Huge Math Error Corrected In Black Plastic Study (arstechnica.com) 105
Ars Technica's Beth Mole reports: Editors of the environmental chemistry journal Chemosphere have posted an eye-catching correction to a study reporting toxic flame retardants from electronics wind up in some household products made of black plastic, including kitchen utensils. The study sparked a flurry of media reports a few weeks ago that urgently implored people to ditch their kitchen spatulas and spoons. Wirecutter even offered a buying guide for what to replace them with. The correction, posted Sunday, will likely take some heat off the beleaguered utensils. The authors made a math error that put the estimated risk from kitchen utensils off by an order of magnitude.
Specifically, the authors estimated that if a kitchen utensil contained middling levels of a key toxic flame retardant (BDE-209), the utensil would transfer 34,700 nanograms of the contaminant a day based on regular use while cooking and serving hot food. The authors then compared that estimate to a reference level of BDE-209 considered safe by the Environmental Protection Agency. The EPA's safe level is 7,000 ng -- per kilogram of body weight -- per day, and the authors used 60 kg as the adult weight (about 132 pounds) for their estimate. So, the safe EPA limit would be 7,000 multiplied by 60, yielding 420,000 ng per day. That's 12 times more than the estimated exposure of 34,700 ng per day. However, the authors missed a zero and reported the EPA's safe limit as 42,000 ng per day for a 60 kg adult. The error made it seem like the estimated exposure was nearly at the safe limit, even though it was actually less than a tenth of the limit. "We regret this error and have updated it in our manuscript," the authors said in a correction.
"This calculation error does not affect the overall conclusion of the paper," the correction reads. The study maintains that flame retardants "significantly contaminate" the plastic products, which have "high exposure potential."
Specifically, the authors estimated that if a kitchen utensil contained middling levels of a key toxic flame retardant (BDE-209), the utensil would transfer 34,700 nanograms of the contaminant a day based on regular use while cooking and serving hot food. The authors then compared that estimate to a reference level of BDE-209 considered safe by the Environmental Protection Agency. The EPA's safe level is 7,000 ng -- per kilogram of body weight -- per day, and the authors used 60 kg as the adult weight (about 132 pounds) for their estimate. So, the safe EPA limit would be 7,000 multiplied by 60, yielding 420,000 ng per day. That's 12 times more than the estimated exposure of 34,700 ng per day. However, the authors missed a zero and reported the EPA's safe limit as 42,000 ng per day for a 60 kg adult. The error made it seem like the estimated exposure was nearly at the safe limit, even though it was actually less than a tenth of the limit. "We regret this error and have updated it in our manuscript," the authors said in a correction.
"This calculation error does not affect the overall conclusion of the paper," the correction reads. The study maintains that flame retardants "significantly contaminate" the plastic products, which have "high exposure potential."
Good. Science works. (Score:5, Informative)
(Slashdot editors take note.)
It would be a sign of their doing actual science if a few psychology papers were corrected sometimes.
Good Questions. (Score:3)
Speaking of actual science, I’d love to see how the FDA determined “safe” limits for ingesting flame retardant on a daily basis, and how often that is re-evaluated. Preferably before the expected class-action against flame retardants happens because of a math “error” that carved out billions in profit for decades while killing millions prematurely.
Sorry for my obvious skepticism, but class-actions like this have practically become an American tradition. I’d prefer to ma
Re: (Score:2)
*EPA not FDA. (Or perhaps it should be both.)
Re: (Score:3)
Re: (Score:1)
1) Consult with industry regarding their practices, the extent of their desire to change and the associated cost.
2) Accept donations as votes for particular 'safe levels' in the final report
3) Publish report
Did I win?
I think this youtuber (Adam Ragusea) told them. (Score:5, Interesting)
Re: (Score:2, Troll)
You really have it out for the slashdot editors huh? Show us where they touched you.
Re: (Score:1)
Oh I get it, you bought into the Elon Musk DO(UCH)E BS? How much money do you think this site makes? What you're doing is, essentially, yelling at volunteers handing you a meal in a soup kitchen. Unless you're a company like SpaceX which has the luxury of people lining up to work there, the strategy of "beat your employees until their morale improves" may not work for you. Not unless you want your business to fail spectacularly as nobody will want to work for you, as is their prerogative. This is like a bil
Yes....but... (Score:2)
What is more concerning though is the claim that "This calculation error does not affect the overall conclusion of t
Re: (Score:2, Insightful)
Actually it was the unfounded misinformation that was frowned on in those days. And rightfully so. I'll take an expert making an honest mistake and publicly correcting it over a charlatan pretending to know something but literally just making up whatever people might want to hear, any day.
