How Dangerous Is Bottled Water?

Many of us have doubts about bottled water. It seems like every day new information is revealed that sheds doubt on its safety. And many things about bottled water are confusing. Some brands of bottled water have expiration dates on their labels. Does bottled water expire? Does it go bad? Are there chemicals or other dangerous things in the water? And what about microplastics or other things leaching from the plastic? In this article, I answer all these questions and more.

Does Bottled Water Expire?
Why Are There Expiration Dates On Bottled Water?
Opened Water Goes Bad
Are There Harmful Chemicals In Bottled Water?
Microplastics In Bottled Water
How Do Microplastics Get Into Bottled Water?
Do Microplastics Harm Your Health?
Is Bottled Water Really Safe To Drink?
Safe Bottled Water Storage
Key Summary Points

Does Bottled Water Expire?

Bottled water, in the United States, is considered by the FDA to have an indefinite shelf-life. In other words, it doesn’t expire or go bad. The taste will change over time and a ten-year-old bottle of water probably will not taste very good, but it is not considered unsafe to drink. Yet, many bottles of water have expiration dates, usually around two years from the date of manufacture. Why does water have an expiration date if it doesn’t actually expire?

Contrary to the interesting explanation found in many food listicles, these expiration dates do not exist because ‘the water doesn’t expire but the bottle does.’ While the FDA does state that long-term storage of bottled water may result in an off-odor or taste, it does not require manufacturers to put expiration dates on the bottles.

It seems odd that bottlers would place expiration dates on bottles when it is not required. The conspiracy-minded would state that it’s because they want us to throw away the bottles and buy new water! But, there is a more concrete reason for the practice.

Why Are There Expiration Dates On Bottled Water?

The reason that there are expiration dates on some bottled water products turns out to be very simple. If you see an expiration date on your bottle of water, blame New Jersey, the place you can’t pump you’re own gas or make a left turn. New Jersey is the only state to have passed a law requiring expiration dates on water bottles. This was passed in 1987. It is not clear why the state deemed this necessary.

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New Jersey is just one state so it may seem strange to put an expiration date on every bottle, no matter what state it is bound for. But, it’s cheaper. It’s easier and less expensive to just slap a date on every label than to have to change your production line mid-step for certain bottles. That would put a wrench in the works.

You will see similar irrelevant labeling on many products. For example, you may see the dreaded California Proposition 65 warning on many products, regardless if they are being sold in California or even the United States. This causes many consumers to think that the product will give them cancer, cause birth defects, or reproductive problems, even though it’s only there to satisfy an absolutely ridiculous requirement that manufacturers warn consumers if a product contains one of 900 chemicals that the state has decided to put on it’s cancer-related (etc.) substances list, even though not all of them are known human carcinogens.

It’s easier for some companies to place this warning on their labels regardless of where the product is being sold. And, you will see this warning on Amazon quite often. It is almost guaranteed that many small companies just provide this warning regardless of whether they know that one of these chemicals exists in the product or is used during the manufacturing process. It’s easier to give a warning than to meet the requirements.

I’ve also heard rumors of a fee being charged to enable companies to be certified to not give the warning. I do not know if this is true, however. Another example is food allergy warnings. It may be easier to put a “this product is manufactured in a facility that also processes tree nuts” allergy warning on a label than it is to make doubly sure there is no cross-contamination. On the other hand, the product may be safe, regardless. However, the New Jersey law requiring expiration dates on bottles of water was repealed in 2006.

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Even though New Jersey no longer requires an expiration date, it seems some bottled water manufacturers kept on putting the dates on their bottles. Perhaps they didn’t see any reason to change what they had been doing for decades.

According to the International Bottled Water Association (IBWA), however, “Some companies still place date-based lot codes on bottled water containers, which are typically used to assist in managing stock rotation.” A date-based lot code, to be clear, is not an expiration date, and also according to the IBWA, there was never any scientific evidence to support the use of expiration dates on bottled water. It is doubtful this practice will continue far into the future, though, making me think that few people will actually notice an expiration date on their water, wonder why it is there, and find this article. I’m curious to find out!

Opened Water Goes Bad!

Keep in mind that the FDA is careful to say that water isn’t considered to expire as long as it is bottled under current ‘good manufacturing guidelines’ and is stored in a sealed, unopened container. Once you open your bottle of water, and bacteria get into it, it certainly will go bad quite quickly. You may be concerned, as are many, about the potential for chemicals from the plastic bottles to leach into the water over time. You may also be concerned about microplastics getting into the water.

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Are There Harmful Chemicals In Bottled Water?

