You may have run across one of many, many stories recently about a report stating that black plastic kitchen utensils such as spatulas are a health concern.
The study released by Toxic-Free Future in October got prominent play in publications such as The Washington Post, The New York Times, The Los Angeles Times and NPR, with warnings that consumers should immediately throw out black plastic utensils because they could leach dangerous chemicals into our food. The report focused on flame retardants that are used in black plastics for electronics which then also end up in kitchenware.
Here's the problem: That study had faulty math.
Yes, black plastic can leach chemicals during the cooking process — the report cited a potential intake of 34,700 nanograms per day of the chemical decabromodiphenyl ether, or BDE-209, which is about 80 percent of the maximum safe level of 42,000 nanograms per day. That number is based on a "safe" ingestion level of 7,000 nanograms per kilogram of body weight per day, based on an average body weight of 60 kilograms.
"Did you catch that?" a blog from Columbia University statistical modeling specialists noted. "That sounds bad, but 60 times 7,000 is not 42,000. It is 420,000."
Which means, as McGill University's Joe Schwarcz noted, the numbers cited by Toxic-Free Future were only a 10th of the levels that prompted all those reports.
"For me, this risk would not be enough to discard a black plastic kitchen item if I had one," Schwarcz wrote. "… That being said, there should be no flame retardants in such items."
The National Post in Canada has more information and reaction here.