Error of an order of magnitude (Score:5, Insightful)
When such a big error is made, and the results indicate something that your employers (environmental health advocacy group Toxic-Free Future) may disagree with, and you claim that it does not change the conclusions, I think something smells.
Re: Error of an order of magnitude (Score:2)
Re:Error of an order of magnitude (Score:5, Insightful)
Summary: The conclusions are unaffected because they did not use this number to draw conclusions.
1) The mistake, while big, was also exceptionally easy to spot and correct, due to their very explicit presentation of the multiplication. Anyone could find the mistake my just knowing 6x7=42 and finding out the missing zero (and indeed a youtuber foud it). The affected paragraph (my emphasis):
This compares to a BDE intake in the U.S. of about 250 ng/day from home dust ingestion and about 50 ng/day from food (Besis and Samara, 2012) and would approach the U.S. BDE-209 reference dose of 7000 ng/kg bw/day (42,000 ng/day for a 60 kg adult) (United States Environmental Protection Agency, 2008).
2) Their affected sentence "would approach the dose" is still correct to 1/10 of the exposure limit. 1/10 of limit is also a "significant" amount as they say.
3) They do nothing with the value. They don't use this value to claim some items in particular are dangerous, or that we should prohibit something. They say the amounts are significant and regulatory agencies should look into it. Both are correct in either case. Here are the conclusions:
These results show that when toxic additives are used in plastic, they can significantly contaminate products, made with recycled content, that do not require flame retardancy. Products found in this study to contain hazardous flame retardants included items with high exposure potential, including food-contact items as well as toys. Regulatory bodies have begun to address the use of certain classes of flame retardants (The New York State Senate, 2021; Washington State Department of Ecology, 2022), but more regulation is needed to end the use of hazardous additives and ensure that replacements are made with safer materials and chemicals.
Re: (Score:3)
I correct myself, as they suggest to replace something with safer materials, they do advocate to somehow prohibit something as a result of their measurements.
But still 1/10 of exposure limit is a significant value that indeed "approaches" the problematic level. For example I don't want leaded paint leakage in drinking water, even if the lead amount is 1/10 of lead exposure limit. I'd want it to be thousands or millions of times smaller than the exposure limit. If you told me lead in my drinking water is 1/1
Re: (Score:1)
pretty much.
Re: Error of an order of magnitude (Score:2)
I haven't read the study. But my understanding is that this calculation is essentially per item. I do have (and use regularly) both a black plastic spatula and a black plastic spoon. And I use both on the same meal regularly (even though not every day). My understanding is that this would put me at about 20% of daily limit. For something that is innocuous, that is concerning still.
I would not be surpised if some people use entire sets of black plastic cooking utensils.
Re: (Score:2)
Speeding and toxic chemicals aren't the same. If you speed by 2mph every day you don't wind up exceeding the speed limit by 60mph by the end of the month. However, with chemical exposure, risk can accumulate over time. The FDA levels are just set to kill people at an acceptable rate. You are always better off having less exposure, so all other things being equal, it's preferable to avoid if possible, even if a certain level is GRAS.
Re: (Score:2)
Speeding by 2 mph wasn't the example, the example was going 2 mph in a 20 zone, that is, 10% of the accepted "reasonable" limit. And that "reasonable" limit comes from the reason of various panels of experts over time. There is some subjectivity, and differing levels of risk tolerance by people who live on the street in question. Then someone (GP above) comes along and says "if X is a valid limit then (0.1)X is a valid limit" and some of us naturally wonder how many times you intend to apply that rule in succession (the limits already tend to have conservative buffers).
Not a perfect analogy but there's actually a lot here that's comparable.
You may be right that you're better off having less exposure (at least not worst), but it's not clear by how much, and it's not clear if it's worth the cost. There is always a cost, often an unexpected cost (the driving example above hinted at a few examples of unexpected costs). There are also opportunity costs. Regulation and Outrage are two useful but limited resources in the world we live in.
Why are you comparing speed limits to stuff you put in your body? Speed limits are usually set by some method like 85th percentile of traffic speed before the signs are put up. Of course some people feel comfortable driving at and over that limit, duh, that was how they set it.
