HomeThe World We DiscoverA Missing Zero Inflated the Black Spatula Panic

A Missing Zero Inflated the Black Spatula Panic

Flame retardants from recycled electronics do contaminate black plastic kitchen items. A math error made the risk seem ten times worse than it was.

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The World We Discover · Explore this series
December 23, 2024
Key Takeaways
  • A calculation error made black spatula flame retardant exposure seem ten times worse than it was.
  • Corrected data puts estimated daily exposure at roughly 8% of the EPA safety limit.
  • Flame retardants from recycled electronics genuinely do appear in black plastic items.

Megan Liu was testing black plastic spatulas for flame retardants when her team's calculations sparked a nationwide kitchen cleanout.

The numbers looked alarming. Media outlets ran headlines urging readers to throw out their utensils. Then someone checked the math.

The study, published in Chemosphere in September 2024, had found something genuinely troubling: flame retardants from recycled electronics turning up in household items that touch food.

But a calculation error inflated the apparent health risk by a factor of ten.

Key figure

18,600 ppm

Bromine compounds found in the worst-contaminated item – 1,860 times the EU limit of 10 ppm

E-Waste in the Utensil Drawer

Liu, a science and policy manager at advocacy group Toxic-Free Future, worked with analytical chemist Sicco Brandsma at Vrije Universiteit Amsterdam to test 203 black plastic items.

Twenty showed elevated bromine levels. Of those, 17 contained brominated flame retardants at concentrations far exceeding European limits.

The worst offender was a sushi takeout tray containing 18,600 parts per million of bromine-based compounds. The EU limit stands at 10 ppm.

Black plastics absorb this contamination readily because electronics manufacturers favor dark-colored cases, and recyclers struggle to separate them from cleaner materials.

A Misplaced Zero Changes Everything

The study estimated that cooking with contaminated utensils could deliver 34,700 nanograms of BDE-209 daily.

What is BDE-209?

Decabromodiphenyl ether, known as BDE-209 or deca-BDE, is a flame retardant once widely used in television casings and computer housings. The EPA banned it in 2021 after studies linked it to cancer, reproductive problems, and neurological effects. When electronics containing this chemical get recycled, the contaminated plastic can end up in new products.

The authors compared this to what they calculated as the EPA's safe limit: 42,000 nanograms per day for a 60-kilogram adult. At roughly 80 percent of that threshold, the exposure seemed genuinely concerning.

The actual EPA reference dose is 420,000 nanograms per day. A missing zero. Instead of approaching the safety limit, the estimated exposure sat at about 8 percent of it.

Chemosphere published a correction in December 2024. A second correction followed in July 2025 after critics identified additional methodological problems.

Mark Jones, an industrial chemist who spent his career at Dow Chemical, noted that the researchers had tested only the handles of kitchen utensils.

A steel spatula with a plastic grip would yield the same exposure estimate despite being incapable of transferring flame retardants to food. His analysis suggested the actual exposure through cooking approaches zero.

What Remains After the Correction

Liu described the error as a typo and maintained that her conclusions stood. "The levels of flame retardants that we found in black plastic household items are still of high concern," she said in a statement to The National Post (paywalled).

Stuart Harrad, an environmental chemist at the University of Birmingham, agreed the findings were "perfectly plausible" despite the calculation problem.

I think it does change the flavour of the whole thing somewhat when you're off by a factor of ten.

Joe Schwarcz, McGill University's Office for Science and Society, who found the error

The underlying discovery that banned chemicals are entering household products through recycling remains valid. Several European countries are now examining whether black plastics should be excluded from food packaging entirely.

The episode illustrates the gap between scientific findings and public health recommendations. Flame retardants do appear in recycled black plastic. That contamination does exceed regulatory limits set by the European Union.

Whether cooking with these utensils poses meaningful risk to human health is a different question, one the corrected data cannot confidently answer.

Washington state's ban on organohalogen flame retardants in electronics enclosures took effect in January 2025.

If fewer toxic additives enter the recycling stream, fewer will emerge in spatulas. The math error did not change that logic.

It merely made the conversation louder than the evidence warranted.


Sources

Fact Check: Claim-by-Claim Verification Verified

The recap closely matches the original study, its corrections, and expert commentary, and it treats remaining risk and regulatory questions with appropriate caution.

1 Verified
The Chemosphere paper by Liu, Brandsma, and Schreder on flame retardants in black plastic household items and e-waste recycling is correctly identified and dated to 2024
2 Verified
The article accurately reports that a dose‑calculation error in the original paper overstated BDE‑209 intake by a factor of ten relative to the EPA oral reference dose, and that Chemosphere issued corrections in late 2024 and mid‑2025

Commentary

  • The recap slightly simplifies the exposure math by framing it as a “missing zero,” whereas subsequent expert critique suggests the corrected intake from utensils is hundreds of times lower than typical background exposure, making “approaches zero” a qualitative judgment rather than a quantified result.

Sources used for verification

Academic/Peer-reviewed:

Other reliable sources:

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