European Food Safety Authority (ESFA) Reaffirms Safety of Bisphenol A (BPA) in Food-Contact Products
July 30, 2008
The European Food Safety Authority (EFSA) has released an update that confirms the validity of their recent assessment of bisphenol A and reaffirms the safety of consumer products such as baby bottles, water bottles and food containers made from polycarbonate plastic and epoxy resins.
The update was conducted to more fully evaluate the capability of adults and infants to metabolize and eliminate bisphenol A. Based on review of the most recent information on the way that bisphenol A is processed in the body, EFSA concluded that infants and children have sufficient capacity to convert bisphenol A to the same biologically inactive metabolites that are efficiently formed in adults. Exposure of the fetus to bisphenol A would be negligible due to the maternal capacity to convert bisphenol A to the same metabolites.
Since people are exposed to bisphenol A at levels well below the Tolerable Daily Intake set by EFSA, these findings also reaffirm the conclusion that bisphenol A is not a risk to human health at the low levels to which people, including infants and children, might be exposed from use of consumer products. This conclusion is consistent with and supports several other evaluations of bisphenol A that have been completed this year.
Who is EFSA and What Did They Do?
The European Food Safety Authority (EFSA), established by the European Parliament in 2002, provides the European Commission, the European Parliament and the European Member States with a sound scientific basis for legislation and policies related to food safety. Included in the scope of EFSA’s work are assessments of the safety of food packaging and other materials that contact food.
On July 23, 2008, EFSA released an update(1) to a comprehensive safety assessment of bisphenol A that was published by EFSA in early 2007
.(2) Bisphenol A is a substance of interest to EFSA since it is primarily used to make polycarbonate plastic and epoxy resins, both of which are used in food contact products such as baby bottles, water bottles and food containers. The assessment was conducted by one of EFSA’s expert panels, consisting of independent scientific experts from across the European Union.
Why Did EFSA Update their Safety Assessment?
In its 2007 assessment, EFSA established a Tolerable Daily Intake (TDI)(3) for bisphenol A of 50 micrograms/kg bodyweight/day and concluded that people are exposed to bisphenol A at levels well below the TDI. This assessment strongly supports the safety of consumer products made from polycarbonate plastic and epoxy resins.
A key aspect of the earlier assessment is that there are significant differences between humans and rodents; specifically that people metabolize and excrete bisphenol A from the body far more quickly than do rodents. These differences further limit the relevance for human risk assessment of rodent studies that report health effects at low doses of bisphenol A.
Although it is well established that adults have the capability to efficiently metabolize and quickly excrete bisphenol A, the capability of the fetus and infants to process bisphenol A in the same way has been questioned by some scientists. The update to the EFSA assessment was specifically aimed at addressing these questions.
What Were the Findings of the Updated Assessment?
After review of the most recent information available on the way that bisphenol A and related substances are processed in the body, EFSA confirmed that their earlier safety assessment remains valid. In particular, the previously established TDI “provides a sufficient margin of safety for the protection of the consumer, including foetuses and newborns.”
Confirmation of the earlier assessment was supported by a number of key findings that address recent questions on the capability of the fetus and infants to metabolize bisphenol A:
- The human body rapidly metabolizes and eliminates bisphenol A from the body after exposure.
- Exposure of a human fetus to free bisphenol A would be negligible due to the maternal capacity to convert bisphenol A to biologically inactive metabolites.
- Infants and children have sufficient capacity to convert bisphenol A to the same metabolites as adults at doses below 1 milligram/kg bodyweight/day, which is 20-times higher than the TDI. As reported in the earlier EFSA assessment, exposure of infants and children to bisphenol A is well below the TDI, resulting in a large margin of safety.
- Although one recent study suggested that neonatal mice do not efficiently metabolize bisphenol A,(4) the EFSA expert panel found that no conclusions could be drawn from this study due to many study design limitations.
- Because of metabolic differences between humans and rodents, exposure to free bisphenol A in adult, fetal and neonatal rodents will be greater than in humans. As a result, rodents are more susceptible to bisphenol A induced toxic effects than humans.(5)
Overall, the assessment strongly reaffirms the conclusion that human exposure to trace levels of bisphenol A from use of consumer products is not a risk to human health, including the health of infants and children.
How Does the EFSA Assessment Compare with Other Recent Evaluations?
In recent years, many scientific and government bodies around the world have examined the scientific evidence supporting the safety of bisphenol A. The findings of the updated EFSA 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 updated EFSA assessment, three other evaluations of bisphenol A with consistent conclusions have been completed in 2008:
- A European Union risk assessment, dated April 2008, has been comprehensively updated to include new scientific information available since the original assessment was published in 2003.(6)
- In February 2008, NSF International(7) published their evaluation(8) 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,(9),(10) updated again(11) 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 Tolerable Daily Intake is defined as an estimate of the amount of a substance, expressed on a body weight basis, that can be ingested daily over a lifetime without appreciable risk.
(4) Taylor, J. A., Welshons, W. V., and vom Saal, F. S. 2008. No effect of route of exposure (oral; subcutaneous injection) on plasma bisphenol A throughout 24 hr after administration in neonatal female mice. Reproductive Toxicology. 25(2):169-176.
(5) As described in the updated EFSA assessment, bisphenol A is metabolized to bisphenol A-glucuronide along with smaller amounts of bisphenol A-sulfate, both of which have no known biological activity and have been shown to not be estrogenic. Unmetabolized (or free) bisphenol A, which is weakly estrogenic, is the biologically active form.
(7) 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
(8) 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.
(9) 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.
(10) 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.
(11) 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.