What does BPA research tell us?
What does BPA research tell us?
Bisphenol A (BPA) is one of the most thoroughly tested chemicals in commerce today. Because of its critical role in food contact and other plastic applications, expert panels, academic scientists and multiple government regulatory agencies have extensively studied and reviewed available research on the safety of BPA. The consensus of major government agencies around the world is that BPA is safe as used in its current applications. More information on BPA research can be found below.
Current BPA research can be separated into the following categories:
1. Government Safety Assessments
2. Independent Safety Assessments
3. Significant Laboratory Studies
1. Government Safety Assessments
- Department of Health and Human Services (HHS) and FDA: In the past few years, the FDA has made a concerted effort to review new research on BPA to provide evidence-based recommendations to the public. These recommendations include:“FDA’s Current Perspective on BPA” in 2013: FDA released an updated perspective on BPA, stating that “BPA is safe at the very low levels that occur in some foods.” This perspective is based on review by FDA scientists of hundreds of studies, including the latest findings from new studies conducted by the agency’s National Center for Toxicological Research (NCTR).
"Update on Bisphenol A for Use in Food Contact Applications" in 2010: HHS and the FDA released its recommendation to the public, which said that BPA "is not proven to harm children or adults…" This was consistent with a draft assessment issued by FDA in 2008 (see below). The update confirmed that studies using standardized toxicity tests continued to support the safety of BPA. FDA noted some studies, using novel approaches to testing for subtle effects, did raise questions and the agency would conduct additional scientific research to answer these key questions and clarify uncertainties. Although the agency noted "some concern," meaning additional research is needed, it did not take regulatory action or impose restrictions on the use of BPA. To read the full report, please click here.
"Draft Assessment of Bisphenol A for Use in Food Contact Applications" in 2008: The FDA released a draft report on BPA in food-contact products such as water bottles, food containers and baby bottles. The FDA stated the following: "FDA concludes that an adequate margin of safety exists for BPA at current levels of exposure from food contact uses, for infants and adults." More simply, this statement found that BPA is safe in food contact products. Please click here for the full report.
- Health Canada's current fact sheet on BPA states that "The current research tells us the general public need not be concerned. In general, most Canadians are exposed to very low levels of bisphenol A, therefore, it does not pose a health risk." To read the full fact sheet, please click here.
In October 2008, Health Canada released the results of its human health screening assessment on BPA. In its comprehensive assessment, Health Canada specifically reviewed a small number of studies that demonstrated neurobehavioral effects following oral administration of BPA in mice. In regard to these studies, Environment Canada concluded that "While collectively these studies provide evidence that exposure to bisphenol A during gestation and early postnatal life may be affecting neural development and some aspects of behaviour in rodents, the overall weight of evidence was considered limited from the perspective of rigour (e.g., study design limitations such as conduct of behavioural assessments at a single time point); power (e.g., limited number of animals per test group), corroboration/consistency (limited consistency of studies) and biological plausibility (e.g., certain studies involve use of a single dose, lack of dose response relationship). These limitations make it difficult to determine actual significance of findings to human health risk assessment." To read the full report, please click here.
- European Food Safety Authority (EFSA): The European Food Safety Authority (EFSA) recently announced a December 2011 opinion re-confirming the existing safe intake level for BPA. This recent opinion was driven by a report issued by France's Agency for Food Health Safety (ANSES) that claimed that minimal doses of BPA may have negative health effects on laboratory animals as well as on humans. Based on its findings, ANSES called for the substitution of BPA in certain applications. However, EFSA's review of the ANSES report found that it was limited to hazard identification only, while EFSA's previous 2010 review, which critically analyzed more than 800 recent studies with relevant scientific information on BPA, provided a full assessment of risk from human dietary exposure to BPA. For the majority of possible health effects, the EFSA Panel stated that there is no new information in the recent literature that would change its views as expressed in its 2010 opinion, and therefore determined that "the information in the ANSES report does not change the views of the Panel expressed in the 2010 opinion." This opinion re-confirmed the Tolerable Daily Intake for BPA of 0.05 mg/kg body weight set by EFSA in its 2010, 2008 and 2006 opinions, and is consistent with the findings of independent food safety authorities across the world, including Germany, the UK, Ireland, Switzerland, the Netherlands, Spain, the US and Australia and New Zealand.
