Plastic Water Bottles exposed to Heat can be Toxic

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 Plastic water exposed to heat can be toxic



Takeaway First

Don’t drink water from plastic bottles left in a hot place for a long time. Chemicals in plastics, mainly antimony (Sb) and Bisphenol A (BPA) can leach into any liquid in a plastic bottle according to new research, and those chemicals  can potentially cause diseases (such as cancer) when consumed, based on other research.

Study Details

•    16 plastic water bottles were exposed to different temperatures: 39°F (4°C), 77°F (25°C), and 158°F (70°C).
•    Levels of BPA and antimony were checked after one, two, and four weeks.
•    Antimony concentrations in the water from plastic water-bottles averaged 3.18 ng/L at 39.2°F (4°C), and 6.88ng/L at 77°F (25°C).
•    At 158°F (70°C) (about the temperature in a car on a hot summer day), levels of antimony in water increased significantly to 38.5 ng /L.
•    Levels of antimony in one of the sixteen water bottles increased to 2604 ng/L.

What does this mean to you?

The surge of plastic as a commodity was highlighted in the 1967 film The Graduate. Do you remember The Graduate, starring a young Dustin Hoffman as Benjamin? There is a scene in this film where Benjamin, a recent college graduate with no well-defined aim in life, is pulled aside by a businessman, Mr. McGuire, where this dialogue takes place:
Mr. McGuire: I just want to say one word to you. Just one word.
Benjamin: Yes, sir.
Mr. McGuire: Are you listening?
Benjamin: Yes, I am.
Mr. McGuire: Plastics.
Benjamin: Exactly how do you mean?
Mr. McGuire: There’s a great future in plastics. Think about it. Will you think about it?

Indeed, plastics is big business.  But what is the real price of this cheap material?

Virtually all plastic water bottles are made from polyethylene terephthalate (PET) and typically contain 190–300 mg/kg of antimony. Bottled waters become contaminated during storage due to a release of antimony from PET plastic. Actually, almost all packaged drinks are made from PET plastic.  This includes milk, coffee, and acidic juice, among types of food containers.

I am guilty of leaving water bottles in my car, but this past summer I wised up and left them in a cooler filled with ice.  And yes, I changed the ice weekly after it melted. The temperature in the car can reach 167°F (75°C) at an ambient temperature of 91°F (33°C) in the summer.  This research shows that storing water in plastic bottles at high temperatures may enhance contaminant release into water from PET bottles.

Antimony (Sb)

Antimony is classified as a possible carcinogen to humans by the International Agency for Research on Cancer.  Long-term exposure to elevated antimony can also lead to increased blood cholesterol and decreased blood sugar.

A guideline value of 20 µg/liter (rounded figure) can be derived from this TDI by assuming a 60-kg adult drinking 2 liters of water per day and allocating 10% of the TDI to drinking-water. It should be noted that this value could be highly conservative because of the nature of the end-points and the large uncertainty factor; further data could result in a lower uncertainty factor.

Bisphenol A (BPA)

BPA in all sixteen bottles rose significantly amount increased at 158 F (70 C) to an average of 23.4/ ng/L.

BPA is a key ingredient in modern plastics found and the inner lining of canned foods, and it may act as hormone disrupter where synthetic chemicals called xenoestrogens (synthetic estrogen) mimic estrogen and attach to estrogen receptors (fooling the body into thinking its estrogen). This process interferes with the normal functioning of hormones. One study in prostate cancer cells showed that very low concentrations of BPA activated the androgen receptor and initiated proliferation of cancer cells, independent of testosterone (Wetherill et al. 2002).

BPA is found in plastics and canned goods. Canned goods of tomato sauce, vegetables and soups may contain the chemical in the inner lining called epoxy resins to avoid corrosion of the metal. Epoxy resins are filled with BPA.

BPA enters the body when, let’s say, a plastic water bottle, is washed, heated or stressed, allowing the chemical to leach into the liquid and then enter the body.

Taking Action

Let’s be real here, I am going to drink water from a plastic bottle at some point. But I will continue to be cautious, as I want to maximally reduce my chances of succumbing to cancer and other life threatening diseases.  I think this is a holistic but realistic approach. So, here’s what to do.

