One other note - often the coating is put on the can to protect the metal from the liquid inside and not the other way around. There are stories of poorly coated cans packed together where one becomes damaged, leaks onto nearby cans, damages them and so on. Quite a mess.
Tin cans are lined with epoxy. So "BPA" is actually BPA-derived epoxy resin, and so most likely formed from bisphenol A diglycidyl ether, not BPA per se. Since BPA diglycidyl ether is made by reacting BPA with epichlorohydrin.
And if you have no other (good) options, compromise by avoiding abuse (mechanical, heat, UV, harsh chemicals, acidic foods, dishwasher) and retiring the plastic early, 2-3 years.
Also, while all plastics leech, HDPE/LDPE & PP appear to be the best choices if you're concerned about this. BPA, BPS, etc are added to polycarbonate.
(In classic fashion, HDPE/LDPE & PP are the most boring of plastics)
The article you linked is specifically about BPS. The article that you are commenting about is about TMBPF and how the move to TMBPF is not just rebranding but an rather transparent search for a plastic that works and is safe.
I like the idea of avoiding plastic as possible, but saying "any move away from BPA is merely rebranding" is wrong and not helpful. This sort of alarmist comment is more likely to move people away from your point of view or at least give them incorrect ideas.
> TMBPF had another apparent advantage. Manufacturers use two chemical steps to forge BPA into can linings. In the second stage, some BPA molecules don’t get incorporated into the polymer chains. Those strays are thought to account for most of the BPA that leaches from linings. Valspar chemists found a way to use TMBPF just once, early in the process, stanching the release of the unlinked molecules.
The article is, at least somewhat, about their tetramethyl bisphenol F compound having a process advantage to bisphenol A which could reduce the leeching.
I wonder if there are any alternatives for sports drink bottles. Glass and metal bottles sound safest but you can't compress them to easily drink single handed.
Silicones exhibit many useful characteristics, including:[1]
>Low thermal conductivity
>Low chemical reactivity
>Low toxicity
>Thermal stability (constancy of properties over a wide temperature range of −100 to 250 °C).
>The ability to repel water and form watertight seals.
Does not stick to many substrates, but adheres very well to others, e.g. glass.
>Does not support microbiological growth.
>Resistance to oxygen, ozone, and ultraviolet (UV) light. This property has led to widespread use of silicones in the construction industry (e.g. coatings, fire protection, glazing seals) and the automotive industry (external gaskets, external trim).
Is also be concerned about residual chemicals from the manufacturing process, and this goes for metal too. For example I'm sure the molds have release spray that can get passed into the bottle, same with stainless steel machine spray, oils, and greases. And the thing with metal containers is that it's slightly porous and the chemicals can permeate a bit which would then leach back into the water. Another concern is low grade recycled metals with previous chemical contact used to manufacture the bottles of produced in places like China.
silicone doesn't require mold release on a nicely machined mold. If it IS required, such as with complex shapes, food-grade oils are used.
I suppose you could get a newly machined mold that may have cutting oil or something impregnated in the metal, but i'm not sure how you'd avoid that anywhere ,really.
(Just wash everything thoroughly when you receive it and buy from reputable dealers, that seems about as good as you can get.)
And yes, I agree it's something that's a concern with everything and I hate that I can't ignore it and it's always at the back of my mind. I used to work in FDA related manufacturing and I know how things operate.
As a consumer, how can I even tell if a can is using a coating and/or this coating? I had no idea the INSIDE wasn't aluminum with the 'usual' hydrogen ion layer.
"... sell its coating in the United States, branded as valPure V70. It has been used in 22 billion cans since 2017. That’s a modest fraction of the estimated 350 billion aluminum beverage cans and 100 billion steel food cans produced each year worldwide."
I'd prefer to use these cans over the BPA alternative.
Almost all aluminum cans for food products are coated. You can safely assume there's a coating of some kind. Some brands print "BPA free" on their cans. At this point that's the only information available to consumers.
I cannot find my source, but even BPA free means they just coat it with BPS which is structurally and functionally similar. I suspect the toxicity studies just have not been done yet.
I have a friend who used to work in the coatings lab for PPG circa 2007. He had a handful of chemicals to choose from that he would blend and test until the outcome fit the manufacturing requirements. It was not tested for toxicity before it was sent on to manufacturers and into your soda/veggie can.
