Editors of the environmental chemistry journal Chemosphere responded to a study that found toxic flame retardants from electronics were found in some household items made from black plastic, such as kitchen utensils. A correction has been posted. The study sparked a flurry of media coverage a few weeks ago, with urgent calls for people to ditch kitchen spatulas and spoons. Wirecutter also provided a buying guide on what to replace it with.
The fix, posted Sunday, should provide some relief for the beleaguered cookware. The authors made a mathematical error that missed the estimated risk from kitchen appliances by an order of magnitude.
Specifically, the authors found that if kitchen utensils contain moderate levels of an important toxic flame retardant (BDE-209), based on their regular use during cooking and when serving hot food, We estimate that kitchen utensils can transfer 34,700 nanograms of contaminants per day. The authors then compared that estimate to the reference level of BDE-209, which is considered safe by the Environmental Protection Agency. The EPA’s safe level is 7,000 ng per kilogram of body weight per day, and the authors used 60 kg of adult body weight (approximately 132 pounds) as an estimate. Therefore, the safe EPA limit is 7,000 times 60, or 420,000 ng per day. This is 12 times the estimated daily exposure of 34,700ng.
However, the authors missed zero and reported the EPA’s safe limit as 42,000 ng per day for an adult weighing 60 kg. This error made the estimated exposure appear to be close to the safe limit when in fact it was less than one-tenth of the limit.
“(W)e incorrectly calculated the reference dose for an adult weighing 60 kg, initially estimating it to be 42,000 ng/day instead of the correct value of 420,000 ng/day,” the correction reads. “As a result, we have changed our statement from ‘The calculated daily intake will approach the U.S. BDE-209 reference dose’ to ‘The calculated daily intake will still be lower than the U.S. BDE-209 reference dose. We regret this error and have updated the manuscript.
unchanged conclusion
An order of magnitude off seems like a significant error, but the authors seem to think it doesn’t change anything. “This calculation error does not affect the overall conclusions of the paper,” the correction reads. The revised study still ends by stating that flame retardants “significantly contaminate” plastic products with “high potential for exposure.”
Ars contacted lead author Megan Liu, but did not receive a response. Liu works for Toxic-Free Future, an environmental health advocacy group that led the study.
The study highlighted that flame retardants used in plastic electronics could in some cases be recycled into household products.
