The study that called for the use of black plastic utensils had a major mathematical error

The editors of the environmental chemistry journal Chemosphere have published an eye-catching correction to a study suggesting it is toxic Flame retardants from electronic devices are in some household products made of black plasticIncluding kitchen utensils. The study raised a A flurry of media reports A few weeks ago he appealed to people urgently Get rid of their kitchen spoons And spoons. Wirecutter even offered a buying guide for What to replace it.

Correctionwhich was published on Sunday, will likely take some of the heat off the beleaguered pots. The authors made a mathematical error that excluded the estimated risks from kitchen utensils by a significant amount.

Specifically, the authors estimated that if a kitchen tool contained average levels of a major toxic flame retardant (BDE-209), the tool would transfer 34,700 nanograms of contaminants per day based on regular use during cooking and serving hot food. The authors then compared this estimate to the BDE-209 reference level that the EPA considers safe. The EPA’s safe level is 7,000 nanograms — per kilogram of body weight — per day, and researchers used 60 kilograms as an adult’s weight (about 132 pounds) for their estimate. So, the EPA safe limit would be 7,000 multiplied by 60, resulting in 420,000 nanograms per day. This is 12 times the estimated exposure of 34,700 nanograms per day.

However, the authors incorrectly set zero, stating that the EPA’s safe limit is 42,000 nanograms per day for a 60-kg adult. This error made the estimated exposure appear to be approximately at the safe limit, even though it was actually less than a tenth of the maximum.

“(W)e incorrectly calculated the reference dose for a 60-kg adult, initially estimating it as 42,000 ng/day instead of the correct value of 420,000 ng/day,” the correction said. As a result, we have revised our statement from “The calculated daily intake will approach the reference dose for BDE-209 in the United States” to “The calculated daily intake remains an order of magnitude lower than the reference dose for BDE-209 in the United States.” “.We apologize for this error and have updated it in our manuscript.”

Conclusion unchanged

While moving away from this level of volume seems like a big mistake, the authors don’t seem to think it changes anything. “This computational error does not affect the overall conclusion of the paper,” the correction stated. The corrected study still concludes by saying that flame retardants “significantly contaminate” plastic products, which have a “high exposure potential.”

Ars reached out to the lead author, Megan Liu, but did not hear back. Liu works for the environmental health advocacy group Toxic-Free Future, which led the study.

The study highlighted that flame retardants used in plastic electronics can, in some cases, be recycled and turned into household items.