PET bottles which are used for almost all bottled water, have been deemed by the FDA to be safe. But, there has been some research on such harmful chemicals as antimony, a possible carcinogen that may be present in some plastic bottles. It is believed that the potential for leaching of this chemical is greater when the bottle is stored under hot conditions.

Although most studies have been performed in Europe or China, a study in the United States tested antimony leaching from water bottles in the Southwestern U.S. This area was chosen because of its high rate of bottled water consumption and its high temperatures.

Nine commercially available bottled waters were tested and antimony levels were found to be within safe limits, although higher temperatures certainly caused antimony to leach more quickly. The study found that it took bottles being stored at 150° F for 38 days for antimony levels to reach FDA limits, while at 167° it took only five days.

Another study, testing multiple bottles in China for antimony and bisphenol A showed almost no risk. To be clear, there is no BPA (bisphenol A) in PET plastic bottles used for your bottled water but antimony still could be a concern. Very little of the antimony in PET bottles ever leaches into the water, but there is still good reason to seek out alternatives that do not contain this chemical. ¹ ² In terms of leached chemicals, a typical bottle of water you purchase at the store is safe to drink, all things considered.

Microplastics In Bottled Water

Microplastics are the major problem in bottled water and something you should be concerned about. Although they are difficult to detect due to their small size, there is evidence of the presence of microplastics in human blood, lungs, gut, and feces. There is even evidence of these plastics in reproductive organs like the placenta and testes.

While there is no proof of the long-term health effects of these microplastics, it can’t be good and it’s probably a wise idea to avoid introducing more into your body. One study, supported by the National Institutes of Health used a powerful imaging technique called Raman scattering (SRS) microscopy to detect micro and nan0-plastics (nano-plastics are smaller than microplastics) on a single particle level.

The researchers analyzed three popular brands of bottled water for the presence of plastic and reported their results on January 8, 2024, in the Proceedings of the National Academy of Sciences. The study found that a liter of bottled water contained an average of 240,000 tiny pieces of plastic. About 90% of these plastic fragments were nanoplastics. This was 10 to 100 times more plastic particles than seen in earlier studies, which mostly focused on larger microplastics.

Microplastics range from 0.1 to 5,000 micrometers and nanoplastics from approximately 1 to 100 nanometers (0.001–0.1 micrometers). Many sources assume that the plastic found in bottled water comes from the bottle itself, but the plastics found in this study were all seven common types of plastic! One was polyamide, a nylon used in the filtering and purifying of water. Ironic?

Other plastics used in purification were also found, including polyvinyl chloride, polymethyl methacrylate, and polystyrene. And, of course, plenty of PET or polyethylene terephthalate, the plastic actually used to make water bottles, was found. ³

We might expect some of these same plastics to be found in bottled sodas and other drinks, as well as in packaged foods. While I would support your decision to avoid bottled water because of microplastics, it is important to point out that microplastics are present everywhere at high levels!

Microplastics and nanoplastics are formed when plastic breaks down into ever smaller particles. They are in our food. They are in our drinks. They are in our soil. They have been found in the deepest parts of the ocean and even at the top of Mount Everest. Avoiding bottled water is a good idea, but it’s a drop in the bucket.

In terms of microplastics in commercial bottled water, the jury is still out on how safe bottled water is to drink. Yes, large amounts of very tiny plastic particles have been found in bottled water. This is probably safe in the short term. However, in the long term, the jury is still out. Most probably, due to the amount of microplastics being found, bottled water should not be considered safe for longterm consumption.

How Do Microplastics Get Into Bottled Water?

Clearly, many of the plastic particles found in bottled water are their from the manufacturing process and are put into the bottle along with the water. So, nothing you do could change this. It is also not clear that the PET plastic comes from the plastic bottles themselves or from part of the manufacturing or bottling process. It has been suggested that the PET could abrade off when you squeeze the bottle or when you repeatedly screw the cap on and off during drinking.

Do Microplastics Harm Your Health?

Up until recently, there has been little direct evidence of the effect of microplastics on human health. A new study, published in the New England Journal of Medicine on March 6, 2024, provides compelling and frightening evidence that indeed, the presence of microplastics in the human body can lead to negative health outcomes.

In the prospective study, Dr. Raffaele Marfella, et al. observed 304 patients who were undergoing carotid endarterectomy for asymptomatic carotid artery disease. This means that the patients had plaque in their arteries, particularly in their carotid arteries and this plaque had built up enough to cause narrowing or “stenosis.” Therefore, surgery had been scheduled to remove this dangerous plaque and since the plaque was being removed anyway, the researchers took the opportunity to analyze the plaque for the presence of microplastics and nanoplastics and then scheduled a follow-up to see how the patients fared 34 months out.

