Official views on bisphenol A

SummaryBisphenol A has been used in the production of food contact materials since the 1960s. Some recent findings point to possible low dose effects at levels of current human exposure. As a precaution some official authorities have introduced limited bans on bisphenol A to protect babies and young children, while others take a wait and see approach pointing to the need for more research.

bisphenol A

Structure of bisphenol A (credit: Wikipedia)

The use of the industrial chemical bisphenol A (BPA) to make food contact plastics and resins, although questioned for some time as a potential risk to human health by some scientists, is still approved by official authorities in most countries. Polycarbonate baby bottles is a recent exception. Question is, with some new scientific findings, will official risk assessment authorities change their general view and will risk managers take further action?

The European Union situation

BPA is permitted for use in food contact materials in the European Union (EU), most recently as listed under Regulation 10/2011/EU. The European Food Safety Authority (EFSA) completed a full risk assessment of BPA in 2006 and set a Tolerable Daily Intake (TDI) of 0.05 mg/kg body weight per day for the substance – that is the amount that can be ingested daily over a lifetime without appreciable risk. Since the initial opinion, EFSA has been asked three times to review the initial assessment and as a result published updated scientific advice in 2008, 2010 and 2011. EFSA also evaluated intakes of BPA through food and drink, for adults, infants and children and found that they were all well below the TDI.

Due to the controversial debate on BPA and despite EFSA’s view on the safety of BPA, the EU member states Denmark and France banned BPA in baby bottles in 2010. The ban was imposed for reasons of precautionary consumer protection. In order to create a consistent legal framework within the EU and following a similar move in Canada, the European Commission adopted Directive 2011/8/EU in January 2011 prohibiting the use of BPA for the manufacture of polycarbonate infant feeding bottles and their placing on the market within the EU.

Contrary to the prevailing view of EFSA, on 27 September 2011 the French L’Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail (ANSES) published two reports on bisphenol A reaching a different conclusion. One report related to the health effects associated with exposure to BPA while the other concerned its uses. In the report on health effects – “Effets sanitaires du bisphénol A” – ANSES concluded that health effects have been proven in animals and suspected in humans, even at low levels of exposure below current regulatory thresholds. On the basis of these findings it recommended that exposure to bisphenol A should be limited in the most susceptible populations of infants, young children, pregnant and breastfeeding women. A previous Danish report produced by the DTU Fødevareinstituttet on behalf of the Danish government reached similar conclusions. It noted that neurodevelopment effects were seen in young male rats even at low doses of BPA raising some concern of possible human effects.

The CEF Panel did not consider that the information in the ANSES report would immediately change the views the Panel expressed in 2010, but wanted more time to review in depth the new studies. Consequently, in February 2012, the CEF Panel decided to undertake a full re-evaluation of the human risks associated with exposure to BPA through both dietary and non-dietary sources. The intention is to review all the available data and scientific studies on exposure published since 2006. The Panel will further evaluate uncertainties about the possible relevance to human health of some BPA-related effects observed in rodents at low dose levels. New findings from ongoing studies on low dose effects as well as on dietary and non-dietary exposure to BPA will be considered as they become available during 2012, with the intention to publish the new opinion by May 2013.

The Canadian situation

Health Canada’s Food Directorate has conducted periodic reviews of BPA as new information has become available relating to its toxicity and potential exposure from food packaging applications. The purpose of these reviews was to determine whether dietary exposure to BPA could pose a health risk to consumers. Based on the overall weight of evidence, the view is still that current dietary exposure to BPA through food packaging uses is not expected to pose a health risk to the general population, including newborns and infants.

However, due to the uncertainty raised in some animal studies relating to the potential effects of low levels of BPA, the Government of Canada banned the use of BPA in baby bottles in March 2010 to enhance the protection of infants and young children. It further added BPA to the list of substances deemed potentially harmful to health or the environment in October the same year to make it easier to take further action should this be deemed necessary.

The Bureau of Chemical Safety, in the Food Directorate of Health Canada, is investing further resources in exploring the potential impact of BPA on the health of the Canadian population. It will improve estimates of dietary exposure to BPA from all Canadian food sources. It is also a partner in assessing information gaps on the occurrence and significance of BPA in human milk from Canadian mothers in a project funded by Health Canada, the Canadian Institutes of Health Research and the Ontario Ministry of the Environment.

