Environment, Health and Safety Committee Note on: WHY DO WE

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1 Environment, Health and Safety Committee Note on: WHY DO WE WORRY ABOUT BISPHENOL-A INTRODUCTION Public concerns over bisphenol-A have come to prominence in recent years, This Note was produced by a particularly in relation to its presence in babys plastic feeding bottles and possible Working Party of the health effects on infants. Although there is no conclusive evidence that any adverse Environment, Health and effects are occurring in infants as a result of exposure to bisphenol-A, the Safety Committee [EHSC] precautionary approach taken by the European Union (EU) has led to a ban of the of the Royal Society of substance in babys bottles in 2011. However the toxicology of bisphenol-A, Chemistry. particularly the potential for effects on the human endocrine system, remains a controversial subject. This Note aims to provide some insight into our current The Society is a registered understanding of the risks associated with bisphenol-A. Charity. Its Royal Charter obliges it to serve the public WHAT IS BISPHENOL-A interest by acting in an independent advisory capacity. Bisphenol-A, or 4,4'-dihydroxy-2,2-diphenylpropane, is an organic compound with In order to meet this obligation two phenolic functional groups. It is manufactured from phenol and acetone in a the members of the EHSC are condensation reaction. drawn from a wide range of backgrounds and serve on the USES OF BISPHENOL-A committee as individual experts and not as Global production of bisphenol-A was approximately 3.8 million tonnes in 2006. The representatives of their main uses can be broadly divided into those where bisphenol-A is reacted with other employer. substances in the production of polymers or resins (the major use) and those where it is used as an additive and/or anti-oxidant (relatively minor use). This distinction is The EHSC welcomes important as it affects the potential for subsequent exposure to bisphenol-A in the comments on this Note. final product. Please send them to the Committee Secretary: Where bisphenol-A is reacted during the manufacture of resins and polymers, it is Environment, Health and chemically changed during the process and the only bisphenol-A remaining in the Safety Committee final product is a small amount of unreacted (residual) bisphenol-A (for example the Royal Society of Chemistry maximum residual bisphenol-A content in polycarbonate resins is around 50 mg/kg Burlington House resin but the typical level is

2 Production of tetrabromobisphenol-A (around 2% of the total use but this process is not carried out in the EU). Tetrabromobisphenol-A is used as a flame retardant. Other minor uses include the following. PVC production and processing. Ethoxylated bisphenol-A manufacture. Thermal paper manufacture. Manufacture of polyols/polyurethane. Manufacture of modified polyamides. Tyre manufacture. Brake fluids. HOW DOES BISPHENOL-A WORK Bisphenol-A finds use as an intermediate in the manufacture of a number of polymers and resins as its molecule contains two reactive phenol groups. This means that the substance can be used in a number of polymerisation reactions where it becomes chemically bound into the polymer or resin chain. BENEFITS OF THE USE OF BISPHENOL-A Bisphenol-A is used to manufacture a number of plastics and resins that provide benefits to society. For example, polycarbonate plastic has good durability and heat stability, is lightweight and transparent and has good shatter resistance. Products manufactured from polycarbonate include sheets for roofing and glazing, optical media (CDs, DVDs), parts for electrical/electronics and automotive industries, spectacle lenses and safety equipment, medical devices and food contact containers such as water bottles and baby bottles. Uses of epoxy resins manufactured using bisphenol-A include protective coatings, structural composites, electrical laminates and adhesives. Examples of applications include marine protective coatings, powder coatings for construction, furniture, pipes and fittings and automotive applications, printed circuit boards, flooring and construction coatings and can linings and coatings. The use in can linings for food is important for prevention of corrosion of the can and subsequent contamination of the food with metals and tainting/spoiling of the food by bacterial contamination. There are numerous other examples of products manufactured using plastics or resins derived from bisphenol-A. RISKS DURING MANUFACTURE, USE AND DISPOSAL In most applications of bisphenol-A the substance is reacted during the process and so only a residual amount of bisphenol-A remains in the product. Exposure to workers and the environment can occur at industrial sites producing or using bisphenol-A. However risks from this exposure are controlled through legislation such as Control of Substances Hazardous to Health (COSHH) and REACH (Registration, Evaluation, Authorisation and restriction of CHemicals.). Exposures of the general public are thought to occur mainly from migration of trace amounts of bisphenol-A from food contact materials into food. Such materials include can linings and polycarbonate bottles (including baby feeding bottles). The total daily exposure from such sources has been conservatively estimated by the European Food Safety Authority (EFSA) (http://www.efsa.europa.eu/en/efsajournal/pub/428.htm) to be up to 0.0015 mg/kg body weight/day in adults, up to 0.0053 mg/kg bw/day in young children and up to 0.013 mg/kg body weight/day in 6-12 month infants. Exposure of the general public is also possible from other applications, for example from use in thermal paper etc. Bisphenol-A can also be released from some types of dental sealants where a derivative of bisphenol-A is used. Bisphenol-A is classified as toxic to reproduction category 2 under the EU Classification, Labelling and Packaging (CLP) Regulations and is suspected of damaging fertility. This means that effects on reproduction have been demonstrated in animals but there is limited evidence of relevance to humans. Other known health effects for which bisphenol-A is classified under the CLP Regulations include skin sensitisation, irritation to the respiratory system and serious eye damage. There has been much debate over the health effects of bisphenol-A, particularly in relation to its possible effects on the human endocrine system which, produces hormones that regulate various human functions, including metabolism, fertility, growth and development, organ function, and mood. Many tests have been carried out on these possible effects and the available data have been extensively reviewed by regulators worldwide. In September 2010 the EFSA concluded that a Tolerable Daily Intake (TDI) of 0.05 mg/kg body weight/day was appropriate for bisphenol-A exposure via food, based on an assessment of the available data on reproduction and possible effects on the endocrine system. The current exposure of the general public is generally below this TDI value (see above). The EFSA also concluded that the results of some studies carried out on developing animals were suggestive, but not