In an assessment released on September 30, 2010, EFSA's panel of expert scientists critically analyzed more than 800 recent studies with relevant scientific information on BPA, including numerous studies that examined low doses of BPA. EFSA also consulted with national experts from across Europe, as well as several international risk assessment authorities, including FDA and Health Canada. The Panel concluded that "they could not identify any new evidence which would lead them to revise the current Tolerable Daily Intake for BPA of 0.05 mg/kg body weight set by EFSA in its 2006 opinion and re-confirmed in its 2008 opinion."
- Germany's Federal Institute for Risk Assessment (BfR): In July 2010, Germany's Federal Institute for Risk Assessment (BfR) released a detailed review of two recent BPA studies and concluded: "The results of the two studies do not substantiate the concerns for a specific toxic potential of bisphenol A adverse to neurological and behavioural development." For the full report, please click here.
Regarding Ryan et al. (2009), BfR concluded: "The results revealed no adverse effects in the low-dose range on behaviour and the development of female rat offspring whose dams were treated with bisphenol A during gestation and lactation.
Regarding Stump et al. (2010), BfR concluded: "The results obtained with these testing conditions did not provide any indications of adverse effects on neurological and behavioural development in the offspring. The study comprised also testing of very low dosages. Dietary administration of bisphenol A did not reveal indications for so-called 'low-dose effects.'"
- Food Standards Australia New Zealand (FSANZ): In November 2010, FSANZ updated their "Bisphenol A (BPA) and food packaging" fact sheet, which stated, "Bisphenol A does not cause cancer. BPA belongs to a group of substances that can act in a similar way to some hormones and, as such, are sometimes called 'endocrine disruptors.' Some studies in laboratory animals suggest that low levels of (consumed) BPA may have an effect on the reproductive system while other studies indicate no effect. Similar consequences in consumers at these low concentrations are considered unlikely because BPA is rapidly inactivated and then excreted in the urine in humans." To find out more, please click here.
2. Independent Safety Assessments
- Advisory Committee of the German Society for Toxicology (2011), "Critical evaluation of key evidence on the human health hazards of exposure to bisphenol A": In April 2011, Critical Reviews in Toxicology released a review on BPA conducted by the Advisory Committee, which concluded, "BPA exposure represents no noteworthy risk to the health of the human population, including newborns and babies." Furthermore, it found, "To date, more than 5,000 studies on BPA have been published. It is obvious that this should be enough information to resolve the controversy, but nevertheless this has not yet been achieved and those not directly involved in BPA research are usually puzzled by the never-ending and sometimes emotional debate." After reviewing all available evidence and controversial arguments, the Committee concluded that the "current Tolerable Daily Intake (TDI) level for BPA is adequately justified." In its specific evaluation of studies reporting that low doses of BPA cause adverse health effects in laboratory animals, the Committee found that these studies "failed to meet minimal quality criteria for experimental design and statistical analysis" and that their results were inconsistent with more robust studies on similar endpoints. A full report can be found here.
- World Health Organization (WHO): In November 2010, an international panel of more than 30 experts organized by the WHO released a report summarizing their views on BPA after reviewing the latest scientific evidence. Based on the expert report, WHO stated that the circulating levels of BPA in the human body are very low, indicating that "BPA is not accumulated in the body and is rapidly eliminated through urine." Furthermore, in regard to recent studies claiming associations between BPA and adverse health outcomes, it noted, "It is difficult to interpret the relevance of these studies in the light of current knowledge of this compound. Until these associations can be confirmed, initiation of public health measures would be premature." To read the full report, please click here.
- Health Canada: On August 26, 2010, Health Canada released a new report that reviewed the amount of BPA found in canned beverages. According to Health Canada, the report, "further confirm[s] that exposure to BPA from canned beverage products is very low and poses no health or safety concerns to the general population." To read the full report, please click here.
In a June 2010 review on BPA in canned food products, Health Canada examined BPA levels in 78 canned food products. Health Canada concluded that "The results of this survey confirm that exposure to BPA from canned food products is very low and poses no health or safety concerns to the general population." To read the summary of this Health Canada study, please click here.
