Nor can you prove something safe by performing a limited number of tests. If you want to prove something safe, you have to test it under all possible conditions. The fact that exhaustive testing is not feasible does not eliminate the logical requirement for such testing. It merely forces us, sooner or later, to be pragmatic and say that we’ve tested six ways from sunday and found can’t find any hidden dangers. That does not constitute proof that such dangers are not there under conditions which were not tested.
engineer_comp_geek’s claim that an unmeasurable quantity, the “absence of people dying”, somehow proves the safety of microwaveable plastics is absurd. People die. No one knows what kills most of them. Usually it’s called old age, but that’s really a catchall term for a bunch of different things that we’re not really sure about. There’s no way to tell for sure exactly what did not contribute to someone’s death.
The claim that microwaved plastics “actually drips poisonous toxins into the food” is extreme because there’s very little evidence to back it up. Similarly, the claim that “plastics are safe to use in the microwave” also suffers from a lack of empirical evidence. Of course there is some evidence for the safety claim, but it is actually impossible that there will ever be enough to constitute a formal empirical proof of safety.
For an example of a similar situation, take the humble potato. People have been eating it for hundreds of years. It’s generally regarded as safe. However, if you get a little too smug about your potatoes, and carelessly toss that fancy one with the overly green skin in with the others for a fancy salad, you may suddenly find yourself sick as as a dog with solanine poisoning.
Given our relative inexperience and lack of knowledge about the combination of food, plastics, and microwaves, a little caution is warranted.
Sorry, I was thinking diethylstilbestrol (DES) and wrote thalidomide. (both teratogens from the 50’s,60’s). I’m not particularly attacking the FDA here, only pointing out that they do make mistakes, or miss things that later turn out to be important. Everyone does when faced with the unknown. While avoiding plastics in the microwave altogether is probably over-extreme, so is the thoughtless use of just any bit of plastic you have lying around as a container to heat up your supper.