The situation in the USA

BPA was first approved by the Food and Drug Administration in the early 1960s. Due to some concerns raised, the FDA released a draft report in August 2008 finding that BPA remained safe in food contact materials. However, a few months later a subcommittee of FDA’s science board raised questions about whether the review had adequately considered the most recent scientific information available.

On January 15, 2010 and again on March 30, 2012, the FDA issued interim updates on BPA. They claimed that studies employing standardised toxicity tests had thus far supported the safety of current low levels of human exposure to BPA. However, on the basis of results from recent studies using novel approaches to test for subtle effects, FDA, supported by the view of the National Toxicology Program at the National Institutes of Health, expressed some concern about the potential effects of BPA on the brain, behaviour, and prostate gland in foetuses, infants, and young children. This concern was expressed because it was noted that developmental changes in some animal studies occurred at BPA exposure levels similar to those experienced by humans. A collaborative effort is underway to carry out further in-depth studies to clarify the outstanding uncertainties about the risks of BPA.

While awaiting the new results, FDA expressed support for actions to stop the production of BPA-containing baby bottles and infant feeding cups for the U.S. market and the recommendations issued by the Department of Health and Human Services for infant feeding and food preparation to reduce exposure to BPA.

The Australian situation

The Australian Government has limited its action on BPA to an introduction of a voluntary phase out of BPA use in polycarbonate baby bottles. Food Standards Australia New Zealand (FSANZ) is firm in its view that there are no health issues associated with BPA at the levels people are exposed to. They state that extremely large amounts of food and beverages would have to be consumed to even reach still acceptable intake level.

There is no suggestions of further activities as they claim that countries that banned the use of BPA in some products did so without any support of risk assessment conclusions on the safety of BPA. To further support this view the FSANZ website lists shortcomings in 17 scientific studies purporting to show the toxicity of BPA.

The international view

According to the World Health Organization website the scientific controversy around the safety of BPA is driven by the disparate results reported in the many studies exploring toxicity and endocrine activity of BPA in animals. This has led to different risk management decisions taken by national authorities. The issue has also received much attention in the media and among the general public. In light of possible adverse human health effects at low doses of BPA, especially on reproduction, the nervous system and on behavioural development, and considering the relatively higher exposure of very young children compared with adults, a meeting of ad hoc experts was jointly organised by FAO and WHO in late 2010 to assess the safety of BPA.

It was difficult for the meeting to reach definitive conclusions on the safety of BPA because of a lack of data from experimental animal studies suitable for risk assessment. Controversy persisted over the biological significance of many of the more sensitive end-points and it was uncertain if all relevant end-points had been covered by the studies used for past risk assessments.

It was clear that for many traditional end-points, human exposure was much too low to be of any health concern. However, for some emerging new end-points (sex-specific neurodevelopment, anxiety, pre-neoplastic changes in mammary glands and prostate in rats, and impaired sperm parameters) a few studies showed associations at levels close to the estimated human exposure, which was clearly of concern if their toxicological significance were to be confirmed. Further research would be needed before these results could provide a basis for a realistic estimate of the human health risk.

The maligned bisphenol A

Summary – Bisphenol A is an industrial chemical that has been present in many hard plastic bottles and metal-based food and beverage cans since the 1960s. Recent studies using novel approaches to test for subtle effects raised some concern about its potential influence on the brain, behaviour and prostate gland development in foetuses, infants and young children. It is currently under extensive review.

Bisphenol A (BPA) is an industrial chemical used since the 1960’s as an ingredient in making a clear plastic known as polycarbonate. Polycarbonate is used to make a variety of common products including baby and water bottles, sports equipment, medical and dental devices, dental fillings and sealants, CDs and DVDs, household electronics, and eyeglass lenses. BPA is also found in epoxy resins, which act as a protective lining on the inside of metal-based food and beverage cans. It can leach into food, and a study of over 2,000 people found that more than 90 percent of them had BPA in their urine. Traces have also been found in breast milk, the blood of pregnant women and umbilical cord blood.

