Getting bisphenol A out of food containers


I up in our Green Chemistry special edition of the podcast. We have contributing correspondent. Warren Cornwall here with the story about finding a replacement for the common can lining chemical this funeral a or commonly known as EPA these days high. Warren you start with this fulcrum this point where the tab of a can of soda attached to the body of the Cana Soda. Why is that a good place to start the story? I never knew how amazing the science and engineering around making I can was started reporting this story in this particular case. Ace this point where the pull tab is. Attached to the top of an aluminum drink can is subject to these huge stresses. You have to imagine that the inside of this whole can is covered in this. Thin layer of plastic can't break in order to attach this poll tab to the top of the can Dan basically after pound with a machine on the can top to create this little bump and then the pull tab sits on the bump and then you mash that bump flat because the what is saying. It's the most difficult fabrication in the whole universe. But I think he says in their whole universe okay that makes you and the whole universe the people at Sern would appreciate that but in the universe can fabrication for linings. That's their crux. We're GONNA talk about the lighting's the special liner inside of these cans usually contains. BPA OR A. What exactly is the purpose can't ends contained all kinds of material that can potentially be corrosive all kinds of acidic drinks? I don't know if you remember from elementary school. Well experiment where one of your teachers would put a nail inside of a jar with coq a few days later. It'll be gone so yeah stuff is corrosive And apparently the kinds of stuff that we're putting into cans now is even more corrosive than it used to be. All of these kinds of fancy craft beverages energy. He drinks so they don't want to eat holes in the cans and then the flip side of that. Is that if you've ever put a piece of aluminum in your mouth. It tastes weird and you don't I don't want that flavor to go into the food or drinks so the properties a can lining material have our resists corrosion. Obviously obviously what other things are important. Doesn't create any weird flavors of its own. Ideally it's inert so it doesn't react with anything It's inside the can in a perfect doc world. It's not at all toxic. It's still a benign. It has to be as cheap as possible and it has to go on the cans really easily really quickly quickly because they're cranking out cans at a rate of two thousand a minute so BPA. Which I think most people have heard of at this point because of concerns about its effect on health? Health checks these boxes except for the health one. What are the health concerns when it comes to? BPA well the main concern is that it can mimic estrogen when the body encounters BPA it can bind with estrogen receptors. Enough that the body. Can I think that it's binding with estrogen. There's a lot of debate going on about how much of a health risk is really posed by. EPA in the levels that it's founded pardon people's bodies the FDA still allows it to be used in most food related containers with the exception of baby bottles and sippy cups so the is said that the science suggests that it's not really a problem in other settings said the chemical industry and other industry groups have taken that got same message but you have consumer groups environmental groups and some university researchers that have done work suggesting that it can be problematic one of the stats. You mentioned in your story. About how more than ninety percent of people who live in the US have EPA in their urine. We pretty much that'd be a and US And some governments non. US governments have also decided to ban PBA right. You know the only one that I know of its flea abandoned his France right and you know one of the thing. I should know just going back to a comment that you made earlier about. BPA and cans. I've been told that for food cans in the United States about ninety percent of it is non. BPA At this point so food cans like peas and corn drink cans to or know for aluminum. EMINEM drink cans. It's about fifty fifty. Okay they've cut way down on this but about how much. BPA is still out there. Do you know how many cans with US liner are made. Every year they are every month. Yeah estimates are worldwide that we crank out about four hundred fifty billion with a B. Tans every year yeah three hundred hundred and fifty billion of those are aluminum drink cans the other one. Hundred billion are food cans some not small percentage are lied with. That's right you talked to. Scientists at a company called Thou spar that came up with a a new alternative a few years ago and a very unusual way. How did they get involved? Vow Spar in two thousand seventeen was purchased by Sherwin Williams. Okay this company had a business. Making chemical can linings and and one of the significant parts of that business for them was making BP based linings but they and other manufacturers were seeing the pushback from consumers and some governments guest EPA and so they were looking for alternatives. What they were finding is that? The alternatives had drawbacks right. Some of them were for more expensive or didn't hold up as well or did perform in some way that Kanye manufacturers wanted or for if they were trying to find a replacement in the same family of chemicals as BPA that family abyss females. There was concern sern that those chemicals were going to have some of the same health related concerns that beep at everybody was pushing to find a replacement because the biggest fear fear is that governments are going to step in and say no more. BPA Right. I mean the thing that's interesting to me is that they decided to go for it. Because you can imagine a company saying Oh man that could be a really expensive yet and there's a guy in the story who kind of figures in the Tom Tom Mallon