Is migration of antimony (Sb) from PET bottles into bottled water reason for concern?
Frequently Asked Questions Concerning PET and Antimony
What is PET and how is antimony used in producing PET?
PET, which stands for polyethylene terephthalate, is the lightweight but shatterproof recyclable plastic commonly used for consumer soft drink, juice and water bottles as well as other food and drink containers (salad dressings, mouthwash, etc.).
Antimony trioxide (ATO) is a compound of antimony that is used in small amounts as a catalyst for the manufacture of PET. Antimony trioxide occurs naturally or can be prepared synthetically from antimony ores. Antimony compounds are widely used in paint pigments, ceramics, glass, rubber, plastics and even medicines. Antimony is chemically bound into the PET polymer.
What is the safe level for antimony in drinking water and bottled water?
The U.S. Environmental Protection Agency (EPA) has established 6.0 parts per billion (ppb) as a safe level for antimony in drinking water. The U.S. Food and Drug Administration (FDA) has adopted the EPA limit of 6 ppb as a safe level for antimony in bottled water. Based on review of more recent studies, the World Health Organization has raised the guideline value for a safe level of antimony in drinking water to 20 ppb.
In light of the World Health Organization review, the new data that are available, and comments that have been made by EPA concerning antimony toxicology, the EPA may also raise its safety threshold for antimony contaminants in drinking water when reviewed in the future. Any revisions to the EPA drinking water limit would likely be adopted by the FDA as well.
As an additional point of reference, the California Office of Environmental Health Hazard Assessment (OEHHA) has established a public health goal of 20 ppb for antimony in drinking water.
What is the safe level for antimony in foods?
The European Food Safety Authority recently established a safe limit of 40 ppb for antimony in foodstuffs, assuming 1 kg of food per day.
How can I be sure that bottled water in PET plastic is safe to drink?
In the U.S., both drinking water and the containers are regulated for safety. The safety of drinking water is regulated by the EPA under the Safe Water Drinking Act of 1974, which sets maximum allowable concentrations of chemicals found in water. The safety of bottled water is also regulated by the FDA, which has regulations for bottled water (21 CFR 165) and also for packaging materials that come in contact with food (including bottled water) to determine that they are safe before they are allowed on the marketplace. Food packaging materials used for bottled water comply with applicable regulations within 21 CFR parts 170 to 199 or with an applicable food contact notification as described at:
http://www.cfsan.fda.gov/~dms/opa-fcn.html.
FDA has an explanation of bottled water regulation at:
http://vm.cfsan.fda.gov/~dms/botwatr.html.
PET has been used for food and beverage containers for nearly 30 years without any known incidences of causing adverse effects, and is approved as safe for contact with foodstuffs and drinks by the FDA. Extensive testing of PET and PET packaging has repeatedly shown it to be of very low toxicity. PET itself is biologically inert if ingested. Laboratory tests on the migration of antimony from PET have consistently indicated levels to be below thresholds for safety.
How significant are the amounts of antimony in PET bottled water?
The amounts of antimony found in PET-bottled water are insignificant and do not pose any health concern. A study of water bottled in PET containers by the Swiss Federal Office of Public Health (BAG) found an average antimony level of 0.43 micrograms per liter (µg/l). For comparison, the World Health Organization has established a recommended limit of 20 micrograms per liter (µg/l).
Should I be concerned about antimony migrating from a PET container into its contents? Has PET been studied for safety?
The antimony used as a catalyst in producing PET (from antimony trioxide or ATO) is chemically bound into the PET polymer so very little migrates under conditions of use. Thus, there is no health risk from the migration of antimony from PET. The levels of antimony in water before and after being packaged in PET are well below the safe limits established by various regulatory agencies around the world. Extensive testing of PET and the antimony catalysts used in producing PET has consistently found both to be of very low toxicity and safe for their intended uses. The use of antimony as a catalyst for manufacture of PET has been evaluated by the FDA as part of the FDA process for regulation of food packaging materials and has also been evaluated by agencies including Health Canada and the European Food Safety Authority.
I’ve heard there is a new research study showing that bottled water in PET contains toxic amounts of antimony that leaches out of the plastic. Is that true?
No. It is important for consumers to understand that absolutely no studies have found toxic amounts of antimony in bottled water in PET containers.
Unfortunately, there seems to be a great deal of misunderstanding in the wake of a study conducted at the University of Heidelberg, where a researcher reported increased levels of antimony in bottled water stored in PET containers.
The researcher acknowledged that the antimony levels in all of the PET bottled water he tested were far below the limits set by regulatory agencies around the world. In short, he did not find toxic levels of antimony in PET bottled water. In fact, the highest amount he found (in water that had been stored in PET for 3 months) was approximately 1/10 of the EPA’s allowable level of antimony in drinking water and 1/30 of the level set by the World Health Organization.
It is also important to note that the researcher reported results in parts per trillion, whereas conventional units for exposure limits for food contact materials are parts per billion (μg/liter) or ppm (mg/liter). Although numbers can be correctly expressed in various units, numbers expressed in different units must be compared carefully to avoid misunderstandings and misrepresentations.