Chemical study on Bisphenol A

General Bisphenol A is used as an intermediate (binding, plasticizing, hardening) in plastics, paints/lacquers, binding materials and filling-in materials. The substrate is mainly used for the production of polycarbonate resins (71%) and epoxy resins (27%). Furthermore bisphenol A is used as an additive for flame-retardants, brake fluids and thermal papers. The current (1999) world-wide production of bisphenol A is approx. 2,000 ktonnes/year. Over the next 5 years, overall production is believed to grow to around 3,500 ktonnes/year in 2005. Sources and emissions The production of bisphenol A in the Netherlands in 1999 was around 280 ktonnes/year, which is approx. 35% of the total production in Europe and around 14% of the total world production. A review of all produced, used amounts and emissions is given in Table 1. Over the years bisphenol A consumption has more than doubled. From 1993 to 1996, total consumption for polycarbonates grew with 11.6% per year and is expected to continue to grow at an average annual rate of 7.6% during the period 1996-2001. Bisphenol A consumption for the production of epoxy resins will also grow but more moderately. In 1999 annual bisphenol A consumption in Europe is estimated at 680 ktonnes. Total polycarbonate consumption in the Netherlands is 14 ktonnes/year while other consumption of bisphenol A based products is 11 ktonnes. Emissions of bisphenol A may occur during bisphenol A production, production of products using bisphenol A and from products in-use. Emission during bisphenol A production is around 2 tonnes/year to surface waters and 1 tonne to air. The most important emissions during bisphenol A product processing occur during production of phenoplast cast resins (43 tonnes to water in Europe), thermal paper production (151 tonnes to water in Europe) and the use of bisphenol A as inhibitor during PVC production (25 tonnes to water in Europe). Total emissions are 2.1 tonnes to air, 199 tonnes to water and 30 tonnes to soil in Europe. The specific emissions for the Netherlands are unknown. Emissions from products in-use are estimated at 160 kg from polycarbonates and <1 kg of epoxy resins used in can lining. Furthermore losses from PVC articles inuse are 20 tonnes to air and 30 tonnes to water. Concerning emissions are the leaches of bisphenol A from baby bottles, cans and flasks to food. In baby bottles in a study an average of 56 ppm is found to leach and in another study a maximum of 20 mg BADGE/kg plastic leached from cans. Concentrations in food are not available. Environmental characteristics and toxicity in aquatic systems Bisphenol A has a moderately high water solubility (120 mg/l) and a low vapour pressure (5.32 10-5 Pa). The log Kow value varies from 2.2 to 3.4. As a result of these characteristics bisphenol A has a tendency to partition into water and the rate of evaporation from soil and water will be low. The log Kow indicates a low bioaccumulative potential. Based on experimental data the BCF varies from 1 to 196, which also indicates a low potential to bioaccumulate in aquatic species. Bisphenol A is not susceptible to hydrolysis but has a potential to photolyse in water if not bound to organic matters (particulate phase) in water. From biodegradation tests bisphenol A is found to be not readily biodegradable, but to be inherently biodegradable. However measured levels of bisphenol A before and after wastewater treatment suggest a high level of removal. After a short period of adaptation, bisphenol A seems to be readily biodegradable. The same goes for the biodegradation in natural waters after acclimatisation. Bisphenol A is acutely moderately toxic to freshwater and marine algae, fish and crustaceans. Based on chronic tests bisphenol A is very slightly to slightly toxic in freswater and moderately toxic in marine water. Based on 1 chronic study with endocrine effects (skewed sex-ratio) with an amphibian, bisphenol A is very toxic. Occurrence and behaviour in aquatic systems In the Netherlands concentrations of 21 to 40 ng/l have been found in fresh waters and of 3.5 to 23 ng/l in marine waters. The concentrations in industrial and urban wastewater are in the range of 300 to 700 ng/l but for two locations, where the concentration reached the 2 mg/l. Bisphenol A concentration in sewerage and wastewater sludge ranged from <116 to 7000 ng/l (15-270 ng/g dry matter). In sediments concentrations were below the detection limit of 0.05 - 0.25 ? g/kg dry matter. There are no data on concentrations in other environmental compartments. In Japan concentrations of 60 to 1900 ng/l have been measured in surface water in 1974-1978. All measured concentrations are considerable lower than the calculated HTBA value of 247 mg/kg and lower than the calculated iMPCs of 0.064 mg/l and 22.9 mg/kg for resp. surface water and sediment. Policy No specific quality standards are derived for bisphenol A. Bisphenol A is not regulated. However there are some regulations with regard to the maximum limits of bisphenol A in food and migration from materials that come into contact with food. Conclusions and recommendations From the results of this study can be concluded that bisphenol is widely used and therefore also widely spread in the environment. Current data on the release and distribution of bisphenol A are limited, but suggest that the substance will primarily be available in the aquatic phase in surface waters and probably will hardly bioaccumulate in organisms. Estimates of emissions to the environment demonstrate that significant amounts may be released to surface water by discharge of treated wastewater. For evaluation of the aquatic toxicity of bisphenol A, a limited amount of data was available. Considering the large emission estimates to surface water, their high tendency to spread in aquatic systems and the fact that bisphenol A is moderately toxic to aquatic organisms, it is recommended to perform an additional study on these compounds with emphasis on collection and verification of emission factors and furthermore to generate new toxicity data. Especially in the area of endocrine disrupting effects more research should be done because these effects concentration may be a factor 100-1000 lower. Further research into concentrations in food are also considered important in relation to the leaching of bisphenol A from baby bottles, flasks and cans.