In its August 2008 BPA Health Risk Assessment, Health Canada reviewed current data to assess the potential for health risks arising from dietary sources of BPA. Health Canada concluded that, "Based on the overall weight of evidence, Health Canada's Food Directorate has concluded that the current dietary exposure to BPA through food packaging uses is not expected to pose a health risk to the general population, including newborns and young children. This conclusion has been re-affirmed by health agencies in other countries, including notably the United States, the European Union and Japan." To read the full report, please click here.
In addition to the studies, reviews and assessments noted above, Health Canada has conducted multiple other scientific assessments on BPA. For additional information or to read the results of these assessments, please click here.
- In October 2008, an expert scientific panel, convened by Gradient Corporation, published the results of its weight-of-the-evidence evaluation of low-dose reproductive and developmental effects of BPA. Based on its review of scientific literature available through July 2008, the panel concluded: "The weight of evidence does not support the hypothesis that low oral doses of BPA adversely affect human reproductive and developmental health." This evaluation is the third in a series that began with an evaluation, published in 2004, by an independent panel of scientific experts organized by the Harvard Center for Risk Analysis. To view a summary, please click here. To view the full report, please click here.
3. Significant Laboratory Studies:
- Ning et al. (2011), "Relationship of Urinary Bisphenol A Concentration to Risk for Prevalent Type 2 Diabetes in Chinese Adults": In a 2011 study conducted by doctors at the Shanghai Institute of Endocrine and Metabolic Diseases and published in the Annals of Internal Medicine, researchers examined the association between BPA exposure and type 2 diabetes in 3,423 Shanghai residents aged 40 years or older. Study data indicated that there was no clear association between BPA levels and type 2 diabetes, and did not replicate findings from a previous study that claimed a link between BPA exposure and diabetes.
- Teeguarden et al. (2011), "24-Hour Human Urine and Serum Profiles of Bisphenol A During High Dietary Exposure": This EPA-funded study, conducted by scientists at the Pacific Northwest National Laboratory, FDA and CDC, assessed blood and urine concentrations of BPA in healthy adults who had consumed a controlled diet including high levels of canned foods likely to be significant sources of BPA. Consistent with previous human and animal studies, the results of this study confirmed that BPA is efficiently converted to a biologically inactive metabolite and rapidly excreted in urine. Illustrating the efficiency of this metabolic process, no un-metabolized BPA was detected in the bloodstream of any participant at any time point in the study even with the atypically high BPA exposure levels and a sensitive analytical method. Only the inactive metabolite of BPA was transiently found at low levels before it was eliminated from the body. Importantly, results indicated that, because of the efficient way BPA is processed in the body, it is very unlikely that BPA could cause health effects as the estimated maximum levels of BPA in blood in this study are 1 to 3 orders of magnitude below levels that have been linked to potentially adverse effects in the most sensitive of animal tests. For more information, please click here.
- Rudel et al. (2011), "Food Packaging and Bisphenol A and Bis (2-Ethyhexyl) Phthalate Exposure: Findings from a Dietary Intervention": On March 30, 2011, Environmental Health Perspectives (EHP) released this study, which demonstrates once again that typical exposure to BPA remains very low. In this study of 5 families, the 20 participants participated in a "fresh foods" dietary intervention. Levels of BPA metabolites in participants' urine were measured prior to, during and after the dietary interventions. All the measurements confirmed that the BPA levels were more than 1,000 times below the government-established safe intake level. The levels of BPA measured in this study were consistent with levels found in the Centers for Disease Control and Prevention (CDC) 2005-2006 NHANES, which provided large-scale evidence that BPA exposure levels in the U.S. are very low. This study also reaffirmed that humans metabolize BPA very quickly, demonstrating that BPA does not build up in the body, but is quickly eliminated. For the full report, please click here.
- Stump et al. (2010), "Developmental Neurotoxicity Study of Dietary Bisphenol A in Sprague-Dawley Rats": The objective of this study, conducted in Sprague-Dawley rats, was to determine the potential of BPA to induce functional and/or morphological effects to the nervous system of offspring following dietary exposure of the mother during pregnancy and lactation. In this study, pregnant female rats were exposed to BPA via the diet at dosage levels that spanned the range from low doses, as used in some published studies reporting developmental neurotoxicity, to a high dose that was anticipated to result in systemic toxicity in the pregnant rat (0, 0.01, 0.1, 5, 50, and 150 mg/kg/day). The offspring, exposed to BPA in utero, via milk while nursing and through the diet once they started to feed, were studied for functional or morphological effects on their nervous systems. The study concluded that there were no neurologic or neurobehavioral effects at any dose tested. Please click here to learn more about the study.
