Is It Safe To Drink Unopened Bottled Water From a Car?

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You have a job where you work out of your car, and you have no place to safely store water between shifts. So you have the brilliant idea to store bottled water in your car, so you’d always have water. But after being in the car all summer long, would it still be safe to drink?

It is not safe to drink unopened bottled water from a car after it’s been sitting in the heat. The toxic chemical bisphenol A, or BPA, leeches into the water from the plastic bottles. BPA is thought to cause breast cancer and to be an endocrine disrupter. 

If you think that your bottled water is safe in your car during the summer, you may want to read this article. I will discuss why it isn’t safe and give you alternatives to plastic water bottles that are safer and more environmentally friendly. Let’s get started.

Unopened Water Bottles Left in Hot Car

According to some research, unopened water bottles left in a hot car can pose health risks due to potential chemical leaching and bacterial growth, so it is generally not recommended to drink them.

It’s best to store water bottles in cool, dark places away from direct sunlight, and if possible, consider using BPA-free, stainless steel, or glass bottles for added safety.

Let’s talk more about why hot bottled water is unsafe and why you should not store bottled water in the car.

BPA Leeches Into the Water

Bisphenol A, or BPA, is a chemical compound in most plastic containers, such as reusable plastic containers, water bottles, and other containers. This substance can leech into the food and water contained within those containers, especially if those containers are subject to high heat.

People are concerned about it because it has been linked to cancer in humans, as well as other conditions. The chemical is thought to be an endocrine disruptor that has been linked to cardiovascular disease, high blood pressure, and diabetes. 

When plastic containers get hot, BPA is more apt to leech into the food or liquid. When you’re eating or drinking from these containers, you’re more likely to also consume the chemical. 

Bottled water, even unopened, can be at risk of this happening.

Bacteria Can Grow In Warm Moist Environments

While bacteria might not grow in an unopened bottle of water, as it is a sterilized environment if you’ve opened the bottle and drank from it even once, there is a greater risk of contamination. 

However, one person thought that it couldn’t be that bad and took her opened water bottle for testing.

They found that the opened water bottle had very unsafe levels of bacteria and coliform, which provided the perfect environment for E.coli to breed. And because it is hot in the car during the summer, they can multiply that much quicker.

But in unopened bottles, they found nothing. This suggests that bottled water might not be as unsafe as previously thought. However, do you want to take that risk?

How Long Does Bottled Water Last Unopened

Depending on the weather, bottled water can safely stay in the car for up to one day. After that, bottled water becomes at risk for bacteria and BPA contamination. However, if the weather is cooler, it might be safe for up to a week before you need to remove it. 

But when researchers tested the unopened bottles, only one had BPA contamination, while the rest were perfectly safe to drink from. However, you may not want to take that risk. 

Let’s look at some alternatives that you can buy without risking BPA or bacterial contamination.

Frequently Asked Questions

How long can you keep bottled water?

According to the US Food and Drug Administration, bottled drinking water doesn’t require an expiration date. We recommend to use the standard best practices and to consume the bottled water within 2 years from the date of manufactured.

Does bottled water last forever?

No, Bottles water can get contaminated by the toxicity of its container and depending on how it was stored. Direct sunlight can change the cv We highly recommend consuming during the 2 year of manufacturing date.

What is the shelf life of unopened bottled water?

Packed bottled water shelf life is by manufacturer mentioned expiration date or best by date. To avoid any consequential health ailment, it is best to consume the bottled water within 2 years from the date of manufacture.

What happens if you drink expired water?

If the water is unopened bottle most likely the water is consumable. Storage and conditions can vary, we recommend to drink water before best of date.

Alternatives To Plastic Water Bottles

Now that you’ve seen that plastic water bottles are not safe when kept in the car, what other alternatives are there that you can use? 

You can use metal or non-BPA reusable water bottles with ice to keep your water cold.

Some water bottles can keep liquids cold for up to 24-48 hours and hot for up to 24 hours. These bottles have double-wall insulation so that anything you put in them stays the way you keep it until you either drink it or throw it out.

What about keeping them in the car? Since these bottles can keep things cold for so long, there’s no risk of bacteria growing in the water as long as you have ice. There’s also no risk of BPA leaching into your water since there’s usually no BPA plastic in either alternative.

Let’s take a look at these alternatives and what to look for.

Metal Water Bottles

Metal water bottles have come a long way since the days of the army metal canteens. 

They are quickly becoming the “go-to” material for water bottles. Most metal water bottles are insulated, which means that your beverages will stay cold for up to 24-36 hours and stay hot for at least 12 hours.

For example, the Glink Stainless Steel Water Bottle from comes complete with a straw and spout lid. You can choose whichever lid you want, depending on what you’re drinking. It keeps liquids piping hot for up to 12 hours and ice-cold for up to 24 hours, even in the car.

Since it is stainless steel, it doesn’t have BPA in the bottle. And it won’t rust even after years of use.

Non-BPA Plastic Water Bottles

Nalgene Tritan Wide Mouth BPA-Free Water Bottle
  • For Your Everyday Adventures! Take your Nalgene bottle to the gym, office, camping, exploring, and everywhere in between.
  • This Nalgene water bottle is completely leakproof, made of virtually indestructible BPA-free Tritan, easy to clean, and dishwasher safe on the top rack.
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If you like plastic water bottles, you might want to look for those that aren’t made with any plastics containing BPA. For example, the Nalgene Wide Mouth Water Bottle from is made with 50% recycled plastic destined for the landfill. 

It is leak-proof, impact-resistant, and can hold up to 32 oz (900 ml).


As you’ve seen from this article, unopened bottled water that was left in a hot car can be a health hazard. Yet, from some studies, it might seem that it’s fine if it was never drunk, as it doesn’t have the bacteria from someone’s mouth.

Still, it might be a better idea to buy an insulated water bottle made from non-BPA materials and use ice water instead. In fact, you can leave a metal or non-BPA water bottle filled with ice water in the car for quite some time without any adverse effects.

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