My stepmom is a very health conscious consumer and avid reader of this blog - I mean, yes, of course, she's biased ;) Anywho, she recently went on a weekend trip with her friend to the beach. And her friend had a disposable plastic water bottle with her, and kept refilling and reusing it. After her trip, my stepmom said, that's not good right? [My answer was, yeahhh...no, it's not good.] And she went on, Do you have anything I can share with her about this? I've written a lot about plastic, and water bottles, and heated plastic ad nauseum, but actually haven't yet written specifically about the issue of re-using disposable bottles.
Let's go ahead and tackle that topic.
First, to clarify, here we'll be talking specifically about disposable bottles for water, soda, and juice - like the ones from vending machines and grocery store aisles. These tend to be made from plastic #1 (polyethylene terephthalate, which you've probably seen more often as PET or PETE). The upside of PET is that it is BPA-free.
And these bottles are generally considered safe for one-time use, if not the most environmentally friendly. However, at least 80 of the chemicals used to manufacture these water bottles are known contaminants, and while it is unknown how many actually leach into the water you drink, according to the Environmental Working Group (EWG), "Numerous scientific studies have shown that some definitely can. They include formaldehyde, acetaldehyde and antimony."
The issue of contaminants is compounded with re-use, which may cause the plastic to soften and break down (you may not be able to see it, but I can definitely remember many a plastic bottle that became more pliant with use). So, with re-use, the plastic may start breaking down and cause those chemicals, like DEHP - a known carcinogen - to leach into your beverage.
Not to mention, EWG has found disinfection byproducts, industrial chemicals, prescription drugs, and even bacteria in bottled water that they tested. Interestingly, bottled water companies are not required to share the results of their water tests, while the water coming to your taps must be tested and the results shared.
At the very least, we recommend opting out of reusing a disposable bottle. Ideally, switch to non-plastic, refillable bottles - saving money (bottled water is 300x more expensive than tap) and improving your health in the process.
Sources and Additional Resources
Dabrowska A, Borcz A, Nawrocki J. 2003. Aldehyde contamination of mineral water stored in PET bottles. Food Additives and Contaminants, Vol. 20, No. 12, pp. 1170–77.
Five Reasons to Skip Bottles Water. Environmental Working Group. https://www.ewg.org/research/ewgs-water-week/mad-monday-what-you-dont-know-may-hurt-you#.WfeQ-2iPI2w
Keresztes S1, Tatár E, Czégény Z, Záray G, Mihucz VG. Study on the leaching of phthalates from polyethylene terephthalate bottles into mineral water. Sci Total Environ. 2013 Aug 1;458-460:451-8.
Mutsuga M, Kawamura Y, Sugita-Konishi Y, Hara-Kudo Y, Takatori K, Tanamoto K. 2006. Migration of formaldehyde and acetaldehyde into mineral water in polyethylene terephthalate (PET) bottles. Food Addit Contam., 23(2): 212-8.
Reusing Plastic Bottles Can Pose Serious Health Hazards. Earth Talk. Sept 1, 2017. https://www.thoughtco.com/reusing-plastic-bottles-serious-health-hazards-1204028
Top Five Reasons to Choose Filters over Bottled Water. Environmental Working Group. https://www.ewg.org/tapwater/bottled-water-resources.php#.WfeSeGiPI2w
Tukur A, Sharp L, Stern B, Tizaoui C, Benkreira H. 2012. PET bottle use patterns and antimony migration into bottled water and soft drinks: the case of British and Nigerian bottles. J Environ Monit., 14(4): 1237-47.