In a move that could signal a new approach to regulating potentially hazardous compounds, European health experts are recommending a drastic cut in the allowable human consumption of a common chemical in food. The European Food Safety Authority (EFSA) has proposed reducing by a factor of 100,000 the tolerable daily intake of bisphenol A (BPA), an endocrine disruptor that interferes with hormone systems and has been linked to disease.
The huge reduction could lead to a de facto ban on the cheap and durable material in food-related uses, such as lining metal cans. And it could mark a shift in how European regulators use research findings in setting exposure limits. Traditionally, those limits have been shaped by large studies directly linking a chemical to an increased risk of disease. In this case, however, risk assessors put greater weight on smaller studies showing low levels of BPA can cause subtle changes that could lead to future health problems. This approach, if adopted widely, could justify much lower exposure limits for other chemicals.
“It’s a big deal,” says Laura Vandenberg, an endocrinologist at the University of Massachusetts, Amherst, who calls the proposed limit “a gravestone for BPA in Europe.” Environmental and public health advocates are praising the proposal, which is open for comment until 22 February.
Industry groups, however, are dismayed. Plastics Europe argues EFSA ignored relevant, older studies in setting the standard. “If the entire scientific evidence had been evaluated … we are convinced that the conclusions would have been different,” says Jasmin Bird, a spokesperson for the group. Jennifer Garfinkel, a spokesperson for the industry-backed American Chemistry Council, calls EFSA’s proposal “unprecedented,” noting that the U.S. Food and Drug Administration (FDA) has concluded that BPA is safe at current exposures.
Bisphenol A is used in many plastics, including thermal paper for receipts, but most people are exposed through food. BPA leaches out of polycarbonates used to make bottles and food containers, for example, as well as the epoxy liners used to protect steel and aluminum cans from acidic food and beverages.
In 2014, after reviewing recent studies, an expert panel assembled by EFSA recommended temporarily lowering the tolerable daily intake from 50 to 4 micrograms per kilogram of body weight per day. The panel was especially intrigued by studies suggesting BPA altered the immune systems of rats. Before making a firmer recommendation, however, the EFSA panel wanted to see the results of a $30 million research program funded by the U.S. government.
This program, which ran from 2014 to 2018, compared academic research studies with a large study of rats exposed to BPA—the kind of standardized animal study that industry and FDA typically rely on to assess health risks. The rat study supported FDA’s recommended daily limit of 5 micrograms. But the academic studies, which included analyses of how low doses affected mammary glands in lab animals, produced results that EFSA experts considered worrisome.
To set an intake limit, the EFSA panel looked at the study in which the lowest dose produced a biological effect. That research, conducted at Anhui Medical University in China, showed that as BPA exposure rose in mice, so did the numbers of immune cells that are key players in inflammatory and autoimmune diseases. Based on that finding, the panel recommended cutting the BPA limit 100,000-fold, to 0.04 nanograms.
Although EFSA says it did not change its basic approach in re-evaluating BPA, scientists say risk assessors are giving increasing weight to smaller research studies that agency experts have traditionally discounted. “It’s a tremendous change,” says Ángel Nadal, a physiologist at the Miguel Hernández University of Elche. EFSA unveiled its analysis and proposed limit in December 2021. BPA exposure was “a health concern … for all age groups,” the expert panel wrote. And it noted that most people consume far more BPA than allowed under the proposed limit.
EFSA is now pushing to finalize the new standard by December. EU legislators would then use it to establish legally binding limits on how much BPA is allowed to leach from packaging into food.
“If we are logical, there should be some action very quickly on BPA,” says Robert Barouki, a toxicologist at the University of Paris.
In the United States, a number of groups recently urged FDA to follow EFSA’s lead and consider new limits on BPA. Others note that people are often exposed to BPA in combination with other chemicals, which could increase the risk from low doses. For example, children of Swedish women exposed to BPA and other endocrine disrupters early in pregnancy have a higher risk of language delays, according to a study in Science this week. “This is another argument for reducing BPA,” says co-author Barbara Demeneix, an endocrinologist with the Natural History Museum in Paris.
Even if Europe adopts the new standard, public health advocates worry manufacturers will replace BPA with very similar chemicals, such as bisphenol S (BPS), that have also been linked to health effects. “We don’t want to see this assessment repeated for the BPS or BPF [bisphenol F] and need more decades of risk assessment,” says Ninja Reineke, head of science at the CHEM Trust, an advocacy group that focuses on environmental and health impacts of endocrine disruptors.
To avoid that problem, many advocates have called for regulators around the world to set limits for whole classes of related compounds, rather than consider them one by one. For now, Vandenberg says, regulators are simply playing “chemical whack-a-mole.”
AAAS, 16 February 2022