California can include bisphenol A (BPA) on its list of chemicals that are known to cause cancer or reproductive harm, a state appeals court ruled Oct. 19. The decision is a loss for chemical manufacturers, who have been pushing for years to keep BPA off the list.
Under California’s Proposition 65 law, manufacturers must put warning labels on products sold in California that contain chemicals on the list. Such warnings will now be required for products containing BPA. The chemical is found in some food and beverage packaging and polycarbonate plastic goods.
A chemical can be added to the list if the World Health Organization’s cancer agency declares the chemical causes cancer in humans or laboratory animals; if one of the state’s two independent committees of scientific experts recommends listing; or if an authoritative body, such as the US National Toxicology Program (NTP) or another federal agency, identifies the chemical as causing cancer or reproductive harm.
California listed BPA as a reproductive toxicant in 2013, based on a 2008 report by the NTP that found “some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to bisphenol A.” The NTP report relied on animal studies, from which it concluded “the possibility that bisphenol A may alter human development cannot be dismissed.”
The American Chemistry Council (ACC), on behalf of chemical manufacturers, challenged the decision. The ACC argued that the California Office of Environmental Health Hazard Assessment (OEHHA) did not have sufficient evidence to identify BPA as causing reproductive toxicity under Proposition 65. The industry group claimed that animal studies provide only limited evidence for developmental effects in humans. The group also asserted that OEHHA abused its discretion by ignoring a 2009 recommendation from a committee of scientific experts appointed by the California governor not to list BPA as a reproductive toxicant.
A lower court rejected industry’s argument, and the ACC appealed the decision in 2015. The appeals court agreed with the lower court and affirmed the judgment.
OEHHA did not abuse its discretion by concluding that adverse effects observed at high doses in animal studies are biologically plausible in humans, Justice William J. Murray Jr. stated in the court opinion. The agency’s position is based on the presumption that “chemicals that cause harm in experimental animals will also cause similar harm in humans in the absence of evidence to the contrary,” he wrote.