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Comment by OJFord | Hacker News Reader

> Ars has reached out to the lead author, Megan Liu, but has not received a response. Liu works for the environmental health advocacy group Toxic-Free Future, which led the study.

Clearly the authors had their conclusion even before doing the study, so of course the error doesn't affect it.

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On the most charitable level, the "huge math error" occurred in the calculation of the FDA's limits on exposure, so if the group feels that the FDA set its limits too high and the amount of chemicals being leached is worrying, then the math error really doesn't affect their conclusion at all.

But digging into the study, it becomes clear that the authors are really reaching in their methodology--subjecting utensils to rather implausible scenarios (when was the last time you microwaved your sushi tray?)--to try to get some samples that would exceed the limit. The hyperbolic media coverage of "ditch all your black plastics" isn't really sustained when the research finds that just a few specimens, when subjected to unusually high heat stresses, managed to just barely cross the incorrectly-calculated FDA threshold (itself likely set at a factor of a tenth to a hundredth of the lowest threshold observed to cause issues in previous studies!). That the authors aren't willing to disavow that media coverage is more telling then their unwillingness to adjust their conclusions in response to their math error.

> subjecting utensils to rather implausible scenarios (when was the last time you microwaved your sushi tray?)

That's not implausible. Sushi actually tastes better a little warm than chilled.

Also I think it would make sense to test all food trays the same way, as some of those do get heated quite a bit (e.g. I've microwaved take-out noodles in plastic trays very similar to a take-out sushi trays). It's not like it's plausible that there's some special sushi-tray supply chain where they've carefully determined they can safely get away with using e-waste plastic. It's almost certain that industry consists of many takeout tray companies that each make a whole line of takeout trays for different uses using the same raw materials (e.g. the sushi cart at my employer sold sushi and hot noodle soup in black plastic trays, which plausibly could come form the same manufacturer).

I microwave my sushi for precisely this reason — for ten or twenty seconds at most — not half an hour.

In general with all the microplastics floating around, I found it not a large investment to divest of 95% of the plastic in my kitchen (there was a lot), including the black variety, and only cook in stainless/carbon steel, ceramic enameled cookware, and glass with wood or stainless steel utensils and only drink filtered water. It's not hard to get most of the plastic out of your kitchen at least, but there are tons of other sources; clothes, furniture, devices, etc. I'm working on minimizing some of that as well. One of the most frustrating things is you can't find a drip coffee maker with an all metal full path for the water to grounds path. Everything I looked at had a ton of plastic unless it was $700+, so I live with the ritual of the french press for now

Pour-over funnels have glass and ceramic options, and the coffee turns out quite tasty.

80% of maximum fire retardants entering food or 8% of maximum fire retardants entering food are both "too much fire retardants entering food".

Seems like the conclusion very obviously still holds, so I'd agree with the study authors here, that error doesn't alter the conclusion.

> 80% of maximum fire retardants entering food or 8% of maximum fire retardants entering food are both "too much fire retardants entering food".

OK, but that's not what this study was about, right? The original claim by the authors was that these utensils brushed up against safe limits. When that turned out to be false, the claim has shifted to the safe limits are too high. But that's a different study. You need to do a safety analysis of exposures to the substance. That's not what their study did.

It doesn’t affect the conclusion so who cares what the study was about initially?

Their conclusion that these utensils are dangerous depended on the results that showed these utensils are at or about the FDA's maximum safe dose. But after correcting the math error, it turns out they're actually about 1/10 of that. That invalidates their conclusion.

1/10th is still high? And doses aren't a on/off amount. It's not like there's no risk until you hit 100% and then there's max risk. Exposure is exposure.

There's a lethal dose for alcohol, but having 1/10th of that dose can still strongly negatively impact me.

> 1/10th is still high

Based on what? The FDA's safe dose by definition means there are no known significant risks. They build in pretty hefty safety margins in these things. It definitely could still be too high! We get things wrong all the time. But you need a different kind of study to show that.

Based on: the EPA regulates doses not the FDA, there are no human studies for these chemicals at all (the amounts are based on rats and mice), the dose isn't a "safe dose" it's a "reference dose", and a standard human is exposed to a few hundred nanograms of these chemicals normally in a day while cooking with these introduces tens of thousands of nanograms per day.

So, baseline, one day of using black cookware exposes you to a years worth of baseline exposure. Every day. That's why I consider it high. These are known bioaccumulating carcinogenic compounds. I can reduce my baseline by over 99% by spending $10 on a new spatula? Yeah, that's high.

No. The authors state that their conclusion is not altered by the change in calculations. As per TFA:

> "This calculation error does not affect the overall conclusion of the paper," the correction reads. The corrected study still ends by saying that the flame retardants "significantly contaminate" the plastic products, which have "high exposure potential."

How is that clear? Perhaps they are a group that exists to do studies like that.

Groups that exist to do studies like that can be biased toward gainful employment and suppress anything that threatens the revenue stream.

Can but in this case it’s still unnecessarily toxic with 8% of the EPA limit

And they can also do real studies with plenty of scientific legitimacy. Without evaluating the studies you have no way of knowing if they're biased or not and you're just spreading conspiracy theories.

That is pretty much my point, yes.

So instead of 80% toxic limit it’s „only“ 8%.

Sorry but I don’t want any toxic material in the tools I use for food.

It's not 'toxic material', it has a toxic dose. Too much water and you die. You do want some percentage of that level of water, though.

The brominated flame retardants are inherently toxic and are therefore considered toxic materials.

The point is that nothing is inherently toxic, as there are almost certainly trace amounts of countless different compounds that are "inherently toxic" all around you. Again, it depends on the dose. I don't think there are many, if any, chemicals where a dozen molecules would negatively affect a healthy adult.

I would wager that you inhale more than zero molecules of this "inherently toxic" flame retardant when you breathe. So you are going to stop breathing?

Especially since it can build up in the body. Kind of like some vitamins you can have 1000% of the RDA because they are very water-soluble and go through like a sieve anyway, but others get toxic much quicker because they are fat soluble and get stored in fat cells for the long haul.

How many spatulae are you planning on eating?

It's important to consider that the average person is probably much less likely to eat a spatula that is on fire.

Therefore, simply averaging the flame retardant content of a random sample of spatulas could result in a bias.

It's precisely the ones that are the most toxic that one would expect to be the most edible.

First, you have to find a spatula with the specific compound in question.

Less than 10% of items studied contained the specific compound in the article.

FTA:

    The study examined 203 black plastic household products, including 109 kitchen utensils, 36 toys, 30 hair accessories, and 28 food serviceware products. Of those 203 products, only 20 (10 percent) had any bromine-containing compounds at levels that might indicate contamination from bromine-based flame retardants, like BDE-209. Of the 109 kitchen utensils tested, only nine (8 percent) contained concerning bromine levels.

    "[A] minority of black plastic products are contaminated at levels >50 ppm [bromine]," the study states.

    But that's just bromine compounds. Overall, only 14 of the 203 products contained BDE-209 specifically.

Only 10% across the board, but what’s the probability that one or more of black plastic food tools in a given home contains bromine-based fire retardants?

Probability is a bitch.

It’s adds up with all the other sources of toxic material we are exposed to.

Fun fact: oxygen is toxic in high enough concentrations.

Wtf bro. So is 0 oxygen intake. But 0 toxic intake isnt, so it's fair to say you want 0.

Are you familiar with the phrase "the dose makes the poison"?

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