BPA in food containers


When does it become dangerous? Do we inhale it or do we ingest it? what happens to food containers with bpa that get microwaved?

In: Chemistry

There isn’t good evidence that it is dangerous at levels coming from plastics containing food/drink. It affects the endocrine system, but it’s fairly weak in that action. The EPA and the European Food Safety Authority both say it shouldn’t be a problem at normal exposure, but some groups still express concern and studies trying to get more data are ongoing. BPA containing plastics leach it out more when it is warmed, so microwaving will increase leakage.

Knowing the nature of business and the power of Money, in this Subject, the best course is NOT to use anything that has it in it-like bottled water. I always carry an Army Canteen, with my OWN filtered water- and never a bottled water, not even for the dog;; check that espy not for the dog.

Picture a steel chain in your mind. Flexible, strong, super useful. A single link, however, doesn’t really do all that much.

Plastics are literally chemical chains. Individual molecules aren’t all that remarkable, but when connected in regular patterns they have incredible properties. Specifically, when BPA is mixed with phosgene, it forms polycarbonate- strong, clear, flexible plastic.

Now, if you ate pure polycarbonate, you’d be fine. Your body doesn’t really recognize it and it would eventually be excreted with other waste.

But to make polycarbonate, you essentially take a bowl and mix BPA with phosgene. Unfortunately, no chemical process is 100% efficient. There’s always a little leftover that doesn’t end up reacting. So intermixed with the polycarbonate product are little bits of unreacted BPA, sticking to the plastic.

If that plastic is then used to make a water bottle, some of that BPA may then dissolve into the water. When food is heated in a microwave, the container gets warmed up too. This helps dislodge the BPA from the plastic and allows more of it to dissolve into your food/drink. I also think BPA is used in things like thermal paper receipts, and touching them can cause BPA to dissolve into you through your skin.

The problem is that while polycarbonate isn’t that interesting to your body, BPA is.

Have you taken ibuprofen before? When your body feels pain, a enzyme binds to a molecule, let’s call it molecule X, and converts it into a chemical signal for the pain response. Ibuprofen looks enough like X that the enzyme tries to turn it into a signal too, but fails. So while the enzyme is wasting its time with ibuprofen, molecule X just sits around and nothing happens- no pain signal is created.

BPA works the same way. Enzymes in your body called hormone receptors bind to hormones (a type of chemical signal) such as testosterone and estrogen. Obviously these enzymes are really important for development. Testosterone tells your body to do one thing, estrogen another.

If you drink water with BPA in it, your body may absorb the BPA. BPA happens to look a lot like estrogen, so it binds to those hormone receptors and your body thinks it’s getting an estrogen signal, so starts to do things related to that signal.

Is it dangerous? It’s hard to say. We can give people more and more BPA until we notice bad things happen, but that isn’t really useful. Nobody is eating pounds of BPA, so if eating a pound of BPA is toxic, it isn’t that helpful to know that.

The problem is, what happens when you absorb tiny amounts of BPA over the course of years? If a few cells accidentally think they’re getting an estrogen signal once, it probably doesn’t do anything. But if they keep getting that response over and over and over again, does it add up? Does it matter for everyone, or just young people who haven’t fully developed yet?

The ideal experiment would be to have two identical babies, feed them exactly the same food and expose them to exactly the same stuff – all BPA free, but feed only one of them a little bit of BPA as well, and see if there are any differences.

Obviously, we don’t have 80 years to wait around and see those results, and it would be deeply unethical to experiment on babies like that, even if the experiment were possible.

So instead we have to make models that try to approximate things. The most common one is zebrafish, whose nervous systems are similar to ours. We can grow a lot of them, control their environments, and dissect their brains to study them.

There are more problems, though. How much BPA do we give them to be representative of how much BPA humans get? How does the BPA affect them and would it be the same in humans? Does it matter if the BPA comes from food or drink? etc etc etc

So ultimately, the answer is that we don’t know. The plastic lobby is really powerful and they make it very hard for scientists to get funding to study this. I personally know a few people who study BPA with these models, and their lives have been turned upside down by plastic companies smearing them and attacking them.

Should you be worried? Experiments in some models have shown pretty scary results if zebrafish embryos are exposed to BPA, but there haven’t been enough experiments to know if that’s really the fault of the BPA or if it’s a design flaw in the experiment. Honestly, at this point it could truly be either, and trying to apply those results to humans would be pretty worthless.

If you are a young child, have a hormone disorder, or are pregnant, it’d be something to avoid to be on the safe side. Otherwise…. do what you can if it makes you feel better. I can’t say if it’ll hurt you or do nothing.

I personally avoid touching receipts because there is no reason to even get them most of the time, and I try to use BPA free plastic. However, if someone hands me a water bottle and I’m thirsty, I don’t worry about it. In the grand scheme of things, it’s more dangerous to be in the sun (skin cancer), or eat junk food (heart disease) than it is to get a little BPA exposure.