Ann Wong
July 19, 2013

Will Drinking Bottled Water Left in a Car Give You Cancer?

I stumbled upon this post shared on a friend’s Facebook timeline warning women not to drink bottled water left sitting in a warm car:

“Sheryl Crow went on the Ellen Show and said that bottled water left in the car was what caused her breast cancer. Sheryl Crow’s oncologist told her that women should not drink bottled water left in the car. The heat reacts with the chemicals in the plastic of the bottle which releases dioxin into the water. Dioxin is a toxin increasingly found in breast cancer tissue. Dioxins are highly poisonous to cells in our bodies.”

I wanted to know whether there was any truth to this claim — after all, even before reaching our own hot cars, water bottles are shipped in the back of hot trucks. So I dug a little further.

It turns out although Crow has suggested people avoid drinking out of heated water bottles, she’s never linked them or dioxin to her breast cancer.

This myth has been circulating in various forms since 2007 and started out based on emails about a college student’s thesis, which claimed that alleged carcinogen DEHA is found in water bottles.

The American Cancer Society has posted this fact on its website:

“In fact, DEHA is not inherent in the plastic used to make these bottles, and even if it was the U.S. Environmental Protection Agency (EPA) says DEHA ‘cannot reasonably be anticipated to cause cancer, teratogenic effects, immunotoxicity, neurotoxicity, gene mutations, liver, kidney, reproductive, or developmental toxicity or other serious or irreversible chronic health effects.’ Meanwhile, the International Agency for Research on Cancer (IARC), says diethylhexyl adipate ‘is not classifiable as to its carcinogenicity to humans.'”

Via: Facebook

Via: Facebook

Studies completed by the FDA found plastics used in water bottles and the hazardous materials migrating from the plastic pose no significant risks on human health. Unlike some other types of plastics, disposable water bottles don’t contain bisphenol A (BPA).

And according to Dr. Rolf Halden of the John Hopkins Bloomberg School of Public Health, we actually face a much greater risk from potential exposure to microbial contaminants (germs) in bottled water than from chemical ones.

The lesson here is to take all Facebook posts and chain emails with a grain of salt and do some research before we go off on another cancer scare. This isn’t to say water bottles are 100 percent free of contaminants (many do contain phthalates) or chemical leaching never happens, but the amounts are so minute that it’s not as toxic as the post claims.

The safest bet is to dispose of your water bottles after a couple use or refills rather than allowing germs to breed — or buy yourself some good quality reusable metal or glass bottles and use those instead.