Well, NewMexiKen got that one wrong

In an earlier post on Stuff you need to know NewMexiKen advised against reusing certain plastic water bottles. The information I had — from a magazine — was wrong. Thanks to commenter Bob, I followed up. Here’s better info.

Question: What do you make of this recent email warning that claims dioxins can be released by freezing water in plastic bottles?

Answer: No. This is an urban legend. There are no dioxins in plastics. In addition, freezing actually works against the release of chemicals. Chemicals do not diffuse as readily in cold temperatures, which would limit chemical release if there were dioxins in plastic, and we don’t think there are.

Question: So it’s okay for people to drink out of plastic water bottles?

Answer: First, people should be more concerned about the quality of the water they are drinking rather than the container it’s coming from. Many people do not feel comfortable drinking tap water, so they buy bottled water instead. The truth is that city water is much more highly regulated and monitored for quality. Bottled water is not. It can legally contain many things we would not tolerate in municipal drinking water.

Having said this, there is another group of chemicals, called phthalates that are sometimes added to plastics to make them flexible and less brittle. Phthalates are environmental contaminants that can exhibit hormone-like behavior by acting as endocrine disruptors in humans and animals. If you heat up plastics, you could increase the leaching of phthalates from the containers into water and food.

Johns Hopkins Bloomberg School of Public Health

Will a plastic bottle leach harmful substances into water if I reuse it?
Most convenience-size beverage bottles sold in the U.S. are made from polyethylene terephthalate (PET). The FDA has determined that PET meets standards for food-contact materials established by federal regulations and therefore permits the use of PET in food and beverage packaging for both single use and repeated use. FDA has evaluated test data that simulate long-term storage and that support repeated use.

When consumers choose to refill and reuse convenience-size plastic bottles, should they be concerned about potentially harmful bacteria?
Not if they clean their plastic bottles between uses just as they would other drinking containers. Plastics are by nature extremely sanitary materials, and plastic bottles are no more likely to harbor bacteria than other kinds of packaging or drinking containers. Bacteria thrive in warm, moist environments. Once bacteria have been introduced, virtually any drinking container (coffee mugs, drinking glasses, serving pitchers, etc.) becomes a suitable environment for bacterial growth.

Consumers should clean any drinking container with hot soapy water and dry thoroughly between uses. Bottles specifically designed for extended reuse are often made with wide openings that allow consumers to use cleaning instruments and easily dry them.

FAQs: The Safety of Plastic Beverage Bottles