EU agency sets maximum limit for bisphenol A
intakes of bisphenol A (BPA), a chemical implicated as a potential
carcinogen and widely used in plastic food packaging and cans.
Setting a Tolerable Daily Intake (TDI) on BPA provides guidance on the use of the chemical toregulators and processors as this can be used as the basis for scientific risk assessments onwhether it can be used, reduced or banned.
People are exposed to BPA in food through its use in certain plastic and other materials that are used in products such as bottles and cans. The chemial has been found to migrate in small amounts into foods and beverages stored in materials containing the substance.
BPA is used to manufacture polycarbonate, a rigid plastic used to make infant feeding bottles, plates, mugs, jugs, beakers, microwave oven ware and storage containers. It is also used in the production of the epoxy-phenolic resins that form internal protective linings for cans and metal lids. The resins are also used as coatings for water storage tanks and wine vats.
In publishing its decision the European Food Safety Authority (EFSA) said its scientific panel on food contact materials concluded that the setting of a full rather than a temporary TDI was needed, including a review of all available new data from the last five years.
Having considered both the pre-2002 and new studies available, the EFSA scientific panel concluded that the no-observed-adverse-effect level (NOAEL) of five milligram/kg body weight/day identified in the previous evaluation in 2002, remains valid.
The panel also concluded that reports of low-dose endocrine effects of BPA in rodents did not demonstrate such activity in ways that were "robust or reproducible".
"New studies have shown significant differences between humans and rodents, such as the fact that people metabolise and excrete BPA from their system far more quickly than rodents, further limiting the relevance of low-dose effects of BPA reported in some rodent studies for human risk assessment," EFSA stated. "Studies have also shown that mice are particularly sensitive to oestrogens. Given that BPA is a weak oestrogen, the absence of adverse effects at 5 milligram/kg body weight and below in a new robust study on mice and two generations of their offspring adds further confidence to the risk assessment."
EFSA said its re-evaluation of BPA focused on effects on reproduction and the endocrine system, about which it said there has been much scientific debate.
The EFSA scientific panel noted that conservative estimates of current daily exposure to the chemical put it at 30 per cent of the TDI in all population groups. "These exposure estimates include BPA migration into canned foods and into food in contact with PC table ware or storage receptacles," EFSA stated.
The estimates do not include either potential migration of BPA from receptacles into food during microwave heating or into drinking water due to the use of resins in water pipes and in water storage tanks.
Recent US and Japanese scientific studies caused a scare over BPA in 2005. The US study found low doses of BPA could harm the development of young brains. Another US study found that BPA increased breast cancer cell growth. The US studies were done on rats.
The Japanese study indicated a link between recurrent miscarriages in women and BPA.
