Polyethylene Terephthalate, commonly known as PET or PETE, is the plastic resin identified by the recycling code #1 and is widely used for single-use beverage and food containers. PET #1 is BPA-free because Bisphenol A (BPA) is not used as a building block in its manufacturing process. The chemical composition of PET makes it distinct from plastics that contain BPA.
The Chemical Composition of PET
Polyethylene Terephthalate is a polymer, a large molecule made up of many repeating smaller units called monomers. The specific monomers used are Terephthalic Acid (or Dimethyl Terephthalate) and Ethylene Glycol. These compounds react in a process called polycondensation, forming the long polyester chains that give PET its properties. This structure is fundamentally different from plastics that contain Bisphenol A. For example, Polycarbonate (PC) plastic relies on BPA as an essential building block. PET is a polyester, while polycarbonate is a different class of thermoplastic. The manufacturing process for PET involves the use of a catalyst, most often Antimony Trioxide, which remains in the finished plastic. This confirms that Bisphenol A is not part of the material’s backbone.
Health Implications of Bisphenol A
Consumer concern about Bisphenol A stems from its classification as an endocrine-disrupting chemical (EDC). An EDC is a substance that can interfere with the body’s hormone systems. BPA’s molecular structure is similar to estrogen, allowing it to mimic or interfere with natural hormones. Exposure to BPA has been linked to potential health issues, including effects on the reproductive system, metabolic function, and brain development. Research suggests links between BPA exposure and increased risk of high blood pressure, type 2 diabetes, and cardiovascular diseases.
Regulatory bodies, such as the U.S. Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA), have assessed BPA safety. While the FDA maintains that low levels found in foods are safe, the EFSA recently lowered its acceptable daily intake level significantly, reflecting persistent public health interest in minimizing exposure.
Safety Concerns Beyond BPA in PET #1
While PET #1 is free of Bisphenol A, its usage involves other chemical and practical concerns. The most discussed chemical issue involves the leaching of Antimony Trioxide, the catalyst used during PET production. Antimony concentrations in packaged contents can increase over time, particularly when stored at high temperatures or exposed to sunlight. Studies have shown that antimony levels in bottled water can rise, sometimes exceeding certain drinking water standards, especially after prolonged storage above 45°C. The risk of chemical migration is low under normal room temperature storage conditions, but it is significantly influenced by heat.
A more common concern with reusing PET #1 containers is the risk of microbial contamination. Physical degradation from repeated washing and use can create micro-fissures in the plastic surface. These small cracks can harbor bacteria and biofilms, making bacterial buildup a greater practical health risk than chemical leaching under typical reuse conditions.
Where Bisphenol A Is Commonly Found
To reduce exposure to Bisphenol A, consumers should know which products commonly use the chemical. The primary source of BPA in consumer products is Polycarbonate plastic, often found in reusable hard plastic items like large water jugs and food storage containers, and typically identified by resin code #7. BPA is also used in epoxy resins applied as a protective liner inside most metal food cans and jar lids, which can allow trace amounts to leach into the contents.
Consumers can choose alternatives to avoid BPA exposure entirely. When selecting materials, look for the following BPA-free options:
- Alternatives like glass, porcelain, or stainless steel for food and beverage storage.
- Plastics with resin codes #1 (PET), #2 (HDPE), #4 (LDPE), or #5 (PP).
Products explicitly labeled “BPA-free” are also available, though this labeling does not always indicate the absence of other similar compounds.