Is Bottled Water Safe to Drink After Sitting in a Hot Car?
Industry and health experts are actually pretty divided over the subject.
It’s more important than ever to stay hydrated, as we may be in the midst of the hottest month in recorded history! However, is that bottle of water you found on the floorboard of your car or left sitting in your center console safe to drink after sitting in the sun for several hours or more?
Single-use water bottles are made from polyethylene terephthalate, more commonly known as PET plastic. Some argue this type of plastic can leach the chemicals BPA and antimony when heated—antimony is considered a carcinogen by the International Agency for Research on Cancer, and BPA has been deemed safe by the FDA in small amounts, but it is linked to numerous adverse health effects.
A 2014 study conducted at the University of Florida found after leaving 16 different brands of bottled water in a car that reached 158 degrees for a month, only one of them possessed BPA levels above EPA regulations and trace amounts of antimony.
Even so, the lead author of this study, Lena Ma, warned against leaving bottled water in your garage for weeks, as well as in your car for a day or longer for safety reasons. But the International Bottled Water Association has said this study “misrepresents facts.”
The IBWA says BPA is not a chemical component of the PET plastic used to produce single-use water bottles and that “the consensus among these international regulatory agencies is that the current levels of exposure to BPA through food packaging does not pose a health risk.” They also noted the antimony found in the study’s samples were “minimal and well below the FDA’s health-based regulatory limit.”
Cheryl Watson, a biochemistry professor at the University of Texas Medical Branch-Galveston, agrees with Ma and her research team, telling TODAY people shouldn’t store their bottled water in places with a significant amount of heat.
“When you heat things up, the molecules jiggle around faster and that makes them escape from one phase into another,” Watson says. “So the plastic leaches its component chemicals out into the water much faster and more with heat applied to it.”
Watson also says this is likely why the bottled water tastes different than it does chilled.
The Bottom Line
There’s a lot of back and forth when it comes to whether or not we should be drinking warm water bottles we find in our car—or store packages of bottled water in our garage—but it sounds like while there’s no good reason for it to become a habit, it wouldn’t be the worst thing if you were in a bind. We’re not sure why you would drink warm bottled water if you had other options, but if you’re into that sort of thing, try to keep it to a minimum!
We also advise for more sustainable options, such as reusable water bottles made from stainless steel or glass. Reusable water bottles make less of an environmental impact and could possibly put you at lower risk for chemical contamination. That’s a win-win in our book!