- Doerge et al. (2010), "Pharmacokinetics of bisphenol A in neonatal and adult Sprague-Dawley rats": This study concluded that BPA is efficiently metabolized by adult rats after oral exposure and, while neonatal rats are not identical to adults, they also have the capability to efficiently metabolize BPA. As a result of efficient metabolism, estrogenic effects from BPA are unlikely due to the very low levels of unmetabolized BPA in the body after oral exposure. Because BPA is efficiently metabolized after oral exposure, studies that expose animals by subcutaneous injection are of limited relevance to human health concerns that primarily involve oral exposure. Because of efficient metabolism and rapid elimination, BPA does not accumulate in the body. For more information, click here.
- Doerge et al. (2010), "Pharmacokinetics of bisphenol A in neonatal and adult rhesus monkeys": This study on the pharmacokinetics of BPA in monkeys, is conceptually similar to the study on rats mentioned above by Doerge et al. (2010), but of more significance since monkeys are biologically closer to humans. The study found, "These observations imply that any toxicological effect observed in rats from early postnatal exposures to BPA could over-predict those possible in primates of the same age, based on significantly higher internal exposures and overall immaturity at birth." Please click here for more information.
- LaKind and Naiman (2010),"Daily Intake of Bisphenol A (BPA) and Potential Sources of Exposure -- 2005-2006 National Health and Nutrition Examination Survey (NHANES)": This study demonstrates once again that the average American's exposure to BPA remains extraordinarily low. Results indicate that median daily intake of BPA is 34 nanograms per kilogram of body weight for the overall population. Additionally, while it was found that children are exposed to slightly higher levels of BPA than adults, these levels are still almost 1,000 times below recommended safe exposure limits. This study provides further evidence that BPA exposure levels in the U.S. are low in both adults and children, and government bodies around the world have concluded that these levels of exposure do not pose a risk to human health at any age. For more information, please click here.
- Statistics Canada (2010), "Bisphenol A concentrations in the Canadian population, 2007 to 2009": On August 16, 2010, Statistics Canada released biomonitoring data, which included data on BPA. The 2007 to 2009 Canadian Health Measures Survey (CHMS) is the first national survey to measure bisphenol A (BPA) in Canadians. The study found that metabolites of BPA were detected in the urine of 91% of the population aged six to 79 years. This data demonstrated that the typical levels of BPA found in the general Canadian population are extremely low -- approximately 1,000 times below the safe intake level for BPA set by Health Canada for all age groups, including children and teenagers. To read the Statistics Canada report, please click here.
- Ryan et al. (2010), "In Utero and Lactational Exposure to Bisphenol A, In Contrast to Ethinyl Estradiol, Does Not Alter Sexually Dimorphic Behavior, Puberty, Fertility, and Anatomy of Female LE Rats": In this study, funded and conducted by the Environmental Protection Agency (EPA), female rats were fed BPA during pregnancy and lactation at dosage levels approximately 40 to 4,000 times above estimated median human consumption, and the female offspring were studied for effects on behavior and reproductive function. No effects from exposure to BPA were found in this study. In contrast, the well-known estrogen ethinyl estradiol (EE2) had significant effect on the rodents, demonstrating the sensitivity of the study and the validity of the results for BPA. For more information, please click here.
- Tyl (2009), "Basic Exploratory Research versus Guideline-Compliant Studies Used for Hazard Evaluation and Risk Assessment: Bisphenol A as a Case Study": Click here to learn more about this study.
- Tyl et al. (2008), "Two-Generation Reproductive Toxicity Study of Dietary Bisphenol A in CD-1 (Swiss) Mice": Click here to learn more about the study.
- Howdeshell et al. (2007), "Gestational and Lactational Exposure to Ethinyl Estradiol, but not Bisphenol A, Decreases Androgen-Dependent Reproductive Organ Weights and Epididymal Sperm Abundance in the Male Long Evans Hooded Rat": Click here to learn more about this study.