Bisphenol A (BPA)

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This article was contributed by the Pacific Northwest Pollution Prevention Resource Center

Overview

Bisphenol A (BPA) is an organic chemical used mainly for the production of plastics and other polymeric materials. According to the United States Environmental Protection Agency (EPA), approximately three-quarters of all BPA is used for the manufacture of polycarbonate, a clear, strong and shatter-resistant plastic (1). The other main use of BPA is as a component in epoxy resins and related materials. Epoxy resins have wide application for molded parts, including automobile panels and electronic components, but also for coatings and barrier materials used in water pipe, food can linings and metal jar lids, among other products.

Environmental Impact

Occurrence of BPA

BPA-containing materials are ubiquitous in any modern economy. The EPA estimates that in the US alone, releases of BPA to the environment exceed one-million pounds per year (1). Sources of human exposure include food, especially canned food, where BPA can leach from can lining materials, and thermal paper, where BPA-containing coating materials easily break off and contaminate fingers (2).

The disposal and recycle of BPA-containing materials also lead to new pathways of environmental exposure. For example, while thermal paper is a small fraction of all paper production and less than one-percent of industrial BPA use, it is believed to a major source of BPA emitted to surface waters (3). BPA is released from thermal paper coatings during the recycling of mixed papers. Some BPA remains in the fiber that will be re-used and enters “new” paper products, such as containerboard packaging, carton board, and paper towels. All of these products are potential food-contact materials.

BPA also ends up in aqueous recycling and paper mill effluents (3). While effluents are typically treated, some of the original BPA remains and is discharged to the environment. BPA emissions from domestic waste and landfill leachates also find their way into the ecosystem. While BPA breaks down fairly quickly in the environment, the nearly continuous release in some locations leads to steady, exposures to aquatic life. A number of studies have shown that BPA can affect reproduction, growth and development in these species and exposures during critical windows of development can have life-long consequences (4).

Controversy over Low-exposures to BPA and Endocrine Disruption

The occurrence of BPA in the environment and in humans and animals is not in dispute, but a vigorous debate has developed regarding the risk posed by typical low-level exposures to BPA. BPA is one of a number of synthetic chemicals known to mimic the effects of the human hormones, often called endocrine-disrupting chemicals (EDCs). EDCs can interfere with normal hormonal processes in the body. Given BPA’s wide use, the effect of bans or restrictions on BPA use would be wide-ranging on chemical manufacturers and food processors. The safety assessment process has been plagued by controversies over study design, inter-species differences in metabolism and mechanism, and dosing procedures, among other questions (5).

Chemical and plastic industry groups, such as the American Chemistry Council and PlasticsEurope suggest that for typical plastic and epoxy product applications, exposures to BPA are well within safe limits (c.f. BisphenolA.org) (6; 7), bpa.org]. While there is no authoritative US body on endocrine disruption, a recent scientific statement from the Endocrine Society suggests applying the precautionary principle, i.e., there is sufficient reason to suspect harm and measures should be taken to avoid BPA exposure (8). A report by the National Toxicology Program (organizationally part of the National Institutes of Health) states that they “…[have] some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to bisphenol A” (9). Risks were otherwise considered negligible for adults (except for occupational exposures).

Best Practices

Given the disagreement on the risks of BPA exposure, recommendations regarding use of BPA vary broadly. Nonetheless, major manufacturers have voluntarily withdrawn the use of polycarbonate for baby bottles, and major retailers have stopped carrying some polycarbonate products (10; 11).

A great deal of new data concerning BPA safety is likely to become available over the next months and years. In the meanwhile, for those concerned about the safety of BPA, there are many options to reduce exposure (12; 13):

Bottles/cups/utensils – avoid the use of food and beverage contact items manufactured from polycarbonate. Polycarbonate items often have a stamp with the symbol “PC” or recycling number 7. Be advised that number 7 is a catch-all category that also includes BPA-free plastics.
Food cans – some manufacturers have switched to the use of non-BPA containing can linings. Using frozen in place of canned vegetables should also reduce BPA exposure.
Thermal paper – Opt for no receipt in everyday ATM transactions; place credit card and other thermal paper receipts in envelopes separated from cash and other purse or pocket items. Wash your hands after handling receipts and keep receipts away from children.
Dental sealants/appliances – ask your dentist about BPA-free materials for dental sealants, filling materials and custom dental appliances (14).

Policy/Regulation

Federal

The United States Food & Drug Administration (FDA) regulates foods and food additives, which include food contact materials such as can-linings. Currently, BPA is approved for use in food contact materials, however, in a January 2010 update on BPA, the FDA described a variety of efforts to address concerns regarding BPA safety, including in-depth studies to clarify risk from BPA exposure, support for industry actions to eliminate BPA in bottles and infant feeding products, and support for the development of alternatives to BPA in can-linings (15).

In March 2010, the EPA announced a new chemical action plan for BPA. Under the plan, the EPA is evaluating possible rulemaking under the Toxic Substances Control Act to address the potential harm from exposure of BPA to aquatic species. Details on the proposed rulemaking are expected in autumn 2010. The EPA has also initiated a collaborative assessment of alternatives to BPA in thermal paper through its Design for Environment program. Results are expected in 2011 (16).

State and Municipal efforts to limit products containing BPA

Connecticut, Maryland, Minnesota, New York, Vermont, Washington and Wisconsin have passed measures to ban or limit BPA in food and drink containers with most of these measures targeting products aimed at infants or young children. Similar measures have been passed by some county and city governments across the United States (17). Some of these measures passed only after initially failing in earlier attempts at regulation, and of course, the majority of states and municipalities have left this matter to federal regulators. In 2009, California’s Proposition 65 Developmental and Reproductive Toxicant Identification Committee declined to identify BPA as a reproductive toxicant, but the issue is under continued study by the Office of Environmental Health Hazard Assessment (18).

International Regulatory Activity

A similar diversity of opinion on BPA safety exists internationally. Canada banned polycarbonate baby bottles in 2008 and is reportedly set to designate BPA as toxic. Denmark and France have banned the use of BPA in food and beverage containers for infants. Sweden is considering a similar ban following repeated delays in the release of the latest European Food Safety Agency’s (EFSA) safety assessment for BPA (BPA-containing materials are currently permitted by European Union regulation). In contrast, the Federal Institute for Risk Assessment (an agency of the Federal Republic of Germany) and Austria’s Agency for Health and Food Safety both consider polycarbonate products safe for children.