EPA limits are set by what standard? Is it the 85% percentile of what was already detected in people's systems? Is it the threshold where 85% of people survived the dose? The median dosage that people thought it tasted ok with chocola
Re: (Score:2)
Re: (Score:2)
The FDA levels are just set to kill people at an acceptable rate. You are always better off having less exposure
I suppose that's a valid way to look at it, just as speed limits in school zones are set to limit deaths of school children to an acceptable rate, not zero. The way to get zero deaths of children due to automobiles in school zones would be to ban automobiles (or children) from the streets near schools *entirely*, and then enforce that limit relentlessly and absolutely.
We don't do that, because of various cost/benefit analyses (some formal, others rather unconscious) that many people have done over the year
Conclusion Clearly Different (Score:2)
Their affected sentence "would approach the dose" is still correct to 1/10 of the exposure limit. 1/10 of limit is also a "significant" amount as they say.
Sorry but less that a tenth of a dose is not an amount that is "approaching the dose" any more than 10 cents is an amount approaching a dollar. They would never have written the conclusion that way had they spotted their error before publication and, if they had, any competent referee would have complained that the wording was inconsistent with what the data showed.
Re: (Score:2)
and you claim that it does not change the conclusions, I think something smells.
Not everything is a conspiracy. If I decide to punch you in the nose instead of shooting you in the leg would you change the conclusion of "you are in pain" simply because the pain is lower?
The conclusion of the study stands based on the observations, even after the correction. Flame retardants contaminate the plastic and have a potential for exposure. The fact that the exposure potential isn't right up against the EPA safe limit doesn't change the fact that there's potential for exposure.
Re: (Score:2)
Re: (Score:2)
When such a big error is made, and the results indicate something that your employers (environmental health advocacy group Toxic-Free Future) may disagree with, and you claim that it does not change the conclusions, I think something smells.
The error was in the EPA limit they quoted, in what way does that affect their results?
60 kg adult? (Score:5, Funny)
Obviously these weren't American scientists...
Re: (Score:2)
Re: (Score:2)
Re: 60 kg adult? (Score:2)
According to the CDC, 60 kg puts you at about 20petcentile for women and about 7 percentile for men. For these kinds of study, it makes sense to pick a human on the smaller size of the curve without being uncommonly small.
https://www.cdc.gov/nchs/fasta... [cdc.gov]
I don't know the standard in the field. But basing number on about 15 percentile human in the US does not seem unreasonnable.
"The error doesn't affect our conclusion" (Score:3, Informative)
Except it absolutely does. The original conclusion was that using black plastic cooking utensils could potentially expose you to a nearly unsafe amount of BDE-209 and that this was a cause for concern. With the math error corrected though, it turns out black plastic cooking utensils don't even remotely expose you to unsafe amounts of BDE-209, and are thus in all likelihood as safe for use as any other utensil. Kudos to the authors for noticing and correcting the error, but they should have gone the distance and admitted that their error made the fundamental thesis of the paper incorrect.
Re: "The error doesn't affect our conclusion" (Score:1, Troll)
Re: (Score:2)
That EPA limit is per day.
Re: (Score:2)
--also, turns out that when they investigated actual black plastic objects, the only one that had BDE-209 even approaching limits was.. a sushi tray.
Re: (Score:2)
Cooking with a black plastic utensil for 10 days will expose you to the annual limit.... That seems very concerning. Not as bad as hitting that limit in one day, but hardly comforting.
It's the daily limit, not the annual limit. So you've taken the original "order of magnitude" error and turned it into more than two orders of magnitude. Good show.
Re: (Score:2)
Except it absolutely does. The original conclusion was that using black plastic cooking utensils could potentially expose you to a nearly unsafe amount of BDE-209 and that this was a cause for concern.
You made up your own conclusion and complained that *your* conclusion was inaccurate. Not theirs. Their conclusion was that the exposure is considered one of the primary exposure sources in the home (which it still is). Their conclusion is that there was "expected" exposure in the household (which there still is). Their conclusion hasn't changed. You can go read it in its original glory.
but they should have gone the distance and admitted that their error made the fundamental thesis of the paper incorrect.
The fundamental thesis of their paper was to check
"the presence of FRs in plastic household items on
the U.S. market, parti
Re: (Score:2)
The fact that merely cooking dinner exposes to 10% I do think supports that it exposes you to a significant amount and warrants looking into it overall.
It only takes 10 10%s a day to get there. Breakfast and dinner may get one to ~20% alone.
It definitely isn't as bad as the report first indicated, but if one is truly getting 10% here and there (I'm not reading the actual study) it seems pretty reasonable to doo some broader research and see how much the average exposure from sources like this is per a day
Or there's the other option. (Score:1)
You know what exposes me to zero flame retarding chemicals? Metal and wooden utensils.
I feel like ingesting any of those chemicals isn't worth it. Maybe we shouldn't?