3 conclusive, of effects of possible toxicological significance (for example in relation to biochemical changes in brain, immune-modulatory effects and enhanced susceptibility to breast tumours), that may not be protected against with the above TDI. However there are many shortcomings with these studies and the EFSA concluded that the relevance of these findings to human health cannot be assessed at present. This has led to some precautionary action in the EU (see Control Measures). When released to the environment, bisphenol-A is rapidly degraded and does not bioaccumulate in animals or the food chain. However, reproductive effects of bisphenol-A in fish have been demonstrated in laboratory test systems. CONTROL MEASURES Bisphenol-A has been registered under the EU REACH Regulation. As part of this process, the appropriate risk management measures needed to limit exposure of humans and the environment have been identified and applied at industrial sites producing and using bisphenol-A. As a result of concerns from the possible leaching of bisphenol-A from bottles manufactured from polycarbonate into food when heated, EU-wide legislation on the use of bisphenol-A in feeding bottles for infants has been instigated. Since the 1st of June 2011, this legislation effectively prohibits the use of bisphenol-A in the manufacture of feeding bottles. The same legislation also imposes a Specific Migration Limit (SML) for food contact materials in order to protect consumers from migration of bisphenol-A into food from such materials. The current EU-wide SML for food contact material is 0.6 mg bisphenol-A per kg of food. ALTERNATIVES As much of the concern over bisphenol-A has focused on its possible presence in food from food contact materials and bottles, bisphenol-A free alternatives are increasingly available. The alternatives are generally plastics or resins other than polycarbonate or epoxy resins. UNCERTAINTIES The main uncertainties regarding the toxicology of bisphenol-A relate to its possible effects on the endocrine system of humans and whether such effects can occur at very low doses. This is an area of active research and controversy. As noted above, the EU regulatory authorities have recently concluded that there is suggestive, but not conclusive, evidence that such effects are relevant in humans and a precautionary approach has been taken to protect the most vulnerable populations. Note was prepared by a Working Party of the RSC Environment, Health and Safety Committee. The members of the Working Party were: Dr I Wrightson (Chairman), S J Cooper, Dr M Crookes, P Jackson, Dr N King, Dr P Lewis, J Larner, Dr D H Lohmann, Dr C Maxwell, D M Sanderson, Dr C Watts, and Dr S Lipworth (Secretary). This Note is also available on the RSC website: http://www.rsc.org

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