Toxicity, health effects, hazards and risks related to bisphenol A (BPA): the tolerable daily intake of EFSA unchanged in 2010

Two recent elements feed the present factual and scientific debate on bisphenol A :

1. The European Food Safety Agency (EFSA) updated advice

The European Food Safety Agency announced in September 2010 that its scientific panel for food contact materials –   enzymes, flavourings and processing aids – completed a detailed and comprehensive review of recent scientific literature and studies on the toxicity of bisphenol A at low doses.

The EFSA scientists conclude they could not identify any new evidence which would lead them to revise the current Tolerable Daily Intake (TDI) for BPA of 0.05 mg/kg body weight set by EFSA in its 2006 opinion and re-confirmed in its 2008 opinion.

Bisphenol A (BPA) is used in the manufacture of polycarbonate plastic found in such items as reusable drinking bottles, infant feeding bottles and storage containers, and in the lining of some food and drinks cans. Due to the possible association of BPA with negative health effects, the endocrine active substance has been the subject of considerable attention worldwide.

EFSA has held consultations in recent months with experts from across Europe and scientific discussions with several international risk assessment authorities, such as the U.S. Food and Drug Administration (FDA), Health Canada and the World Health Organisation (WHO) on the subject of BPA, including the design of scientific studies on BPA, toxicological aspects and the strengths and weaknesses of certain studies.

EFSA on its side is further monitoring ongoing publications on BPA and is aware of studies being carried out and planned worldwide. Furthermore, some Panel members are involved in EFSA’s ongoing work to monitor trends and developments in the assessment of health risks of endocrine active substances.

2. An Expert consultation organiszed by WHO and FAO in November 2010

EFSA  also contributed to an expert consultation organised by the WHO and the Food and Agriculture Organisation (FAO) in November 2010 on the safety of BPA.

http://www.who.int/foodsafety/chem/chemicals/BPA_Summary2010.pdf

In summary, this Expert Meeting concluded that:

Establishing a “safe” exposure level for BPA continues to be hampered by a lack of data from experimental animal studies that are suitable for risk assessment. Many research studies have design and analysis issues that limit their utility for this purpose.

Controversy continues over the biological significance of many of the more sensitive end-points and whether studies that have assessed only conventional end-points are adequate for detection of all potentially relevant effects. Continued research into the toxicokinetics of BPA and its estrogenic and other mechanisms of action will be needed before it is possible to determine the appropriate points of departure (e.g. NOAEL, LOAEL, benchmark dose) for human risk assessment with confidence.

  1. For many end-points, points of departure are much higher than human exposure. Hence, there is no health concern for these end-points.
  2. • Studies on developmental and reproductive toxicity in which conventional end-points were evaluated have shown effects only at high doses, if at all.
  3.  • However, some emerging new end-points (sex-specific neurodevelopment, anxiety, preneoplastic changes in mammary glands and prostate in rats, impaired sperm parameters) in a few studies show associations at lower levels.
      However, it is difficult to interpret these findings, taking into account all available kinetic data and current understanding of classical estrogenic activity. However, new studies indicate that BPA may also act through other mechanisms.The points of departure for these low-dose effects are close to the estimated human exposure, so there would be potential for concern if their toxicological significance were to be confirmed.There is considerable uncertainty regarding the validity and relevance of these observations. While it would be premature to conclude that these evaluations provide a realistic estimate of the human health risk, given the uncertainties, these findings should drive the direction of future research with the objective of reducing this uncertainty.Read the full EFSA

press release

      and a small dossier on BPA :

http://www.efsa.europa.eu/en/ceftopics/topic/bisphenol.htm?wtrl=01

      See also the full

Scientific Opinion on Bisphenol A: evaluation of a study investigating its neurodevelopmental toxicity, review of recent scientific literature on its toxicity and advice on the Danish risk assessment of Bisphenol A

    (2010)

For some elements of context on endocrine disruptors in general :

read the GreenFacts summary on Endocrine Disruptors

Note : the content of the short presentations of international reports on health and the environment  presented on the blog of Greenfacts are not verified by its Scientific Board

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