Oops! The health controversy about using black plastics got interesting

After realizing the math error 🧮 that made black plastics sound 10x worse ☠️, a correction was published ✅, the publisher lost its credibility and indexing 😬, and the blown-out-of-proportion scare just won’t go away 🤯.

But . . .

Let’s not lose sight that brominated flame retardants (BFRs) and organophosphate flame retardants (OPFRs) are not essential nutrients nor healthy ingredients, so even if they’re not going to wreak havoc on our health like the study first (incorrectly) implied, we probably should reduce our exposures.

If clients, followers, friends, and family have been wondering about the “toxic black plastic” health controversy in the news lately, here’s the scoop (with a bunch of receipts/references included at the end).

In a nutshell:

• A recent study found toxic flame retardants contaminating some black plastic kitchen items and toys. A simple math error was caught in that study after it was published and the press release went out. The error was corrected to confirm that these black plastic items are not nearly as bad as was initially stated (10x less bad).
• Are there healthier options other than black plastic when it comes to food storage and preparation? Yes, absolutely.
• Do we need to eliminate and replace all black plastic items immediately because they’re the #1 cause of everyone’s health problems? Not necessarily, but reducing plastic use is probably a good idea for yours and the planet’s health.
• Moral of the story: When one single study finds something that seems exceptionally terrifying or sensational . . . it probably should be verified to see how solid the findings are. They might be rock-solid, totally flimsy, or somewhere in between. More studies and better studies can figure that out.

Here’s what happened step-by-step . . .

Step 1 – The story started with a research study funded by “Toxic-free future” (a U.S.-based environmental health and advocacy group)

Here are some of the headlines that initially circulated after the study was published in late 2024:

• “First-ever study finds cancer-causing chemicals in black plastic food-contact items sold in the U.S.” (Toxic-free future* the organization paying for and sponsoring the study)
• “There’s A Scary Rumor About Black Plastic Cookware — Should You Throw Yours Out?” (HuffPost)

Step 2 – A simple math error was found after the study was published in a peer-reviewed journal and the press release went out

After the study was published and the media and social media frenzy started, a very simple math error was detected (literally multiplying by 10). This math error was acknowledged by the authors and publishers and they eventually posted a correction.  In the meantime, these stories circulated about how the black plastic containers and utensils were not healthy and did contain the toxins, but we now know that the toxicity levels were 10x less than the study initially reported. (Does this mean the toxicity is zero? Absolutely not. It’s now much less alarming and urgent, even though there still is some risk.)

• Are Black Plastic Spatulas and Serving Spoons Safe to Use? (McGill Office of Science and Society and the Montreal Gazette)
• How a simple math error sparked a panic about black plastic kitchen utensils (National Post)
• “How a simple math error sparked a panic about black plastic kitchen utensils”: Does it matter when an estimate is off by a factor of 10? (Columbia University Statistical Modeling, Causal Inference, and Social Science)
• Your black plastic kitchen utensils aren’t so toxic after all. But you should still toss them, group says (Los Angeles Times)
• Error in viral black plastic spatula study results in ten-fold overestimation of risk (RNZ)

Step 3 – This is just one example of the error-prone and low-quality studies published by that journal, so it has been de-indexed

How does a simple math error make it through the scientists doing the study and rigorous review by their peers?

The error was found (albeit later than it should have been found) and a correction was acknowledged and published, which is what any reputable scientist and publisher would do. However it’s not the first time the journal (Chemosphere) has published low-quality work. Eight (yes 8!) studies were retracted from the journal in a month and dozens of “expressions of concern” were submitted. This shows that the journal has not met acceptable levels of scientific integrity and quality, and it has been deindexed. Deindexed means that the journal is no longer considered to be credible.

• Journal that published faulty black plastic study removed from science index (ARS Technica)

The journal acknowledged the concerns and published the steps they’re taking to ensure higher standards of research integrity:

• Discover the decisive steps we are taking to ensure research integrity (Chemosphere Science Direct)

Step 4 – The original, incorrectly overly scary results are still being shared, so not everyone is aware of the corrected information

It seems that the initial frenzy to “immediately throw out all of your black plastic because it is causing all of your health issues . . . and ignore the reasonable, mathematical update” is another example of a famous quote, “A lie can travel halfway around the world before the truth puts on its shoes.”

