The study calling for black plastic tools had a major math error

The editors of the environmental chemistry journal Chemosphere have published a striking correction to a study reporting toxics Electronic flame retardants are included in some household products made of black plastickitchen utensils included. The study sparked a a bunch of media reports that a few weeks ago he made an urgent plea to the people remove the kitchen spatulas and spoons Wirecutter also offered a buying guide what to replace it with.

correctionposted on sunday will probably take some heat off the covered gear. The authors made a math error that off-sets the estimated risk of cookware by an order of magnitude.

Specifically, the authors estimated that if a kitchen appliance contained moderate levels of a toxic flame retardant (BDE-209), the appliance would transfer 34,700 nanograms of the pollutant per day based on typical use in cooking and serving hot food. The authors then compared this estimate to the reference level of BDE-209, which is considered safe by the Environmental Protection Agency. The safe level of EPA is 7,000 ng—per kilogram of body weight—per day, and the authors used 60 kg as an adult’s weight (about 132 pounds) for their estimate. So the safe EPA limit would be 7,000 times 60, giving 420,000 ng per day. This is 12 times the daily exposure of 34,700 ng.

However, the authors missed a zero and reported that the EPA’s safe limit is 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 one-tenth of the limit.

“(E) miscalculated the reference dose for a 60-kg adult, initially using a value of 42,000 ng/day instead of the correct value of 42,000 ng/day,” the correction reads. “Consequently, we revised our statement ‘estimated daily intake would approach the US BDE-209 reference dose’ to ‘estimated daily intake remains an order of magnitude lower than the US BDE-209 reference dose’. We regret this error and have updated it in our manuscript. we have”.

Unchanged conclusion

While being disabled by an order of magnitude seems like a significant error, the authors don’t think it changes anything. “This miscalculation does not affect the overall conclusion of the paper,” the correction reads. The peer review still concludes 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 into household items.