US Food and Drug Administration (FDA) Reaffirms Safety of Food-Contact Products Containing Bisphenol A (BPA)
August 20, 2008
On August 15, 2008 the US Food and Drug Administration (FDA) released a draft assessment of the safety of bisphenol A in food-contact products such as baby bottles, water bottles and food containers. The assessment, which was conducted by a cross-agency task force of FDA scientists that is reviewing the safety of bisphenol A in all FDA-regulated products, reaffirms the safety of products made from polycarbonate plastic and epoxy resins, including products intended for use by infants and children.
The assessment took into account data and information from recent reviews of bisphenol A conducted by government bodies in the US, Canada and Europe, as well as from non-governmental sources and the scientific literature. Key studies and specific health effects identified in other reviews as being of some concern were independently analyzed by FDA scientists.
Overall, the assessment states: “FDA concludes that an adequate margin of safety exists for BPA at current levels of exposure from food contact uses, for infants and adults.” The findings of the draft FDA assessment are consistent with and further support the conclusions of many earlier evaluations that bisphenol A is not a risk to human health at the low levels to which people might be exposed.
Why Did FDA Assess the Safety of Bisphenol A?
The Food and Drug Administration (FDA) is the agency in the United States that is responsible for regulating products that contact food. Since bisphenol A is used primarily to make polycarbonate plastic and epoxy resins, both of which are used in food-contact products (e.g., baby bottles, water bottles, food containers), FDA has an interest in the safety of bisphenol A.
Although polycarbonate plastic and epoxy resins have been authorized by FDA for use in food-contact products for decades, a large amount of scientific information relevant to the safety of bisphenol A has been generated in recent years. This information has been reviewed recently by numerous scientific and government bodies around the world, including the US National Toxicology Program (NTP).(1) The NTP report provides scientific information to FDA, but by itself does not provide a complete safety assessment and NTP has no regulatory responsibility.
How Was the Safety Assessment Conducted?
With the availability of the NTP report, FDA formed a cross-agency Task Force(2) to conduct a complete safety assessment by FDA scientists and determine if continued use of bisphenol A in FDA-regulated products meets FDA’s safety standard:
“Safe or safety means that there is reasonable certainty in the minds of competent scientists that the substance is not harmful under the intended conditions of use.”(3)
In addition to data and information from the NTP report, FDA scientists also considered information from other recent reviews of bisphenol A and from the scientific literature. Included were reviews from government bodies (e.g., Health Canada, European Food Safety Authority, Norwegian Scientific Committee on Food Safety) as well as non-governmental sources (e.g., Environmental Working Group, the “Chapel Hill group”).
Starting with these sources of information, FDA scientists conducted their own independent analysis of key studies and specific health effects identified in other reviews as being of some concern (e.g., effects on the prostate and mammary glands, effects on puberty, neural and behavioral effects). The assessment focused in particular on infants and children.
What Were the Conclusions of the Assessment?
Overall, the assessment states: “FDA concludes that an adequate margin of safety exists for BPA at current levels of exposure from food contact uses, for infants and children.”(4)
To support this conclusion, FDA first updated their estimate of infant exposure to bisphenol A based on extensive new information, resulting in exposure estimates for infants less than 12 months of age ranging from 0.15 to 2.42 micrograms/kg-day. The estimated exposure for adults from FDA’s earlier analysis remained unchanged at 0.185 micrograms/kg-day. The values for infants and adults are considered by FDA to be conservative, meaning it is likely that actual exposures are lower than the estimated values.
Based on their review of many laboratory animal studies, FDA then established no-observed-adverse-effect-levels (NOAEL) for systemic (5 milligrams/kg-day), reproductive (50 milligrams/kg-day) and offspring (50 milligrams/kg-day) health effects.
Margins of safety (MOS) were calculated for each combination of a NOAEL and exposure level as a measure of safety. The lowest MOS values, which are the ratio of a NOAEL and an exposure value, were approximately 2,000 for infants and 27,000 for adults. These values indicate that exposure to bisphenol A is well below a level that could cause harm.
What Are the Next Steps?
The draft report will be peer-reviewed by a subcommittee of FDA’s Science Board at a public meeting on September 16, 2008.(5). A final draft of the report will then be reviewed by the full Science Board at their October 31, 2008 meeting. The final report along with recommendations will then be communicated to the FDA commissioner.
How Does FDA’s Assessment Compare with Other Recent Assessments?
In recent years, many scientific and government bodies around the world have examined the science supporting the safety of bisphenol A. The findings of the draft FDA assessment are consistent with and further support the conclusions of many earlier evaluations that bisphenol A is not a risk to human health at the low levels to which people might be exposed.
In addition to the FDA assessment, four other evaluations of bisphenol A with consistent conclusions have been completed in 2008:
- The European Food Safety Authority updated their evaluation of bisphenol A in July 2008, with a particular focus on infants and children.(6). The update confirmed the validity of their 2007 evaluation, including a Tolerable Daily Intake of 50 micrograms/kg-day.(7)
- An update to a European Union risk assessment, originally published in 2003, was published in April 2008 to comprehensively include new scientific information.(8)
- In February 2008, NSF International(9) published their evaluation(10) of bisphenol A to support derivation of a Reference Dose, which is equivalent to a TDI.
- A weight-of-the-evidence evaluation of low-dose reproductive and developmental effects of bisphenol A conducted by an expert scientific panel,(11),(12) updated again(13) to include the most recent scientific information, concluded: “The weight of evidence does not support the hypothesis that low oral doses of BPA adversely affect human reproductive and developmental toxicity.”
(3) The FDA safety standard is incorporated into regulation 21 CFR§170.3(i). The safety standard also states that complete certainty of absolute harmlessness is scientifically impossible to establish.
(9) NSF International (http://www.nsf.org) is an independent, not-for-profit, non-governmental organization that is the world leader in standards development, product certification, education, and risk-management for public health and safety.
(10) Willhite, C. C., Ball, G. L., and McLellan, C. J. 2008. Derivation of a bisphenol A oral reference dose (RfD) and drinking-water equivalent concentration. Journal of Toxicology and Environmental Health, Part B. 11(2):69-146. The complete paper is available at http://dx.doi.org/10.1080/10937400701724303.
(11) Goodman, J. E., McConnell, E. E., Sipes, I. G., Witorsch, R. J., Slayton, T. M., Yu, C. J., Lewis, A. S., and Rhomberg, L. R. 2006. An Updated Weight of the Evidence Evaluation of Reproductive and Developmental Effects of Low Doses of Bisphenol A. Critical Reviews in Toxicology. 36:387-457. For a summary of this study, see http://www.gradientcorp.com/coinfo/RiskBull.html.
(12) Gray, G. M., Cohen, J. T., Cunha, G., Hughes, C., McConnell, E. E., Rhomberg, L., Sipes, I. G., and Mattison, D. 2004. Weight of the evidence evaluation of low-dose reproductive and developmental effects of bisphenol A. Human and Ecological Risk Assessment. 10:875-921. For a description of this study and a link to the full paper, see http://www.bisphenol-a.org/whatsNew/20040903Harvard.html. For information on a new weight of evidence evaluation, see http://www.bisphenol-a.org/whatsNew/20060619.html.
(13) Goodman, J. E., Witorsch, R. J., McConnell, E. E., Sipes, I. G., Slayton, T. M., Yu, C. J., Franz, A. M., and Rhomberg, L. R. 2008. Weight-of-evidence evaluation of reproductive and developmental effects of low doses of bisphenol A. Critical Reviews in Toxicology. In Press.