• ‘Zombie facts’ live on after black plastic and other studies get corrected or retracted (CBC)
• How fake news is spread (Leesa Klich)

Now that we know *what* happened . . . *how* did this happen?

A deeper dive into what the study originally found about the amounts of toxic flame retardants in common black plastic household items

Most flame retardants (excluding water) are not healthy for people to ingest. At certain levels they have been linked to cancers, hormonal disruptions, neurotoxicity, and reproductive concerns. These toxic effects are why some (but not all) of these compounds have been phased out of use, for the most part. Certain flame retardants are still used in electrical and electronic equipment, like TVs and computers, but those items can catch fire and we don’t eat them, so the risk to health is very small.

The problem is that these compounds are very stable, persistent chemicals (they don’t break down easily), so small amounts are found in air, dust, water, and can eventually make their way into marine animals, birds’ eggs, and even human blood, breast milk, and placentas.

If no animals or people eat electronics, how are they getting into animals and people?

Small amounts can unintentionally end up where we don’t want them. One way is from the recycling of electronic waste where some of the dust and/or bits of those plastics treated with the compounds can end up in plastics being used to make black sushi trays, plastic takeout containers, kitchen utensils, toys, etc. This is how they can lead to being ingested and potentially causing harm.

Toxic-free future’s own scientists led this study that confirmed that, yes, small amounts of flame retardants are detected in black plastic kitchenware available in the U.S. In other words, more than zero can be found. So, even though these toxic compounds are not supposed to be there, they are there in tiny amounts as contaminants.

How was the study—and mathematical statistics—done that led to the initial conclusion that was off by a factor of 10?

Toxic-free future’s researchers bought 203 black plastic items they found online and around Seattle so they can be tested. Table 2 in the study shows that the highest levels of bromium (from brominated flame retardants) were found in sushi trays, followed by a toy car, a peeler, a travel checkers set, pirate coin medallion beads, and a slotted spoon.

When the researchers calculated the dose of one of the brominated flame retardants called BDE (decabromodiphenylether), they made a simple error. They knew the reference dose (daily dose that likely won’t harm human health) was 7,000 ng/kg bw/day. To turn a kg into an average person, you need to know that an average person weighs 60 kg. So, that dose of 7,000 ng per kg body weight per day is the same as 420,000 ng/day for a 60 kg adult (7,000 x 60 = 420,000). Unfortunately though, they missed a zero and then based their results as though the reference dose was 42,000 ng/day per person, when in fact it is 420,000 ng/day per person.

Honestly, this should have been caught by the researchers themselves before they submitted their study. And failing that, it should have been caught by a peer reviewer (another scientist who scrutinizes studies in their area of expertise) before being published in the journal.

Because a simple math mistake got through all of those layers of review that are supposed to ensure that only high-quality studies are published, it called into question the quality and rigour that the journal Chemosphere really uses before publishing research.

Here’s the statement from the researchers regarding their error and correction

• Corrigendum to ‘From e-waste to living space: Flame retardants contaminating household items add to concern about plastic recycling’ [Chemosphere 365 (2024) 143319]

Here’s the statement from the journal Chemosphere who published the study, acknowledging concerns about the lack of integrity and quality of several studies they’ve published

• Discover the decisive steps we are taking to ensure research integrity (Chemosphere Science Direct)

Should black plastic food containers, cutlery, and toys be replaced?

Sure. If you want to and have the means to throw things out and replace them with stainless steel, wood, or something better, go ahead. You will probably reduce your very small exposure to these flame retardants.

Signing off and toasting: To raising the bar for research study quality and looking a bit deeper into sensationalized headlines!

Over to you

Have you seen and shared the news? What about the correction? What are you planning to do with your black plastic cutlery and food containers? (Spoiler alert: As of today, I threw out one black plastic slotted spoon, but not all of my black plastic utensils.)