•    Decrease exposure:  Plastic bottles have a recycling code at the bottom of the bottle that looks like a triangular arrow around a number.  Avoid these numbers: 3, 6 and 7. Plastics especially with the Number 7 contain BPA.
•    Avoid canned foods. They are often void of nutritional value and can have BPA leach into the food.  Use glass container to store food. Note: glass containers do not contain BPA chemical but tops used to close glass containers do.
•    Avoid purchasing either canned salmon or canned sardines in vinyl-lined cans that contain BPA.  We recommend contacting the manufacturers of these products to find out which ones use BPA-free cans.  If you cannot find BPA-free cans, you may want to consider purchasing the fish in another (non-canned) form.  Vital Choice  offers an excellent assortment of wild BPA-free fish and sardines.

Big Don’ts
•    Don’t microwave food or drinks in plastic containers—even if they claim to be “microwave safe.” Heat can break down plastics and release chemical additives into your food and drink.  Microwaves heat unevenly, creating hot spots where the plastic is more likely to break down.
•    Don’t use plastic containers for hot liquids—only cool liquids if at all.
•    Don’t reuse single-use plastics. They can break down and release plastic chemicals when used repeatedly.
•    Don’t use old plastic water bottles. Exposures to plastics chemicals may be greater when the surface is worn down.
•    The big don’t of course is this: don’t leave water in plastic bottles in your car.

•    Wash plastics on the top rack of the dishwasher, farther from the heating element, or by hand. This will reduce wear and tear.
•    Bring your own mug for coffee to the office and to your coffee shop, and use that instead.
•    Bring drinking water from home in glass water bottles instead of buying bottled water.  Or, buy glass bottled water –  Mountain Valley Spring Water is an excellent brand.
•    Store foods in the freezer in glass mason jars and not in plastic bags.
•    Use stainless steel or high-heat-resistant nylon for utensils in lieu of plastics.


Westerhoff, P., Prapaipong, P., Shock, E., Hillaireau, A. (2008). Antimony leaching from polyethylene terephthalate (PET) plastic used for bottled drinking water. Water Res. 42: 551–556.

World Health Organization. Water Sanitation Health: Antimony in drinking water.  Accessed 1 October, 2014.

Fan YY, Zheng JL, Ren JH, Luo J, Cui XY, Ma LQ. (2014). Effects of storage temperature and duration on release of antimony and bisphenol A from polyethylene terephthalate drinking water bottles of China.  Environmental Pollution 192:113-20.

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by Dr. Geo

20 comments… add one
  • André 10/10/2014, 6:40 AM

    As always, great advise. Thank you for the time and energy you expend to guide us through the minefield. Your blog is a must read.

  • C.W.2 10/10/2014, 5:26 PM


    Let’s hope that this article’s caveat does not extend to polyhydroxyalkanoate, which forms a biodegradeable plastic for use in the medical community.

  • richard manser 11/03/2014, 1:31 PM

    “Unrelated” What’s your take on Chlorophyllin ?

    • Dr. Geo 11/10/2014, 10:46 AM

      Anything with chlorophyll is a good thing.

  • Ruth Petrie 11/04/2015, 4:10 PM

    I have been using reusing old gatoraide bottles with the twist top for about 5 years now as a to go coffee mug. It has the #1 PET on the bottom. I on occasion have put it in the microwave to heat it up if it gets cold. Obviously I was under the impression that if it was #1 it was safe to use. I will be changing my habits after reading your article. My question is do you think any damage has been done already.

    • Dr. Geo 11/16/2015, 3:25 PM

      Hard to tell, Ruth. Likely not but hard to tell.

  • Tony 08/05/2016, 10:33 AM

    I have always been cautious about using water bottles. I only use any type of plastic stored drinks on rare occasions. As of now I have used plastic water bottles for about 6 months due to military duty in a deployed location. They have pallets of water just sitting outside getting direct sunlight at least 120 F. when ever your are running low on water you go grab a box. I stuck my hand in one of these boxes and it was hot enough that it hurt my hand. I am afraid of all the chemicals my body and other people are consuming. Sometime to me the water taste funny, when that happened I throw it out and grab another.

  • xeno 08/27/2016, 3:08 PM

    It’s frustrating reading articles that don’t post a date and the only indication of how old the article is can only be determined by the lack of current information or out dated statements. Even then it’s hard to tell.

    We don’t know if the 16 bottles were old or new updated style, what #(1-7?) they were or even how old they were to begin with. We don’t know if they were food grade or not. Either the study or the report was poorly done. Did Michael Moore do the study? Is what comes to mind.

    Statements like “according to new research” w/o a date are key flags. It turns out the study is from various months in 2014 and since they did mention BPA they probably used non food grade bottles. But again that’s just another guess to add to the others.

    Looking further at the study it seems it was done on Chinese bottles at China’s Nanjing University and the U of Florida has some unknown connection.

