Why do Plastic Water Bottles Get Smelly?

You may have noticed that disposable plastic water bottles tend to get smelly after a while, usually a week or two after they’ve been opened. The icky smell kind of creeps up on you and gets worse and worse as time goes on. That can pose a dilemma for people who like to refill and re-use water bottles in order to save money and limit their waste.

But why do these water bottles start to smell foul so quickly? Other types of water bottles that are made out of different material like stainless steel or aluminum don’t seem to have this problem. And not all plastic bottles even have this problem, why is that?

The disposable plastic bottles are made out of really cheap plastic that is more sensitive to heat and light than higher-quality plastic containers. If they are left in the sun or heat they can degrade quickly, causing unwanted odor.

Although that can be a factor, the biggest culprit causing the smell is bacteria that builds up on the inside of the plastic bottle. We all know that any moist surface is a magnet for bacteria, and the inside of a water bottle is by definition wet. Even if the bottle is empty, the inside of the plastic is probably lined with condensation caused by evaporated water that was left in the bottom of the bottle.

Once bacteria and stains begin to build up on a plastic surface it can be difficult to get rid of them. This is especially true with the water bottles that have such a small mouth, making it almost impossible to get any kind of cleaning utensil inside of it. Most people simply throw away the water bottle when it begins to smell and replace it with a new one.

If you are intent on getting rid of the smell and reusing your water bottle for a longer period of time, there are a few things you can do to try and eradicate the odor. Obviously, these bottles can be put in the dishwasher so you’re going to have to try to do your best to clean by hand.

Fill the bottle three quarters of the way full with water and then put soap or detergent in it. Shake the bottle violently for a minute or so and then fill it up with water to the top. Let the solution sit inside the bottle for up to 24 hours in order to loosen up any dirt, grime, and bacteria that have built up. Afterwards, thoroughly rinse it out with fresh water.

That will usually freshen up the smell and let you reuse it for a while longer until it inevitably comes back again. If this seems like too much trouble to go to, it would be in your best interest to invest in a higher-quality water bottle that is designed to be reused and cleaned over and over again.

That really is very much better long-term solution than trying to reuse disposable plastic water bottles. If the toxic chemicals leaching from the plastic don’t get you, the icky smell will. It’s better to spend a few dollars and get a true solution.

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