Studies feed fears over bisphenol A health threat

Recent reviews of the toxicity of the oestrogenic chemical intermediate bisphenol A in North America have rekindled fears over health impacts on infants and foetuses. The Canadian Government and US politicians are debating bans on the compound in baby products, while retailers have promised to withdraw them.

Draft health and environmental reviews of the plastics intermediate bisphenol A in Canada and the US have raised fears that levels in food may be affecting the development of children.

Bisphenol A is used in polycarbonate plastics and epoxy resins, but it is suspected of oestrogenic and endocrine disrupting effects. The main human exposure route is in food. The compound migrates from plastic containers such as reusable polycarbonate containers including baby bottles and epoxy can linings.

The Canadian Government issued a draft risk assessment report on bisphenol A on 19 April that concluded the chemical "may constitute a danger… to human life or health."1 The report found potential for concern over human reproductive and developmental toxicity. Data from animal tests suggest the safety margins for neurodevelopmental and behavioural effects in humans are negligible. Infants and unborn babies are most at risk.

The report also looked at the environmental effects. It highlighted the chemical’s persistence under anoxic or anaerobic conditions and its acute toxicity to aquatic organisms. Bisphenol A may also accumulate in some species that cannot metabolise it.

Alongside the report, Canadian ministers announced a public consultation on whether to ban the import and sale of baby bottles made from polycarbonate.

Meanwhile, the US National Toxicology Program (NTP) - part of the National Institutes of Health - published a draft brief on 14 April which also found cause for "some concern" over foetus, infant and child exposure to bisphenol A.2 The brief noted that neural and behavioural effects might occur at current exposure levels. Bisphenol A could also cause changes to the prostate and mammary glands, which might increase susceptibility to cancer in later life and bring on the early onset of puberty in girls. The NTP agreed with a US study last year by a Center for the Evaluation of Risks to Human Reproduction (CERHR) expert panel, which warned of the chemical’s risks (ENDS Report 391, p 5 ).

The NTP study also sparked a political reaction. Democrat senator Charles Schumer proposed a bill to ban the use of bisphenol A in plastic products made for infants and children, and require studies into the health risks posed by the chemical.

North American retailers have promised to remove bisphenol A from products. Toys ‘R’ Us said it was working with manufacturers to phase out all baby feeding products with the compound before the end of 2008. Wal-Mart is also reported to be taking action.

One US manufacturer, Nalgene, confirmed to ENDS that it will stop making food contact containers from polycarbonate. Concern is such that the US House of Representatives Committee on Energy and Commerce wrote to four major infant formula manufacturers to ask them to voluntarily remove bisphenol A from their packaging. "We believe that health risks... are serious enough to warrant immediate action," the letter said.

The moves cast a shadow over the future of the compound, of which 3 million tonnes are produced globally each year. It is seen as essential in many applications, although UK retailers such as Boots have tried to remove it in packaging (ENDS Report 339, pp 32-33 ).