    Since this article is mainly focused on antimony, my question would be is if antimony is in #1 PETE bottles or was it taken out like the BPA

    The best part is there is great information here that’s very useful and the part about leaving water bottles in the car completely slipped by me. In this 112 deg. summer our cars get to 145 deg +\- according to the gadget I used. Also I never knew about antimony before and since it mentions a cautious possible link to maybe contributing to cancer (not too convincing), I’d like to steer clear of it to be on the safe side.

    For our situation, glass isn’t an option due to cost, danger(breakage) and a few other issues. Can you imagine the millions of people that use plastic bottles changing to glass like the good old days decades ago? Our streets nature are still littered with broken glass in spite of the transfer to plastics with litter even more and cost tremendous amounts in oil and other resources. Yes, that’s a lot to over think isn’t it?….. or is it? 😉

    One thing for sure is NEVER cook in plastic, just don’t do it. Also China has given ample history and reason to not trust their products as far as ingestible transfers from items (dishware, toys etc). I don’t buy glass for cooking etc. that’s made in china.

    Time to go do something else, thanks for the article.

  • Tim 04/17/2017, 3:45 PM

    I recently became wiser to the harm of plastic water bottles. I bought some glass water bottles and I bought one of the 5 gallon water bottles that flip upside down on a water dispenser. Those say PETE 1 on them but to my knowledge are to used multiple times. What are your thoughts on that?

  • charlie howard 05/17/2017, 1:04 PM

    my concern is that I continue seeing gas stations with plastic cases of water outside the gas stations. these cases sit in the heat for days/weeks/months. I continue seeing people buying water that sits outside these gas stations. Is there anything/anyway this can be done at a national level? This is a national health concern. Adults and children are drinking these waters. I live in Brownsville Texas. It is currently 98 degrees. The gas station closest to me is less than a mile. It has about 40 cases of water sitting outside. The cases are full of dust and people, especially people that work outside buy these cases. I guess because they are easier to reach.

  • Brian 06/06/2017, 10:08 PM

    How long is ‘long time’ in the sun?

    • Dr. Geo 06/18/2017, 8:22 AM

      Its different for everyone, Brian, it depends on complexion. All one needs is 2o minutes a day.

  • Richard Ambre 06/12/2017, 12:14 AM

    Thank you so much, how long have we been drinking water out of water bottles and now you tell us this. SHAME on all of you chemists and water bottle manufactures. As for one, I think a class action law suit is in order on every one for manufacturers to company chemists. What responsibility do you think you have to the public at large not to mention yor responsibility to mitigate any problems and now you mentioned heat after 20 years. SHAME on the lot of you.

  • RUDY VELIK 08/02/2017, 11:46 PM


    • Dr. Geo 09/16/2017, 10:41 AM

      Rudy, that is high temperature and I assume there is leakage from the plastic in your bottle.

  • Chrys 08/18/2017, 5:12 PM

    I once drove around to the back of a store and sitting at the back of their lot were several skids (pallets) of cases of bottled water… sitting out in the open without so much as a tarp. It was June and the outside temperatures where hitting the upper 90’s (celcius). It struck me that all those cases will end up being purchased, perhaps months down the road by the unsuspecting public. We have so many regulations in place governing the safe handling of food – what about the safe storing of containered foods? None apparently. I’ve never purchased a plastic bottle of anything since that day.

  • Don 09/03/2017, 10:07 AM

    The problem with the study is the time frame. Who is going to leave their water bottles or plastic containing food to heat for weeks at a time up to 4 weeks? And then drink out of it… Not only would that be gross but instead of worrying about some chemical you probably have to worry about a pathogen.

  • Amos K Onokpise 08/02/2018, 1:40 AM

    Nice reading through your posts responses, some good lessons learned here. My question is, what is the impact of using harden plastic containers for boiling hot water or a plastic tea kettle? and at what temperature will be harmful to use it?

    • Dr. Geo 08/07/2018, 8:08 AM

      I would NOT take any consumable substances from plastics that are exposed to heat.

  • Cindy 08/17/2018, 4:29 PM

    I recently stopped buying bottled water from grocery store, delivery instead. I receive pete 1 which company told me is bpa/pvc/phthalate free. Unfortunately glass bottles are not available bin nc. My confusion is if #1 shouldn’t be heated or reused why are these bottles being washed for reuse 50 times before recycling.
    Water services response is “we adhere to fda regulations” (eek!)
    Of course I’m still waiting on FDA to return call. (Day 4 three voicemails still waiting).
    I’m sure there is a simple explanation.


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