Do you have another great resource that I missed? Post the link in the comments below!

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References

Brean, J. (2024, December 11). How a simple math error sparked a panic about black plastic kitchen utensils. National Post. https://nationalpost.com/news/canada/black-plastic

Chemosphere. (2024, December 12).  Discover the decisive steps we are taking to ensure research integrity. https://www.sciencedirect.com/journal/chemosphere/about/news/discover-the-decisive-steps-we-are-taking-to-ensure-research-integrity

Emhail, I. (2024, December 30). Error in viral black plastic spatula study results in ten-fold overestimation of risk. RNZ. https://www.rnz.co.nz/news/national/537870/error-in-viral-black-plastic-spatula-study-results-in-ten-fold-overestimation-of-risk

Garcia, K. (2024, December 19). Your black plastic kitchen utensils aren’t so toxic after all. But you should still toss them, group says. LA Times. https://www.latimes.com/california/story/2024-12-19/recycled-black-plastic-utensils-study-miscalculated

Gelman, A. (2024, December 13). “How a simple math error sparked a panic about black plastic kitchen utensils”: Does it matter when an estimate is off by a factor of 10? Statistical Modeling, Causal Inference, and Social Science. https://statmodeling.stat.columbia.edu/2024/12/13/how-a-simple-math-error-sparked-a-panic-about-black-plastic-kitchen-utensils/

Liu, M., Brandsma, S. H., & Schreder, E. (2024). From e-waste to living space: Flame retardants contaminating household items add to concern about plastic recycling. Chemosphere, 365, 143319. https://doi.org/10.1016/j.chemosphere.2024.143319
https://pubmed.ncbi.nlm.nih.gov/39271080/
https://www.sciencedirect.com/science/article/abs/pii/S0045653524022173
https://www.sciencedirect.com/science/article/pii/S0045653524022173?via%3Dihub

Liu, M., Brandsma, S. H., & Schreder, E. (2024). Corrigendum to ‘From e-waste to living space: Flame retardants contaminating household items add to concern about plastic recycling’ [Chemosphere 365 (2024) 143319]. Chemosphere, 143903. Advance online publication. https://doi.org/10.1016/j.chemosphere.2024.143903
https://pubmed.ncbi.nlm.nih.gov/39675991/
https://www.sciencedirect.com/science/article/pii/S004565352402811X?via%3Dihub

Mole, B. (2024, December 19). Journal that published faulty black plastic study removed from science index. ARS Technica. https://arstechnica.com/health/2024/12/journal-that-published-faulty-black-plastic-study-removed-from-science-index/

Schwarz, J. (2024, December 6). Are Black Plastic Spatulas and Serving Spoons Safe to Use? McGill Office for Science and Society. https://www.mcgill.ca/oss/article/critical-thinking-health-and-nutrition/are-black-plastic-spatulas-and-serving-spoons-safe-use

ScienceDirect. (n.d.). Reference dose. https://www.sciencedirect.com/topics/medicine-and-dentistry/reference-dose

Science Up First. (2024, August 14). The dose makes the poison. https://scienceupfirst.com/misinformation-101/the-dose-makes-the-poison/

Stohler, S. (2024, October 1). First-ever study finds cancer-causing chemicals in black plastic food-contact items sold in the U.S. Toxic Free Future. https://toxicfreefuture.org/press-room/first-ever-study-finds-cancer-causing-chemicals-in-black-plastic-food-contact-items-sold-in-the-u-s/

Wilson, J. (2024, December 8). There’s A Scary Rumor About Black Plastic Cookware — Should You Throw Yours Out? HuffPost. https://www.huffpost.com/entry/theres-a-scary-rumor-about-black-plastic-cookware-should-you-throw-yours-out-ano_l_6751e1fde4b0a7189dd89bc1

Zafar, A. (2025, January 11). ‘Zombie facts’ live on after black plastic and other studies get corrected or retracted. CBC News. https://www.cbc.ca/news/health/corrections-retractions-1.7428260

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