On Nutrition by Ed Blonz

Safety Concerns About Reusing Plastic Bottles

DEAR DR. BLONZ: I have heard that harmful changes can occur in water bottle plastic during heating in a microwave. While I don’t microwave these bottles, I have been opting to reuse them after washing, drying and refilling them with fresh water. After this, they are put in the refrigerator. As part of my treatment, I run the bottle’s neck under an instant hot water tap to sanitize it (even though I am the only one using these bottles). Would this be considered heating the plastic and therefore harmful? I drink lots of water and reuse plastic water bottles for their portability. I want to keep doing this but want your thoughts on this subject. Thank you. -- D.M., Phoenix

DEAR D.M.: Most commercially packaged plastic water bottles are designed for a single use. These bottles, or any plastic, for that matter, should not be put in a microwave unless it specifically states that it is microwave-safe. There is an underlying concern regarding re-use that consumers will not adequately clean and dry the containers between uses. There are bacteria on our hands and mouth, and they easily get on and in bottles when used. The failure to clean and dry properly makes the bottle a convenient breeding ground for potential problems. Consider also that the narrow mouths of commercially packed water bottles make them challenging to wash and rinse. My thought is it’s best to avoid this type of re-use. If, however, you are still planning to reuse plastic water bottles, here are some reasonable strategies -- but these are not a guarantee of safety.

Give the bottle a good visual examination to make sure it is not discolored, cracked or damaged. Using a safe water supply, wash your hands thoroughly to control for the presence of bacteria. Then carefully clean the bottle and scrub with hot, soapy water using a bottle brush; rinse, and air dry. Avoid sharing bottles where the contents come in contact with the hands or mouth, allowing the transfer of bacteria. If needed, label the bottles for easy identification. Keep the container out of the sun, away from heat. I am uncertain whether the hot water tap would cause any problems. Limit re-use to a few times, then send the bottle off to be recycled.

A better option would be to use water bottles designed for re-use. Stainless steel containers would be on the top of the list, and you can find some that are double-walled to help maintain the internal temperature. There are also reusable plastic bottles. Many reusables have larger openings to facilitate cleanings between use. If opting for a plastic bottle, best to verify that it does not contain BPA (bisphenol A), an industrial chemical linked to several health problems. The FDA has banned the use of BPA in containers used for babies and children.

Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.