Bisphenol A (BPA)
Questions and Answers about Bisphenol A
Radio MD Interview
with Dr. Birnbaum: BPA
January 28, 2013
Linda S. Birnbaum, Ph.D., Director of the National Institute of Environmental Health Sciences and the National Toxicology Program, discusses the latest research on bisphenol a (BPA).
What is bisphenol A?
Bisphenol A (BPA) is a chemical produced in large quantities for use primarily in the production of polycarbonate plastics and epoxy resins.
Where is BPA found?
Polycarbonate plastics have many applications including use in some food and drink packaging, e.g., water and infant bottles, compact discs, impact-resistant safety equipment, and medical devices. Epoxy resins are used as lacquers to coat metal products such as food cans, bottle tops, and water supply pipes. Some dental sealants and composites may also contribute to BPA exposure.
How does BPA get into the body?
The primary source of exposure to BPA for most people is through the diet. While air, dust, and water are other possible sources of exposure, BPA in food and beverages accounts for the majority of daily human exposure.
Bisphenol A can leach into food from the protective internal epoxy resin coatings of canned foods and from consumer products such as polycarbonate tableware, food storage containers, water bottles, and baby bottles. The degree to which BPA leaches from polycarbonate bottles into liquid may depend more on the temperature of the liquid or bottle, than the age of the container. BPA can also be found in breast milk.
Why are people concerned about BPA?
One reason people may be concerned about BPA is because human exposure to BPA is widespread. The 2003-2004 National Health and Nutrition Examination Survey (NHANES III) conducted by the Centers for Disease Control and Prevention (CDC) found detectable levels of BPA in 93% of 2517 urine samples from people six years and older. The CDC NHANES data are considered representative of exposures in the United States. Another reason for concern, especially for parents, may be because some animal studies report effects in fetuses and newborns exposed to BPA.
If I am concerned, what can I do to prevent exposure to BPA?
Some animal studies suggest that infants and children may be the most vulnerable to the effects of BPA. Parents and caregivers, can make the personal choice to reduce exposures of their infants and children to BPA:
- Don’t microwave polycarbonate plastic food containers. Polycarbonate is strong and durable, but over time it may break down from over use at high temperatures.
- Plastic containers have recycle codes on the bottom. Some, but not all, plastics that are marked with recycle codes 3 or 7 may be made with BPA.
- Reduce your use of canned foods.
- When possible, opt for glass, porcelain or stainless steel containers, particularly for hot food or liquids.
- Use baby bottles that are BPA free.
Where can I go for more information?
For more information on what other federal agencies are doing related to BPA, visit the following websites and search for “bisphenol A.”
How is NIEHS/NTP Researching the Health Effects of BPA
The National Institute of Environmental Health Sciences (NIEHS) and National Toxicology Program (NTP) have developed an integrated, multipronged, consortium-based approach to optimize BPA-focused research investments to more effectively address data gaps and inform decision making.
NIEHS/NTP BPA research investments made over the past four years include extramural research grants, establishment of a BPA Grantee Consortium, intramural research activities on BPA's mechanisms of action, launch of two clinical studies and an occupational study, development of a round robin experiment to validate BPA measurements in human serum, and, in collaboration with the Food and Drug Administration (FDA), formation of a consortium to design and execute a chronic toxicity study of BPA in rats.
NIEHS's new consortium-based approach has led to more integrated, collaborative efforts and should improve our ability to resolve controversies over the potential human health effects of exposures to low levels of endocrine active agents.
Read more about this "Consortium-Based Science: The NIEHS's Multipronged, Collaborative Approach to Assessing the Health Effects of Bisphenol A" .
NIEHS Awards Recovery Act Funds to Address Bisphenol A Research Gaps
NIEHS invested approximately $30 million on BPA-related research. This includes existing grants, the Recovery Act grants and supplements, in-house research and National Toxicology Program (NTP) projects. The NTP effort is part of a larger five-year commitment to collaborate with the U.S. Food and Drug Administration’s National Center for Toxicological Research to examine long-term health outcomes resulting from developmental exposures.
Researchers studying the health effects of the chemical bisphenol A (BPA) gathered in North Carolina in 2009 to launch an integrated research initiative to produce data that will allow for a comprehensive assessment of its possible human health effects.
Researchers who received funds from the American Recovery and Reinvestment Act to study BPA were brought together to meet with scientists from academia and government already working on the compound. The meeting was held Oct. 6, 2009 at the National Institute of Environmental Health Sciences (NIEHS).
Why did NIEHS use Recovery funds to support BPA research?
There is much uncertainty regarding the chemical BPA. BPA is used in certain food contact materials and was first approved by the FDA in the early 1960s. While recent assessments by authorities in the United States, Canada, Europe, and Japan agree that current food contact uses of BPA are safe, these assessments have identified the need to address data gaps. NIEHS wants to fill many of the research gaps in this area so informed personal and public health decisions can be made. For these reasons, NIEHS prioritized BPA research as a Signature initiative in the grants program undertaken with stimulus funds from the American Recovery and Reinvestment Act (ARRA). Some of the disease endpoints that Recovery Act-funded researchers will be investigating include behavior, obesity, diabetes, reproductive disorders, development of prostate, breast and uterine cancer, asthma, cardiovascular diseases and transgenerational or epigenetic effects.
What impact will the Recovery funding focused on BPA have?
The Recovery Act money will support the development of new data in a limited number of strategic areas where there is very little data. It will also help stimulate the replication and expansion of published studies that have been deemed by NTP/CERHR to have specific deficiencies. The goal of these ARRA funded grants is to produce both the animal and human data necessary to allow for a comprehensive assessment of the human health effects of BPA. Collectively, the results of these new ARRA funded studies and ongoing studies should begin to chip away at the uncertainties and research gaps and provide a better perspective of the potential threat that exposure to bisphenol A poses to public health.
National Toxicology Program Conclusions
What did the NTP conclude?
The NTP reached the following conclusions on the possible effects of current exposures to bisphenol A on human development and reproduction. Note that the possible levels of concern, from lowest to highest, are negligible concern, minimal concern, some concern, concern, and serious concern.
The NTP has some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to bisphenol A.
The NTP has minimal concern for effects on the mammary gland and an earlier age for puberty for females in fetuses, infants, and children at current human exposures to bisphenol A.
The NTP has negligible concern that exposure of pregnant women to bisphenol A will result in fetal or neonatal mortality, birth defects, or reduced birth weight and growth in their offspring.
The NTP has negligible concern that exposure to bisphenol A will cause reproductive effects in non-occupationally exposed adults and minimal concern for workers exposed to higher levels in occupational settings.
Read the report: The National Toxicology Program (NTP) Brief On Bisphenol A (BPA) .
Listen to NTP Speak on BPA
Mike Shelby, Ph.D.
NTP Senior Health Scientist