Re: (Score:2, Informative)
Wooden utensils and chopping boards are one of the best surfaces for harbouring bacteria.
Re:Or there's the other option. (Score:5, Informative)
...except the truth is, wood cutting boards are less likely to harbor bacteria in a way that causes illness [nih.gov], because it tends to isolate and kill the bacteria. Plastic, on the other hand, is nonporous so the bacteria stays on the surface... and since it tends to develop grooves from the knife cutting into it, bacteria gets trapped in the grooves where it is hard to clean. Plastic cutting boards sanitized to NSF specifications may be safer, but most homes lack the technology to do that, or don't use it if they do.
Re: (Score:2)
Plastic must be bleached or heated to kill bacteria, dishwasher works. Once plastic has scratches simply wiping doesn't work anymore.
Re: (Score:2)
Toxicity is always a matter of quantity. Salt is toxic in large enough quantities. Are you going to eliminate salt? Even water is toxic, in large enough quantities.
When deciding what to avoid, zero tolerance is not valid or wise.
Math isn't a strong point in academia (Score:4, Interesting)
I'm going to put the blame on highschool and university math teachers. In most coarses blindly memorizing without understanding what you are doing leads to the highest marks. Teaching to actually understand the problem is seen as unfair because the exam might have a question that wasn't exactly covered in class.
Re: Math isn't a strong point in academia (Score:2)
This is sad to hear. Inability to do basic arithmetics is a form of illiteracy.
Re: (Score:2)
Re: Math isn't a strong point in academia (Score:2)
That's exactly the problem. If a nuclear or other apocalypse happens and calculators are no more, the survivors will be returned to the stone age.
Re: (Score:2)
If you have no number sense you cannot be sure the number is right. Maybe somebody accidentally tapped one too many zeroes.
Re: (Score:2)
Re: Math isn't a strong point in academia (Score:2)
For most day to day arithmetic, it's quicker to just do it in my head. I never remember where the calculator icon is on my phone.
Re: (Score:2)
I do, as often it's faster than pulling the phone out to fiddle with tiny touch sensitive interfaces. I often have to enter my PIN twice to get in because I can't even hit those numbers accurately.
Also, very important, knowing arithmetic lets you better know when the calculator is wrong! Very often using calculators or computers makes the operator assume that any output is correct, even if the input is wrong.
I have seen issues in many stores that have had power or networks go out, the staff is literally u
Re: (Score:2)
Re: (Score:2)
This is sad to hear. Inability to do basic arithmetics is a form of illiteracy.
I want to correct you to say "that would be ilnumeracy" but apparently "ilnumerate" is not a word.
It should be, though. Now I'm wondering what that says about my literacy.
Re: (Score:2)
A different letter doubles: innumeracy.
Re: (Score:2)
Thank you for that.
Innumerate was in my head and I rejected that based on the different prefix. English really is the gift that keeps on giving.
Re: (Score:2)
I think it's inherited from Latin. Spanish has the same thing where the in- prefix changes before some letters (im- before b or p, i- before l, ir- before r).
Re: Math isn't a strong point in academia (Score:2)
"numeric illiteracy" is the phrase you're looking for.
Re: (Score:2)
My snag is that I will occasionally use "m" for micro in some emails instead of "u" and then confuse people...
Re: (Score:2)
Teaching to understand the problem is impossible because the average IQ of the students is plummeting and schools have a political and social mandate to graduate students at the specified rate.
Re: Math isn't a strong point in academia (Score:2)
How can I drop? It's always measured against your cohort. If your whole cohort is getting stupider, the IQ values will still have a median of 100.
Re: (Score:2)
Re: Math isn't a strong point in academia (Score:2)
So you're definitely one of those people who doesn't understand what IQ means.
Re: (Score:2)
What happens if more people go to school and stay in school vs the past?
I don't know or even necessarily believe the premise is true (all I've been hearing my whole life is how they're forcing people to stay in school and forcing them ahead etc. etc., but I don't see a particular drop over the decades).
But it seems possible the average IQ in school or of highschool graduates can change over time. And for college is seems extremely likely that with an increase in people attending the IQ could change.
Re: Math isn't a strong point in academia (Score:2)
If you learned decimal places at university, it's most definitely not the university's fault.
Re: (Score:2)
Re: (Score:2)
"These people can memorize equations but don't understand them" made me think she may be a biologist or is surrounded by them
Correct and almost all her clients are biologists. A few chemical and material engineers but they can do math.
