What Type of Plastic Is Safe in Microwave Ovens?

Safe Plastics

• Out of the seven common types of plastic found in food containers and packaging, three are generally considered safe for microwaving and storing food: high density polyethylene (HPDE), polyethylene terephthalate (PET) and polypropylene (PP), according to legal and engineering professional Stan Protigal. Polypropylene is the most commonly labeled "microwave safe" plastic widely used. Although these plastics are safe for microwave use, always check for the "microwave safe" marking before use.

Sometimes-Safe Plastics

• Containers made from low-density polyethylene (LDPE) may be safe or not. Some containers made form this material are labeled "microwave safe," while others are not. Always check for this label. Paper containers are food-safe but not those that are coated in plastic.

Dangerous Plastics

• Polyvinyl chloride (PVC), polystyrene, styrene (PS) and polycarbonate are not safe for microwave use. PVC and polystyrene, for example, usually contain the chemical bisphenol A (BPA), which gets released by heating in microwave ovens. BPA is a known human carcinogen.

General Safety Rules

• When cooking with plastics in the microwave, follow certain safety rules. According to the FDA, you should not use plastic grocery bags, newspapers or aluminum foil in the microwave. Don't allow plastic wrap to touch food, as it can melt and contaminate food. Don't use plastic storage containers intended for one-time use, such as take-out containers, margarine tubs or whipped topping bowls. Also, vent the container before microwaving food by leaving the lid ajar.