The majority of plastics can withstand microwave radiation and won’t break down nor melt. If you are buying commercial products, you might be able to find “microwave safe” symbols on them, which I think look like three squigly lines. Essentially, if you’re buying plastics that look like they were designed for storing food, then they are microwave safe.
Generally, for a plastic to be safe in a microwave it can’t react with the food, leach out components in the food, or decompose. A lot of storage containers such as plastic butter containers, sour cream containers, etc., can either melt or decompose. This also includes water bottles- don’t reheat water bottles if you want to be safe. Also, plastic bags from the grocery store should not be placed in the microwave.
Sometimes plasticizers in the plastic may leach into your food when microwaving. Specifically, fatty foods can make diethylhexyl adipate plasticizer (what makes the plastic soft) leach out. However, the FDA is on top of things when it measures and approves the amounts of chemicals that leach into the food, and these are quite small amounts. The FDA doesn’t have “microwave safe” labels on all of the plastics, but that doesn’t mean they aren’t safe for use. They just haven’t been sufficiently tested to know for sure.
The testing generally takes some assumptions into account, like what surface areas of plastic:food are going to interact, and the temperature that the plastic will reach, which is around 100o C for the boiling of water, which most foods are composed of. Some things get much hotter, though, like dry foods with oil (popcorn bags).
BPA: BPA is used as a precursor to the plastic called polycarbonate (PC). PC is used for those Nalgene
style bottles you see in heavy use. In other drinking bottles with different plastics, the levels of BPA are negligible. BPA is being studied for ill effects on the human body, however I’m not sure what the current consensus is in the biology field. It is potentially bad for the environment and some test animals, but I believe the testing on humans isn’t fully conclusive. But it is probably harmful to some extent. I’d rather a biologist talk more about that one, though, don’t take my word for it.
As far as the contamination is concerned, they believe that the temperature of liquid the bottles have been exposed to has a large effect on the release rate of this chemical. They took PC bottles and placed them in boiling water, after which the bottles released BPA anywhere from 15 to 55 times faster than if the bottle were only used with colder liquids. Source . If the bottles were used with only cool liquids, there was still a very small leak of the BPA into the water. It doesn’t seem like the amount of BPA will cause damage, however those tests are still being conducted.
BPA can be found in polycarbonate plastics, and anything labeled {3} or {7} for the recycling code. BPA simulates the action of estrogen and “A growing number of scientists are concluding, from animal tests, that exposure to BPA raises your risks of heart disease, obesity, diabetes and childhood behavioral problems such as hyperactivity. “
Given all of that, I wouldn’t put a Nalgene bottle in the microwave because the hot, boiling water may help leach what tiny amount of chemical there is in there, however something tells me it’s not that dangerous.
Theodore Lee is the editor of Caveman Circus. He strives for self-improvement in all areas of his life, except his candy consumption, where he remains a champion gummy worm enthusiast. When not writing about mindfulness or living in integrity, you can find him hiding giant bags of sour patch kids under the bed.