Re: (Score:2)
I mean no disrespect to them at all, I, a physicist, can barely memorize anything! Math though, that's like my second language.Sometimes feels like my first language!
Re: (Score:2)
Math should be treated as a required 2nd language. It should also replace 2nd language study in school... meaning MORE required math. They can also slow down the rate and really hammer points home so Americans can realize 1/4 is less than 1/3 (that is a problem.)
If people want to learn another human language, they can travel somewhere which also will teach them far far more than they ever could get in a classroom. Given how massive communication is and the problems it creates, we need to better focus on pr
Re: (Score:2)
Re: (Score:2)
Doesn't matter if you personally are offended. The generation screwing things up as the largest voting block for generations earns the blame. The greatest generation gets credit for great things; boomers don't even earn all the credit they get. Furthermore, the good work of youth doesn't erase the bad work of the much longer middle and late stages of life. I've known plenty of boomers; they didn't fight for civil rights at all, they weren't against it but they did nothing at the time. Vietnam too. But they
Re: (Score:2)
I recommend you look at the a great British documentary series : "The century of the self" to see how things shifted; it's also impacted subsequent generations.
https://www.imdb.com/title/tt0... [imdb.com]
Re: (Score:2)
-Two eyes are better and all that.
Re: (Score:2)
*and that was 10 years ago. I don't know what the going rate is now.
Re: (Score:2)
And yet, teaching the understanding of math freaks out a lot of people who think you just need to memorize. Big backlashes over "new math" and anything else that tries to get young brains to understand mathematics and not just memorizing times tables.
Phew! (Score:1)
Which form of confirmation bias? (Score:3)
This error sailed through review because the results most likely confirmed the authors' presumptions - that fire retardants are dangerous to human life when used in common utensils.
Apparently this survived rigorous internal review? Nope, it survived their hopes and dreams.
Re: (Score:2)
Re: (Score:2)
No need for confirmation bias here. The study had nothing to do with judging the safety or even comparison against the EPA numbers, that would be a different fantasy study everyone else made up in their head. This study was to see what quantities of these chemicals were released and if the quantities are unexpected. Nothing more. The reviewers would have made a detailed review of the math in the raw data (which was correct) and confirmed the conclusion of the thesis was backed up by the data (which it was).
Best to avoid these utensils (Score:2)
We already have plenty of exposure from countless other sources. Increasing it significantly is a bad idea, especially in food. Also epa limits are influenced by politics, usually lowered, so I don't feel confident about them. I prefer to stay as far below as possible.
Was this intentional? (Score:2)
Did the scientists want a particular conclusion and worked backwards from there using knowingly fake date, hoping not to get fact checked?
Re: Was this intentional? (Score:2)
Never attribute to malice that which can be explained by stupidity.
Even without the error... (Score:2)
The test itself was extremely unrealistic even without the math error. To show that the relevant chemicals could leach into cooking oil, they immersed the spatula in boiling cooking oil for a full 15 minutes. Nobody actually cooks like that. In real-world usage of just stirring for 2-3 seconds every minute or two, the dose would have almost certainly been well below the incorrect number.
Re: Even without the error... (Score:2)
There are many things I stir almost continuously; like noodles. Otherwise it boils over quickly (small apartments lead to small pots). I wouldn't do it with oil though, and I use a wooden spoon.
Re: (Score:3)
The peerage (Score:2)
Peer review fail.
Rule of thumb (Score:2)
Rule of thumb: if you see a "science" story pop up that sounds scary and recommends buying something, it's junk science.
I've been safely avoiding clicking on this alarmist black plastic headline for the last couple of weeks. Any headline that sounds scary is bullshit.
Re: (Score:1)
Rule of thumb: if you see a "science" story pop up that sounds scary and recommends buying something, it's junk science.
I've been safely avoiding clicking on this alarmist black plastic headline for the last couple of weeks. Any headline that sounds scary is bullshit.
Way to live without fear! Nothing can hurt you --by definition!
It's so true that there is absolutely no history of science discovering a public health issue, it's a shame people don't get that... so much wasted anxiety.
Re: Rule of thumb (Score:2)
I didn't have to click on promoted link to find out about COVID.
But if you prefer living in a state of fear, all the power to you.
Virgin plastics for food and drinks please (Score:2)
This is why I roll my eyes when a food or drink manufacturer proudly advertises their item is encapsulated in recycled plastic.
Like mineral water in bottles made from recycled plastic. Really? One of the world's best solvents is in contact with material you cannot trust. You do not know what exactly is leaching into the water. And that's a good thing?
Virgin plastics only in contact with food and drinks, please!