19 Things You Should Never Microwave BySamantha Bansil, 08/18/2021 Gourmandize shares Share on Facebook Share on Twitter Pin it Share on WhatsApp Share on Google+ 13/19 Previous Next © Thinkstock Aluminum Foil It's no secret that aluminum foil, which contains metal, is very bad for your microwave. It will also certainly catch on fire, making for a very dangerous situation. Watch out for foil take-out containers, too.