Recent panic over black plastic started with a math error

BDE-209 is still bad for you.
Modern Kitchen with wooden table, kitchen utensils, cooking pots and others, white background.
Initial BDE-209 estimates were 12 times higher than the actual number. Credit: Deposit Photos

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The authors of a study warning against health risks associated with a common plastic found in kitchen utensils and children’s toys have issued a major correction to their report. According to their December 16th announcement, researchers at the environmental health advocacy group, Toxic-Free Future, initially believed people are potentially exposed to decabromodiphenyl ether on a daily basis as much as 12 times more than they actually are. But, as the authors cautioned, even the vastly reduced measurement doesn’t change the fact that people shouldn’t be ingesting flame-retardants.

First commercialized in the 1970s, decabromodiphenyl ether (also known as BDE-209 or deca-BDE) quickly became a popular bromine-based flame-retardant plastic used in goods like TV and computer cases. Over time, however, research linked it to a host of health issues including cancer , reproductive problems, endocrine disruption, and neurological issues. Companies have since replaced BDE-209 with (possibly also hazardous) alternatives, while the European Union, China, and at least two US states have issued bans on the material.

[ Related: How to make stainless steel pans nonstick. ]

The industry shift away from BDE-209 hasn’t stopped it from still sometimes entering households, however. As Toxic-Free Future’s study originally published in Chemosphere’s October 2024 issue notes, microscopic amounts of recycled black plastic containing the compound are sometimes detectable in common products like spatulas, shipping packaging, and even children’s toys.

“Companies continue to use toxic flame retardants in plastic electronics, and that’s resulting in unexpected and unnecessary toxic exposures,” added study lead author, Megan Liu, in an accompanying announcement at the time. “These cancer-causing chemicals shouldn’t be used to begin with, but with recycling, they are entering our environment and our homes in more ways than one. The high levels we found are concerning.”

Those levels, according to Liu and her colleagues, were initially estimated to be shockingly higher than the Environmental Protection Agency’s safety regulation. The authors offered a kitchen utensil as an example, which they calculated could transfer upwards of 34,700 nanograms of BDE-209 onto food per day. Given the EPA’s 7,000 ng-per-kilogram of body weight, researchers explained that a hypothetical 60 kg (roughly 132 lbs) adult could receive as much as 12 times the recommended limit each day.

Major outlets such as Huffpost, CNN, and The Washington Post subsequently highlighted the troubling conclusions. But on Sunday, Toxic-Free Future researchers issued a correction: Basically, they missed a zero in their math.

“[W]e miscalculated the reference dose for a 60 kg adult, initially estimating it at 42,000 ng/day instead of the correct value of 420,000 ng/day,” they explained. “As a result, we revised our statement from ‘the calculated daily intake would approach the U.S. BDE-209 reference dose’ to ‘the calculated daily intake remains an order of magnitude lower than the U.S. BDE-209 reference dose.’ We regret this error and have updated it in our manuscript.”

As Ars Technica adds, the study has always maintained the probability of exposure to BDE-209 through everyday household products remains comparatively low. Of the 203 items analyzed for the report, only about 10 percent of them contained levels of bromine-based flame retardants. More specifically, just 14 of the 203 products directly contained BDE-209. But as the authors explained in their correction, any amount is arguably too much for you.

“This calculation error does not affect the overall conclusion of the paper,” Liu’s team warns.

“These cancer-causing chemicals shouldn’t be used to begin with, but with recycling, they are entering our environment and our homes in more ways than one,” Toxic-Free Future’s October announcement read. “The high levels we found are concerning.”

So while those “high levels” may not be nearly as high as first believed, it’s safe to say that the less bromine-laced plastic in your body, the better.

 

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