BPA is permitted for use in food contact materials in the European Union (EU) and in most other countries.  In the past, the European’s Scientific Committee on Food, the European Chemicals Bureau, the European Food Safety Authority, and the US Food and Drug Administration all concluded that current levels of BPA present no risk to the general population. However, recently it was found to exert detectable hormone-like properties, raising concerns about its presence in consumer products and foods contained in such products. Starting in 2008, several governments questioned its safety, prompting some retailers to voluntarily withdraw polycarbonate products. Canada was the first country to ban the use of BPA in baby bottles from 2010 followed by the European Commission in January 2011. In 2012, also the United States banned the use of BPA in baby bottles including in infant feeding cups.

Bisphenol A toxicity

There is a great diversity of opinion about the health effects of BPA. Overall, empirical evidence in support of negative health effects of BPA varies significantly across studies.  Standardised toxicity tests used globally for regulatory decision-making long supported the safety of current low levels of human exposure to BPA. However, results of recent studies using novel approaches and different endpoints found detrimental effects in laboratory animals at very low doses similar to estimated human exposure.

Several new studies evaluated developmental or behavioural effects that are not typically assessed in standardised tests. For example, perinatal exposure to BPA in rodents modified sex differences in the brain. In mice, prenatal exposure to BPA was associated with increased anxiety, aggression and cognitive impairment. In the offspring of BPA-exposed monkeys, males displayed less social behaviours and were more exploratory. In humans, BPA exposure during gestation has been associated with hyperactivity and aggression in young children and with anxiety and depression in older children. Together, these reports and many others demonstrate that BPA exposure during gestation affects several types of behaviours in a number of species.

It is clear that bisphenol A is a weak endocrine disruptor, which can mimic oestrogen and may lead to negative health effects. Early developmental stages seem to be the period of greatest sensitivity to its effects. Regulatory bodies have determined safety levels for humans, but those safety levels are being questioned or are under review as a result of the new findings. Experts in the field of endocrine disruptors have stated that the entire population may suffer adverse health effects from current BPA levels. In 2009, the Endocrine Society released a statement citing the adverse effects of endocrine-disrupting chemicals, and the controversy surrounding BPA.

In 2010, the WHO organised an expert meeting to review toxicological and health aspects of BPA supported by Health Canada, the European Food Safety Authority, the U.S. National Institute of Environmental Health Sciences and the US Food and Drug Administration. Although the meeting concluded that doses much higher than estimated human exposure were necessary for most toxicological effects, it did agree that for some emerging effects, like sex-specific neurodevelopment, anxiety, preneoplastic changes in mammary glands and prostate in rats, and impaired sperm parameters, a few studies showed associations at levels close to estimated human exposure. Because of the considerable uncertainty of the validity and relevance of these observations it was recommended that further research should be undertaken to reduce the uncertainty.

Re-evaluation of human risks

EFSA completed a full risk assessment of BPA in 2006 and set a limit of 0.05 mg/kg body weight per day that could be ingested daily over a lifetime without appreciable risk (Tolerable Daily Intake – TDI). It evaluated intakes of BPA through food and drink, for adults, infants and children and found that they were all well below the TDI.

EFSA has updated its scientific advice on BPA several times since 2006, most recently updating its risk assessment in 2011, reaching similar conclusions.

In February 2012, following further consideration of new scientific studies, EFSA decided to undertake a full re-evaluation of the human risks associated with exposure to BPA through the diet, also taking into consideration the contribution of non-dietary sources to the overall exposure to BPA. The new opinion will review all the available data and scientific studies on dietary exposure published since EFSA’s 2006 Opinion. The Panel will further evaluate uncertainties about the possible relevance to human health of some BPA-related effects observed in rodents at low dose levels.

FDA is also continuing to consider the low dose toxicity studies of BPA as well as other recent peer-reviewed studies related to BPA. At this stage, FDA has stated its current perspective on BPA, its support for further studies, its establishment of a public docket for its assessment of BPA use in food contact applications. FDA has issued interim public health recommendations, including its view of the appropriate regulatory framework for BPA use in food contact applications. It is expressing the wish to pursue the issue in collaboration with international partners.