The Study That Called Out Black Plastic Utensils Had a Major Math Error

Editors of the environmental chemistry journal Chemosphere have issued a dramatic correction to a study reporting toxic substances Flame retardants in electronics are found in some household products made of black plasticincluding kitchen utensils. This research triggered The media has reported A few weeks ago, an urgent plea was made to people throw away their kitchen spatula and spoon. Wirecutter even offers a buying guide what to replace them with.

correctSunday’s announcement could cool things off for the beleaguered appliance. The authors made a mathematical error that lowered the estimated risk of kitchen appliances by an order of magnitude.

Specifically, the authors estimate that a kitchen utensil containing moderate levels of a major toxic flame retardant (BDE-209) could transfer 34,700 nanograms of contamination per day based on routine use when cooking and serving hot food. things. The authors then compared that estimate to reference levels of BDE-209 considered safe by the Environmental Protection Agency. The EPA safety level is 7,000 nanograms per kilogram of body weight per day, and the authors used 60 kilograms as an adult weight (approximately 132 pounds) for their estimate. Therefore, the EPA’s safety limit is 7,000 times 60, which results in 420,000 nanograms per day. This is 12 times higher than the estimated exposure of 34,700 nanograms per day.

However, the authors missed a zero and reported the EPA’s safety limit to be 42,000 nanograms per day for a 60-kg adult. This error makes the estimated exposure appear to be close to the safe limit, even though it is actually less than one-tenth of the limit.

“We incorrectly calculated the reference dose for a 60-kg adult, originally estimated to be 42,000 ng/day, rather than the correct value of 420,000 ng/day,” the correction reads. “Accordingly, we are revising the statement from ‘The calculated daily intake will be close to the U.S. reference dose for BDE-209’ to ‘The calculated daily intake will still be an order of magnitude below the U.S. reference dose for BDE-209.'” We regret this error and have updated it in our manuscript.

The conclusion remains unchanged

While deviating 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 findings still indicate that flame retardants “significantly contaminate” plastic products with “high exposure potential.”

Ars has reached out to lead author Megan Liu but has not yet received a response. Liu works for the environmental health advocacy group Toxic-Free Futures, which led the study.

Research highlights that flame retardants used in plastic electronics may in some cases be recycled into household products.