This article is about TMBPF, a BPF, not a BPS. It is also structurally similar to BPA and the article is all about the struggle to effectively determine whether it is safe (and how this struggle has been very open which according to the article is not common for chemical companies). Many toxicity studies have been done and seem promising.
> Many toxicity studies have been done and seem promising.
The article implies a bit more of a mixed bag than that. Some were promising and some were troubling. I'm not a chemist but I think the most generous stance to give would be "cautiously optimistic" and I still think that's overselling it based on what I just read.
"Outside researchers didn’t deliver uniformly good news, however. Valspar approached scientists at Baylor Medical School, who found that TMBPF blunted estrogen’s effect on test cells and that a polymer made from the molecule had a similar effect on testosterone, according to a 2017 paper in PLOS ONE. Adam Szafran, a molecular biologist who helped lead the research, says the findings weren’t conclusive and could be specific to the prostate cells they tested.
"Mallen acknowledges that those results raise questions about the compound. But he says company-sponsored research showed that changes in test cells don’t translate into effects on an entire organism. That study, published online in Food and Chemical Toxicology in October 2019, showed no endocrine-related effects on rats fed TMBPF for 3 months."
The chance that this is a fairly safe chemical (or at the very least, a safer substitute for BPA) seems pretty promising so far. Of course, more studies should be and are planned to be done.
It's really hard to ignore the conflict of interest here. All of the company's research suggest it works, and the only other research mentioned in the article raises flags.
> All of the company's research suggest it works, and the only other research mentioned in the article raises flags.
That's not true. Soto, Maier, Maffini and Zoeller, all outside researchers, had findings in favor of TMBPF. I suppose it's fine to be skeptical though.
I too read that as a Call for Further Testing, and given the other tests, at least moving forward with using a likely safer coating based on the other tests.
It isn't unfathomable for a single study, pro or negative, to uncover a previously unconsidered test variable or other complication and it is entirely indicative that a followup study which has a larger sample size and better controls needs to be conducted to obtain more solid evidence.
Yes, I suppose I was partly correcting your statement "even BPA free means they just coat it with BPS" as the article was about a BPA alternative that is not BPS.
This is false. Can coatings packed with consumables undergo regulatory approval - even if the FDA doesn’t require it (though it often does) the coating customer will demand it, especially on a huge change like moving away from a component like BPA. There will be flavor testing, penetration studies, etc.
The base chemicals that my friend had to mix/boil/alter may get regulatory approval, but once he is done with the lab work the test batch was shipped and in short order the full amount. I specifically asked him if there was any testing between his lab and the manufacturing.
Edit: I see it could be implied in my original comment that there was never any testing whatsoever. I apologize.
It's simple. You contact the company that manufactures the product and ask they use BPA. If they reply 'no' then fine. If they don't reply then, yes, they use BPA.
I don’t understand the fear of BPA. It’s issues is that it’s a xenoestrogen and mimics estrogen in the body. Soy has the exact same property. We removed BPA from infant bottles but still allow soy based formula.
There has been a severe population-level decline in testosterone levels since the environment was flooded with xenoestrogens. This is a major global problem.
Soy is optional and consumed voluntarily, but BPA and other such chemicals have a significantly more potent long term effect, and contaminates everything it touches.
Yes, BPA accumulates in body fat. However, the environment has also been flooded with pornography which could also be responsible for the decline in testosterone/sperm counts, no?
No. This is not a trivial matter. The decline starts around the mid 20th century, is occurring globally, and levels have reduced by standard deviations from the old norm. Read up on it. It's way more serious than you think.
You're right, it isn't a trivial matter. However, neither has it been well explained. For example, how exactly has porn been ruled out? Porn also grew steadily since mid 20th C...
Correlation is not causation. Computing performance has also increased significantly since the mid 20th. Should we blame Intel for the drop in T levels? Where the hell do you get the idea that porn reduces testosterone? Research shows that watching porn increases testosterone levels in men https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2799222/
https://youtu.be/X1pB6O6AYMU
One other note - often the coating is put on the can to protect the metal from the liquid inside and not the other way around. There are stories of poorly coated cans packed together where one becomes damaged, leaks onto nearby cans, damages them and so on. Quite a mess.