What Should and Shouldn't I Microwave?
More often than not, you're going to need to put your foods and drinks in something to microwave them. Here are the materials that work best as containers and the ones to avoid.
- Glass containers. These are probably the best to use, since there's zero debate about how safe they are in the microwave
- Most paper plates, towels, and napkins. However, because some paper towels are made with plastics and some paper plates and cups are coated with plastic, National Sanitation Foundation (NSF) International recommends only using those products marked as microwave-safe
- Ceramics, although Ceramics Today recommends only porcelain and stoneware, rather than ceramic dishes that may have been low fired, because those could possibly explode; their article offers a test to figure out if a piece would be safe to microwave (if you knock on it and it has a clean ring, it's probably fine). Plates with metallic paint can also cause sparks
- Wax and parchment paper, as well as microwave cooking bags are deemed fine too, according to NSF International
- Aluminum foil. Technically, you can use foil in the microwave (fun fact: Hot Pockets microwaveable containers and similar foods have aluminum lining), but it might not be the wisest thing to do
- Metal containers (e.g., canned foods in their cans), for the same reason above
- Brown paper bags from the grocery store. Per the USDA: "They are not sanitary, may cause a fire, and can emit toxic fumes. Intense heat may cause a bag to ignite, causing a fire in the oven... . The ink, glue, and recycled materials in paper bags can emit toxic fumes when they are exposed to heat. Instead, use purchased oven cooking bags"
- One-time storage containers like take-out containers, margarine tubs, or yogurt containers
- Plastic trash bags, garbage cans, or film canisters. I had no idea people consider these cooking vessels, but nevertheless the University of Nebraska warns against using these items for microwave cooking
- Plastics. This is the big one people fear cause cancer. Even BPA-free products leach hormone-like chemicals (although new research suggests it might not be as bad as previously thought). The jury's still out, though, on the health implications of microwaving or dishwashing plastics. The Environmental Working Group advises against microwaving foods or drinks in any kind of plastic container at all. The FDA, however, approves containers for microwave use based on their measures of the chemicals leaching out; as Harvard Health reports: "The maximum allowable amount is 100–1,000 times less per pound of body weight than the amount shown to harm laboratory animals over a lifetime of use. Only containers that pass this test can display a microwave-safe icon, the words "microwave safe," or words to the effect that they're approved for use in microwave ovens."
- Styrofoam. Similarly, some Styrofoam products are marked "microwave safe"
- If you do decide to microwave in plastic containers, just make sure they're not cracked, old, or discolored. And when covering food with plastic wrap, make sure the plastic doesn't touch the food.