We want to share some plastics facts about a current topic of concern in plastics health and safety. You may have heard about BPA, a chemical commonly found in some plastics. But what plastics? What is the risk? Is anyone doing anything to improve the situation? Over the next few posts we will address the facts on three facets of BPA in the plastics industry: Evidence of human health effects from BPA exposure, Environmental fate and transport of BPA, Industry responses and solutions to the problem with BPA and other hazardous chemicals.
We hope this answers your questions and dispels some of the myths!
The Safety of BPA in Polycarbonates and Epoxy Resins
Kyle Arsenault, UMass Lowell
The debate regarding the use of Bisphenol A has plagued consumer markets regarding the disputed safety of this chemical. Bisphenol A, commonly known as BPA, is the main constituent of polycarbonate plastics. Polycarbonate materials are used everywhere from CDs to food storage containers. In addition to its use in polycarbonate plastics, BPA is also found in epoxy resins which are used to make products such as paints, protective coatings, and metal food can linings. According to Chemical Market Associates Inc (CMAI), close to 2.8 million tons of BPA were produced in the year of 2002. Thomas Zincke is credited with the initial synthesis of BPA in 1905, when he combined phenol and acetone to create this useful compound. The synthesis of the chemical into plastic materials came in the year of 1953 by Dr. Hermann Schnell and Dr. Dan Fox. According to the American Chemical Society, BPA had useful properties, “in particular optical clarity, shatter-resistance, and high heat resistance.” As consumer needs grew and single-use disposable items became commonplace throughout the world, the use of BPA expanded exponentially. If you are interested in learning more about the history of BPA please click here.
It is important to note that BPA is an intrinsic part of the production of the polycarbonates and epoxies we use today. To eliminate its use, the industry will have to develop new materials altogether, not just find a “drop-in” replacement. The expansive use of BPA, particularly in food packaging, raises concerns regarding the safety of this chemical. According to a safety assessment made by the United States National Academy of Sciences in the year of 1983, “BPA from food contact with polycarbonate plastic and epoxy resin is minimal and poses no known risk to human health.” Animal tests revealed that BPA has a negative effect when 50 mg of BPA is consumed per kg of body weight per day, but the average daily consumption of BPA materials is only 0.000118 mg/kg. The United States Food and Drug Administration, the European Commission Scientific Committee on Food, the United Kingdom Food Standards Agency, and the Japanese Ministry for Health support these findings.
For polycarbonate materials such as sports safety equipment, medical devices, and food storage containers, the American Chemical Society estimates that BPA consumption is, “less than 5 parts per billion, under conditions typical for uses of polycarbonate products.” By these estimates, the Average American would have to ingest 600 kg (1300 lbs.) to exceed the daily limit of BPA consumption recommended by the environmental protection agency. Toxicology experiments conducted by the European Commission's Scientific Committee on Food (SCF), reveal that average consumption ranges from “0.0048 to 0.0016 milligrams per kilogram body weight per day, which is below the tolerable daily intake set by the SCF of 0.01 mg per kilogram body weight per day”
The findings regarding BPA in epoxy cans concluded similar results. Epoxy resin, used as an inner coating on metal food and beverage containers, protects these metal cans from corroding. The BPA additive in most epoxy resins is designed to last for a little over forty years, meaning that the material is extremely durable and does not degrade. According to a study conducted by the Society of Plastics Industry Inc in 1995, “the estimated dietary intake of BPA from can coatings is less than 0.00011 milligrams per kilogram per day. This level is 450 times lower than the maximum acceptable or reference dose for BPA of .05 milligrams per kilogram body weight per day, established by the U.S. Environmental Protection Agency.” As a coating used widely in food packaging in the United States, the European Union, and the United Kingdom, BPA continues to be observed as safe and non-toxic material in minimal amounts.
The health concerns of BPA are most accurately summarized using the low-dose hypothesis. According to the American Chemical Society, “health effects occur at doses far below levels previously determined to be safe using well-established toxicological procedures and principles. This hypothesis further asserts that health effects may only be observed at high doses while much lower doses result in no effects.” The volume of studies regarding the safety of BPA reveals its minimal threat to human health.
Though BPA has been found to be non-toxic in small dosages, many companies are making the move to remove BPA from their products, particularly products made specifically for babies and children. BPA-free products are a smart choice due to the greater potential for harm to children and babies, who have a smaller body weight than adults, commonly put things in their mouths, and are in a period of rapid biological and neurological development. Though BPA offers important material qualities, the BPA-free movement is growing throughout the world.
Please be on the lookout for the third blog post in this series that will address how consumer protection agencies continue to monitor hazardous materials and revise recommendations. The blog post will also discuss how scientists should continue researching alternatives while ensuring that the replacements are not potentially more harmful than existing materials.
American Chemical Society . “Plastics American Chemistry .” About BPA: Polycarbonate Plastic , plastics.americanchemistry.com/Product-Groups-and-Stats/PolycarbonateBPA-Global-Group/About-BPA-Polycarbonate-Plastic.pdf.
Bisphenol A . “Bisphenol A Human Safety.” Bisphenol A (BPA) Human Safety, www.bisphenol-a.org/about/bpa-info/bpa-humansafety.html.
“Bisphenol A Low-Dose Endocrine Hypothesis Not Confirmed.” BPA Low-Dose Endocrine Disruptor Hypothesis Not Confirmed - Bisphenol A, www.bisphenol-a.org/human/herLowDose.html.
Bisphenol A. “Polycarbonate Plastics and Bisphenol A Release .” Bisphenol A, www.bisphenol-a.org/human/polyplastics.html.
.Bisphenol-a. “SAFETY OF EPOXY CAN COATINGS.” BPA Infromation Sheet , www.bisphenol-a.org/pdf/Epoxy.pdf.