Polyethylene terephthalate, or PET 1, is the most common plastic used for single-use food and beverage containers globally. The number “1” inside the triangular recycling symbol identifies this material, which is also sometimes labeled as PETE. Given its widespread presence, consumers often question its safety for storing consumables. Clarifying the science behind its chemical makeup and regulatory status provides a clear picture of its associated risks and benefits.
Defining PET 1 Plastic
PET 1 is a type of thermoplastic polymer favored by manufacturers for its unique combination of properties. The material is remarkably lightweight, yet it possesses high strength, impact resistance, and excellent clarity, making it an ideal substitute for glass in many applications. Its ability to create a strong barrier against gases like oxygen and carbon dioxide helps maintain the freshness and carbonation of beverages over time.
This material is used extensively beyond just water and soft drink bottles. PET 1 is also commonly thermoformed into clear, rigid containers for items like peanut butter, salad dressings, cooking oils, and single-serving food trays. The low production cost and ease of molding contribute to its popularity as the preferred packaging material for many consumer goods.
Chemical Components and Health Concerns
The primary health concern related to PET 1 involves antimony, a metalloid used as a catalyst during the manufacturing process. While the final plastic product is mostly the stable PET polymer, trace amounts of this catalyst remain embedded within the material. Under certain conditions, this residual antimony can migrate, or leach, into the contents of the container.
Studies have shown that the concentration of leached antimony in bottled water is typically very low at room temperature, but this migration rate increases significantly when the plastic is exposed to heat. For example, storing a PET bottle at temperatures around \(60^\circ\text{C}\) (about \(140^\circ\text{F}\)), such as inside a hot car, can cause antimony levels to rise over time. While the resulting concentrations generally remain below the maximum limits set by most international health organizations, the possibility of exceeding stricter localized standards exists under prolonged high-heat exposure.
PET 1 does not contain Bisphenol A (BPA) or common phthalates used as plasticizers. Unlike polycarbonate plastics, which require BPA in their production, PET is synthesized from terephthalic acid and ethylene glycol, a process that does not involve BPA. Since PET is a naturally rigid plastic, it does not require softeners like phthalates, eliminating these two common chemical concerns from the discussion of PET 1 safety.
Official Safety Assessments and Usage Recommendations
The U.S. Food and Drug Administration (FDA) and similar regulatory agencies globally have authorized PET 1 as safe for food and beverage contact for decades. Regulators classify PET as an “indirect food additive” and continuously monitor its use based on scientific testing that simulates real-world conditions. This oversight is based on the principle that any substance migrating from the plastic must not pose a health risk.
The FDA sets a strict threshold for chemical migration, deeming a dietary intake of \(1.5 \mu\text{g}\) per person per day as a negligible risk. Testing on PET 1 confirms that the migration of its components, including antimony, falls far below this level when the plastic is used as intended.
Consumers can minimize potential chemical migration risks by following a few simple guidelines. It is advised to avoid exposing PET 1 containers to high temperatures, such as leaving them in direct sunlight or hot vehicles. Furthermore, PET 1 containers are not designed for repeated use, as physical wear and tear can potentially increase the rate of chemical leaching and encourage bacterial growth.