If you’ve been following the current toxic plastic avoidance advice, you know that recycling category #1 (PET) has been considered a safer choice. We know it’s BPA-free, so we just use it once and recycle it, right? Well, that assumption may be wrong.
What is PET and Where is it Found?
Polyethylene terephthalate (PET) is the main ingredient in most clear plastic containers used for bottled water, soda, sports drinks, and condiments such as vinegar and salad dressing. PET bottles are also commonly used for the packaging of cosmetic products, such as shampoo, particularly when such products are sold in clear plastic bottles.
Does PET Leach Endocrine Disrupting Chemicals?
In a review published by Environmental Health Perspectives, Leonard Sax investigated evidence that bottles made from PET may leach various endocrine disrupting phthalates. He also considered evidence that leaching of antimony from PET containers may lead to endocrine-disrupting effects, but we’ll talk more about that in an upcoming article.
As you’ve probably noticed, “phthalate” is actually part of the PET name “polyethylene terephthalate” which begs the question about the plastic’s chemical makeup. In response, the plastics industry has emphasized a distinction between PET and phthalates. In a letter to Environmental Health Perspectives (EHP), a spokesperson for the American Plastics Council wrote:
Plastic beverage bottles sold in the United States are made from a type of plastic known as polyethylene terephthalate (PET). Although polyethylene terephthalate (the plastic) and phthalate (the additive) may have similar names, the substances are chemically dissimilar. PET is not considered an orthophthalate, nor does PET require the use of phthalates or other softening additives. (Enneking 2006)
But is there more to the story? Mr. Sax says there is. He asserts that the available research suggests that phthalates are present in PET bottles, and that the concentration varies according to several factors:
- Phthalates leach from the plastic into lower pH products such as soda and vinegar more readily than into bottled water
- Temperature also appears to influence the leaching both of phthalates (and antimony), with greater leaching at higher temperatures
- Combining both variations of low PH and high-heat exposure could result in an even higher leaching of phthalates
- Variations in the composition and manufacture of PET may also influence the leaching of these substances into the contents of the bottle. PET is typically a homopolymer, but some copolymers are also categorized as PET (copolymers have been found to be less vulnerable to degredation, thus leaching less)
The author concludes that the evidence suggests PET bottles may yield endocrine disruptors under conditions of common use, particularly with prolonged storage and elevated temperature. And because of the widespread use of PET plastic worldwide, more research is needed to clarify how PET containers may be contaminated by endocrine-disrupting chemicals.