I have been nuking food since childhood, but no one ever taught me the Rules of Microwaving. I learned not to put any metal in one when I went to re-heat a foil-wrapped Wendy’s hamburger, and I learned the dangers of superheating liquids in chemistry class. No one warned me about chili peppers, however.
It’s perfectly fine to cook or soften sweet or bell peppers in the microwave, but nuking spicy chilis should be avoided, unless you like pain and suffering. Capsaicin—the molecule responsible for the pepper’s heat—is a fairly volatile thing, and microwaving a pepper will cause it to release its capsaicin, effectively filling your microwave with DIY pepper spray.
When you open your microwave, that homemade pepper spray will waft right into your face, eyes, and respiratory system, which is painful. Exactly how painful (and potentially damaging) depends on how spicy your chili pepper is, but things can get extreme. Back in 2016, WHAM TV reported that a hazmat team had to be called to an apartment building all because of a single microwaved pepper. No major injuries were reported, but tenants had to be evacuated due to irritation. (They did not, unfortunately, reveal what kind of pepper it was.)
Luckily, there is an easy way to avoid such troubles: Don’t microwave spicy peppers. Cook them on the grill, or in a pan, or roast them in the oven—and even then, consider turning on a fan if you’re working with a pepper that has a lot of capsaicin. (Unless you’re grilling them; most grilling takes place outside.) And, if you happen to have independent children who like cooking their own food, make sure they’re aware of the microwave no-gos. Metal may be the most obvious, but the dangers of DIY pepper gas should probably be somewhere on the list.