plastic bottle will still eventually begin to break down, despite the cold temperature of the water.

The Signs Your Water Has Gone Bad

A rule of thumb is great, but what if you don’t know when you purchased your bottled water? How do you know if it’s safe to drink?

While the circumstances surrounding every bottle of water may be different, depending on the climate of the room the bottled water is stored in and the type of bottle, it is stored in; there are signs you can look for the know if your bottled water has gone bad.

If you’re unsure if your bottled water is safe to drink, before opening it, look at its color. Your water should be crystal clear. If there appears to be anything floating in your water, or its color seems a little off or cloudy, discard the water and do not drink it.

If there doesn’t appear to be anything wrong with your water’s color, next open it and smell it. Bottled water should smell like nothing. If the smell is slightly off or foul, discard the water and do not drink it.

If your bottled water passes the smell test, another step you can take is to take a very small sip of the water and swish it around your mouth. If your water tastes at all bitter, slightly off, or foul, discard the water and do not continue to drink it.

If you are at any time unsure of the quality of your water, do not drink it. It is better to err on the side of caution and be safe than to risk drinking potentially contaminated water.

Ways to Extend Your Bottled Water’s Lifespan

Unfortunately, signs your bottled water has expired are not always immediately noticeable, but there are steps you can take to prolong your water’s lifespan.

A good way to keep your water healthy to drink longer is to simply not open it until you are ready to drink it. Opened water bottles allow bacteria to enter, possibly contaminating your water. The longer the water sits after opening, the more bacteria will enter and multiply in your water. Keep the bottle closed until you are ready to drink it, and always close your bottle’s lid tightly.

One way you can extend the quality of your bottled water is to choose your products wisely. While some bottled water is not BPA-free, there are BPA-free products on the market you can choose from. BPA stands for Bisphenol A, an organic compound used in the creation of some plastic bottles. When the plastic bottle begins to break down, bottles with BPA will release the BPA into the water as well. While most people ingest very little of the chemical, despite its uses in many products, it can be dangerous when ingested. Making sure your water bottles are BPA-free increases the likelihood that they will be safe to consume for a longer period of time than their BPA-containing counterparts.

Another way to ensure your water stays healthy to drink for a longer period of time is to keep it in a climate-controlled room. Rooms such as kitchens are typically set to a comfortable living temperature and are great for storing bottled water. Garages, on the other hand, are typically not climate controlled and can be much hotter than the rest of the house, depending on where you live and the time of year. It is a good idea to avoid storing bottled water in the garage when temperatures are high outside.


Bottled water can be tricky to know when it’s gone bad sometimes. We don’t always keep in mind the date we purchased things. However, by storing and thoroughly checking your bottled water using these suggestions and your own instincts, you decrease the likelihood of drinking contaminated water.

Boch Richard

Richard Boch is a chemical engineer responsible for designing water filtration systems for industrial and residential customers. He has more than 20 years of experience with ion exchange, activated carbon, and reverse osmosis. Richard's expertise has made him a go-to source for municipalities and businesses looking to improve their water quality. When he's not working, Richard enjoys spending time with his wife and two young children.

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