The editors of the environmental chemistry journal Chemosphere have published an eye-catching correction to a study reporting that toxic flame retardants from electronic devices end up in some household products made of black plastic, including kitchen utensils. The study sparked a flurry of media reports a few weeks ago urgently imploring people to ditch their spatulas and cooking spoons. Wirecutter also offered a buying guide on what to replace them with.
The fix, released Sunday, will likely take some of the heat off the beleaguered tools. The authors made a mathematical error that shifted the estimated risk from cooking utensils by an order of magnitude.
Specifically, the authors estimated that if a cooking utensil contained average levels of a toxic flame retardant (BDE-209), it would transfer 34,700 nanograms of the contaminant per day based on regular use when cooking and serving hot foods. . The authors then compared that estimate to a reference level of BDE-209 considered safe by the Environmental Protection Agency. The safe level set by the EPA is 7,000 ng, per kilogram of body weight, per day, and the authors used 60 kg as an adult weight (about 132 pounds) for their estimate. So, the EPA safety limit would be 7,000 multiplied by 60, giving you 420,000 ng per day. This is 12 times more than the estimated exposure of 34,700 ng per day.
However, the authors missed zero and reported the EPA’s safe limit as 42,000 ng per day for a 60 kg adult. The error made it appear that the estimated exposure was almost at the safe limit, even though it was actually less than a tenth of the limit.
“We 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,” the correction reads. “Accordingly, we have revised our statement from ‘the calculated daily intake would approach the US BDE-209 reference dose’ to ‘the calculated daily intake remains an order of magnitude lower than the US BDE-209 reference dose’ .’ We apologize for this error and have updated it in our manuscript.”
Conclusion unchanged
While being off by an order of magnitude seems like a significant error, the authors don’t seem to think it changes anything. “This calculation error does not affect the overall conclusion of the paper,” the correction reads. The corrected study still ends by saying that flame retardants “significantly contaminate” plastic products, which have “high potential for exposure.”
Ars reached out to the lead author, Megan Liu, but did not receive a response. Liu works for the environmental health advocacy group Toxic-Free Future, which conducted the study.
The study highlighted that flame retardants used in plastic electronic components can, in some cases, be recycled into household items.