Questions and Answers about the National Toxicology Program's Evaluation of Bisphenol A
Listen to NTP Speak on BPA
Read the full transcripts (http://www.niehs.nih.gov/news/media/questions/ntp-speaks-bpa.cfm).
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:.
What does “some concern” mean?
“Some concern” represents the mid-point of a five-level scale of concern used by the NTP. The levels from highest to lowest are:
In the case of BPA, the NTP and our expert panel expressed “some concern” for potential exposures to the fetus, infants and children. There are insufficient data from studies in humans to reach a conclusion on reproductive or developmental hazards presented by current exposures to bisphenol A, but there is limited evidence of developmental changes occurring in some animal studies at doses that are experienced by humans. It is uncertain if similar changes would occur in humans, but the possibility of adverse health effects cannot be dismissed.
The NTP and expert panel conclusions are based on the weight of scientific evidence and integrate toxicity and exposure information. Conclusions are presented in narrative form and present the best scientific judgment on the likelihood that adverse reproductive and/or developmental effects may occur under the exposure circumstances specified, i.e., a qualitative statement of potential risk. The likelihood of an adverse effect resulting from human exposure is expressed as a level of concern.
The NTP or an expert panel convened by the NTP may express "serious concern" if a substance is found to cause reproductive or developmental effects in humans or if human exposures are similar to doses that clearly cause adverse developmental or reproductive effects in laboratory animals.
At the opposite extreme, a conclusion of "negligible concern" may be warranted when the available data provide good evidence that the substance under evaluation is not a reproductive or developmental toxicant or human exposures are very low compared to dose levels that cause adverse effects in laboratory animals.
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:
NTP and Bisphenol A
What is NTP?
The National Toxicology Program (NTP) is an interagency program of the Department of Health and Human Services established in 1978. The program was created as a cooperative effort to coordinate toxicology testing programs within the federal government, strengthen the science base in toxicology, develop and validate improved testing methods, and provide information about potentially toxic chemicals to health, regulatory, and research agencies, scientific and medical communities, and the public. The NTP is headquartered at the NIEHS.
For more information about the NTP, visit the NTP Web site (http://ntp.niehs.nih.gov).
Why is BPA of interest to the NTP?
Bisphenol A was selected for evaluation by the NTP because of the following factors:
What role does the NTP play in FDA safety assessments?
The FDA often uses data and information from the NTP to make safety evaluations of FDA products. Unlike the FDA, the NTP is not a regulatory body. In the case of BPA, the NTP Center for the Evaluation of Risks to Human Reproduction evaluated the available scientific literature on BPA to serve as an environmental health resource for the public, regulatory, health and research agencies about the potential for exposure to BPA to cause adverse reproductive or developmental effects in people.
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.”
The Evaluation Process
What is an NTP Brief?
The National Toxicology Program Brief on Bisphenol A (BPA) includes the NTP’s conclusions on the reproductive and developmental hazards associated with exposure to BPA. The NTP Brief is based on the report completed in Fall 2007 by an expert panel on BPA convened by the NTP Center for the Evaluation of Risks to Human Reproduction (CERHR), public comments received on the report, peer review comments, and new relevant scientific literature.
The NTP Brief on Bisphenol A is not a quantitative risk assessment, nor is it intended to supersede risk assessments conducted by regulatory agencies. The NTP Brief on Bisphenol A is intended to serve as an environmental health resource for the public, as well as regulatory and health agencies.
The scientific literature on BPA is complex and rapidly expanding. The goal of the NTP Brief on Bisphenol A is to present a balanced evaluation of this literature and identify potential health concerns related to reproduction and development, as well as to present areas of scientific uncertainty. This information may be useful to regulatory agencies as they initiate or revise their risk assessments.
Was the NTP Brief on BPA peer-reviewed?
Yes, on June 11, 2008 the NTP Board of Scientific Counselors (BSC), supplemented with ad hoc experts, met in Research Triangle Park, NC during a public meeting to peer review the Draft NTP Brief on Bisphenol A.
Following an in-depth discussion of the evidence including public comments, the BSC agreed with the overall conclusions in the Draft Brief including “some concern” for neural and behavioral effects and effects on the prostate gland in fetuses, infants, and children at current human exposures to BPA. More information about the http://ntp.niehs.nih.gov/go/32917 (http://ntp.niehs.nih.gov/go/32917).. Also, the presentations from the meeting are available on the website at
What is an NTP-CERHR Monograph?
The results of the BPA evaluation will be published in the NTP-CERHR Monograph. The monograph is a collection of information on a particular chemical that includes the NTP Brief and the Expert Panel Report. NTP-CERHR Monographs are made publicly available and transmitted to appropriate health and regulatory agencies.
What happens once the NTP-CERHR Monograph becomes available?
We share the results widely. The NTP-CERHR Monograph will be added to the NTP/CERHR and the NIEHS web sites, and distributed to federal and state agencies and interested individuals and organizations. It is also indexed in PubMed. The NTP will share the Monograph broadly to ensure that the public, as well as government health, regulatory, and research agencies have the information to use when acting on public health issues. The NTP has no regulatory authority.
When and why was the NTP CERHR established?
The National Toxicology Program (NTP) and the National Institute of Environmental Health Sciences (NIEHS) established the NTP Center for the Evaluation of Risks to Human Reproduction (CERHR) in 1998. CERHR is an environmental health resource for the public, as well as regulatory and health agencies. CERHR provides accessible, scientifically-based, uniform assessments of the potential adverse effects on human reproduction and development resulting from chemical and other exposures.
What role did the CERHR Expert Panel play?
In 2007, the CERHR convened a 12-member, independent panel of government and non-government scientists to evaluate the scientific studies on the potential reproductive and developmental hazards of BPA. The expert panel met publicly on March 5-7, 2007 and August 6-8, 2007. The final CERHR Expert Panel report was released in November 2007 and is available at.
Who served on the CERHR BPA Expert Panel?