Being semi-athletic and somewhat health conscious, I try to drink a lot of water. Years ago, I used to drink water out of a two-liter bottle and refill it when it was empty. I’d try to make each bottle last as long as I could, and when it inevitably got lost or accidentally recycled, I’d buy another one and start over. The longest I ever made a bottle last was six months. I was pretty proud of making that bottle last so long until I read an article discussing the toxic potential of such re-use.
The chemical name of the plastic in most two-liter bottles, marked with the recycling code of #1, is polyethylene terepthalate (PET or PETE). It’s a great material, with excellent mechanical properties such as being strong, clear, easy to recycle and impermeable to most gases. Because of these desirable properties, PET is the most common bottling plastic in the United States, used to package a huge number of products, including water, pop, juice, sports drinks and condiments.
There’s only one downside to PET and it’s very important that everyone knows what it is.
When the inside surfaces of PET bottles are exposed to conditions like being left out in the sun, heated or contacted with oxygen (in air) for extended amounts of time, there is a potential for the release of very small quantities of phthalates and antimony. These nasty little compounds have been linked with a number of adverse outcomes and are known endocrine disruptors. An endocrine disruptor is a chemical with the ability to interfere with the normal functioning of both male and female reproductive systems.
A recent article by Leonard Sax in the Journal of Environmental Health Perspectives highlights the need for more research into PET and its potential for releasing endocrine disruptors into the liquids it commonly contains. Various methods of detecting such undesirable compounds yield some contradictory and inconclusive results, but the need for further study is clear.
Given the widespread use of the material to package the products many people consume every day, it’s important scientists develop a more complete understanding of endocrine disruptor release and how to guarantee such processes are not compromising the safety of consumers.
In the meantime, there’s no need to stop drinking from PET bottles. There have been studies in the past that confirmed the safety of the plastic, and under the most common circumstances there is no reason for concern. Taking a few precautionary steps is sufficient for everyone’s protection until further scientific review is completed.
First, don’t heat up liquids in PET bottles. This is most important for people with babies, and anyone bottle feeding should avoid PET (look for the #1 recycling code) until further studies conclusively prove their safety for use in this manner. Heating is also a matter of concern for people who hike in the mountains and sometimes put very hot water into their PET Nalgene-type bottles.
Second, don’t re-use your Gatorade bottle for months on end. It’s OK to refill it a handful of times, but don’t make it go the distance. There are PET recycling bins distributed throughout campus and at Peters Recreation Complex, so if you’re in doubt, drop the old bottle and get a new one. The last precaution is to avoid drinking from bottles that have been exposed to the sun for long periods of time.
If you find a bottle in the backseat of your car that’s been in there since last summer, put it in the trash instead of in the fridge. And if you’re in a backwoods gas station with PET bottles that have been there for years, buy a drink in an aluminum can or a glass bottle instead.