and he's interesting because he's very much industry insider he's worked at. This company is whole life but he from the outset said look. We're going to have to go about this a different way. We're GONNA have to reach out to people outside the industry people outside. The industry don't necessarily trust US anymore when it comes to things like BPA safety so we're going to have to think about this a different way. People tell me that this is really unusual. This is a real culture shift. So what did they do to narrow the pool of chemicals out there to replace. VP aligning so they bring in a chemist from the outside who has experience in the pharmaceutical industry and the pesticide industry. So basically he had this long list of bisque dolls. That might work as can liners and the first green that he did was running them through a computer program that would see whether they were likely to fit in the estrogen receptor or not and then the ones that came out as potentially a non estrogens they then sent off for a series of slab screenings. The basic one was a yeast screening where these yeast cells have been engineered to glow when they're exposed to estrogen compound. At that point they have to do more tests to find out if these chemicals are also going to work well as a can liner they finally narrow it down to one candidate. Wow it's called Tetra. Methyl BIS Funeral F or T. Mbps they narrowed it down to this one mechanical and it had passed them basic tests when it came to its ability to affect estrogen receptors. And it was able to stand up to The harsh environment of inside a can. This is where they turn to. Basically they turned to their critics and said you tell us that this isn't safe to wasn't said they were challenging them the way they described it to me as they were coming to scientists and saying we want to build a better molecule for this. What should we do to make sure that it's actually going to be safer? Yeah they posed this question to environmental and public health advocacy groups and they impose that same question to researchers who have done a lot of science studying BPA and they actually took the chemical to their labs and tested faceted out and a bunch of different ways. That's right they set up the payment in a way that the scientists said they kept their independence so so the best example is a endocrinologist at Tufts. Anna Soto has done a lot of work on. EPA and its effect on in breast tissue the company made a contribution to tufts with no strings attached so it was not hurt to her lab specifically and then she came to tufts and said give me money for my research search and she found that there weren't Astra genetic effects from this alternative to be. Yes right she didn't find any evidence that was stragetic And then the secondary element that that was interesting is that she didn't find evidence that the can lining was leaching any of its T. M. B. PF contents into into the liquids. This letting him ICAL has been approved by the FDA for use in food product container. So it's already on the market. It's already something that people have probably encountered in their day to day life. The company has their chemical has been used to line twenty two billion cans since twenty seventeen nine. Wow so a lot of cans but a small fraction of the overall universal cans right going back to the safety testing that we talked about. I think it sounds is wise to approach people who have built up the skills to test for Indian disruption in their labs but is there ever a way to know if something is safe. It's kind of like the bigger question if the FDA's testing aren't necessarily rigorous enough. What should be happening to show that a chemical a safe to go sit next to food that might absorb it? That's an open question. Part of what was interesting to me about. This story. Is that when val spar went looking for an alternative Bernard route for testing their product. There was no road map for them to follow And that's still the case. They can't point to a battery battery of tests and say look. We have jumped through these hoops that everybody has agreed are the hoops that we should jump through did it successfully and therefore we can declare our chemical to be a gold star. Green label chemical. Is there a movement to codify. Something is an endocrine disruptor if it does this and if it doesn't do these things these five things or these ten things and it's not an endocrine disruptor. There are various efforts to come up with better more more rigorous more detailed ways of screening chemicals for possible construction. Regulators would argue that they currently have tools for declaring declaring whether a chemical is an endocrine disruptor or not and they're working on improving them so it's not like they're saying that their ways the the only way and there's no improvement to be done right our other companies going to follow this model of looking for chemicals to replace something that people have a lot of questions sweat and then turning to people outside industry to test it for health concerns. I don't know I mean I've talked to some people who've said that they think it it's a promising model. They think that the experience of Alice bars had suggested a company can do it successfully. But you know I've talked to other people who've said that there are companies who are working to develop greener safer chemicals but have really chosen to do it internally and keep it to themselves salves partly because there is a concern that if you say that you're trying to replace one of your chemicals with something safer you're bringing attention into concerns about safety of the clear curly us. Well thank you so much more and I sure thank you Sarah. Warren Cornwall is a contributing correspondent piece in Washington State. You can find a link to his article and the rest of the special section on chemicals. Tomorrow's Earth at science mag dot org slash podcast

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