The team analyzed plaque specimens from the patients’ carotid arteries for the presence of microplastics and nanoplastics by using several sophisticated detection methods. They found over 100 patients with plastic foreign particles such as 150 patients with polyethylene and 31 patients with polyvinyl chloride.

According to the study, “Electron microscopy revealed visible, jagged-edged foreign particles among plaque macrophages and scattered in the external debris. Radiographic examination showed that some of these particles included chlorine.”

In a 34-month follow-up, the team found that the patients with microplastics in their carotid artery plaque had a four times higher risk of myocardial infarction, stroke, or death from any cause than those with no plastic detected. ⁴

Keep in mind that this was an observational study and the researchers did not look at any other variables that could have contributed to these outcomes such as diet and other lifestyle factors. For a more thorough discussion of this study see this video from PhD physician Gil Carvalho on Nutrition Made Simple.

Is Bottled Water Really Safe To Drink?

The water you get from your household tap is probably safer, in many respects, than bottled water. Although bottled water products have not been found to contain many leached chemicals, such as antimony or BPA (PET bottles don’t contain BPA), they have been found to have large amounts of microplastics.

Not every brand of bottled water has been tested to date, but there is a good chance that any bottle of water you buy will contain on the order of thousands of minute plastic particles. Most of us will agree that having what the researchers above described as ‘jagged-edged foreign’ literally embedded in your artery walls cannot be anything but bad.

More research is needed to understand the potential danger of microplastics in human health. Regardless, reducing your exposure to microplastics is a good idea and bottled water is one potential source of these particles.

If you are very thirsty and have no other source of water to drink, an occasional bottle of water should not be cause for concern. It is safer than acute dehydration. In general, however, it is advisable to avoid bottled water.

Be aware that bottled water is but one potential source of microplastics. They are everywhere in our environment and you cannot avoid them by eliminating one product. However, an earlier study that analyzed 26 studies from around the world, Human Consumption of Microplastics by Kieran D. Cox, et al., estimated an average intake of 39000 to 52000 plastic particles per year, depending on age and sex. When the inhalation of particles is factored in, this estimate rises to 74000 and 121000. According to the paper:

…individuals who meet their recommended water intake through only bottled sources may be ingesting an additional 90000 microplastics annually, compared to 4000 microplastics for those who consume only tap water. ⁵

The infographic below from Statista shows the biggest sources of microplastics in the human body. As you can see, bottled water is the greatest source, with an average of 94 particles per liter, a much greater amount than tap water. ⁶ Recall the study discussed above, however, that found many more particles than earlier studies, with up to 240,000 particles per liter! Perhaps more frightening is the presence of microplastics in the air we breathe. You can eliminate bottled water but you cannot stop breathing.

Microplastics in huma infographic from Statista — Infographic from Statista

Safe Bottled Water Storage

If you’re not convinced that bottled water isn’t a great idea, you would still be wise to not store your bottled water in very warm temperatures such as the trunk or backseat of your car, where, during the summer, temperatures can reach well above 150°. Also do not store your water in the garage, in a storage shed, or in the attic, especially if you live in a very warm and sunny climate such as the South or Southwest. Also, when you are at the beach, do not leave your water bottles sitting under the sun all day. Keep it in a cooler or at least under shade. In general, store bottled water in a place that will keep it at room temperature or cooler. This will make it less likely that antimony or other chemicals will leach into your water.

Key Summary Points for “How Dangerous Is Bottled Water?”

Although many bottled water products have expiration dates on their labels, bottled water does not actually expire. It lasts indefinitely although it may not taste good after prolonged storage, depending on conditions.
Contrary to claims, the dates are not one the bottles because “the water doesn’t expire but the bottle does.”
The reason the bottles have dates is because of a now-repealed New Jersey law. The dates are not required but perhaps some water bottling companies saw no reason to change their labeling practices.
Some companies use date-based lot codes on bottled water containers. These are typically used to assist in managing stock rotation. A date-based lot code iis not an expiration date.
Once a bottle of water is opened, it does go bad as bacteria are introduced into the water.
There are many concerns about the safety of plastic bottles used for water and other beverages.
The PET bottles used for water are considered safe by the FDA and do not contain BPA (bisphenol A).
There are some concerns about antimony leeching from the plastic, especially in hot conditions. However, studies show antimony levels are generally within safe limits.
Proper storage of bottled water in cool conditions can help reduce chemical leaching.
Microplastics in bottled water are a major issue. Microplastic and nanoplastics have been found in high amounts in bottled water. These tiny plastic particles can come from the manufacturing process rather than the bottles themselves and may pose health risks, though more research is needed.
Tap water is generally safer than bottled water due to the microplastic issue.
Microplastics are ubiquitous in the environment, so eliminating one source of them may not make a big difference.