Reheating leftovers or cooking foods in the microwave are quick and easy ways to prepare meals and snacks. Is it safe to cover your food with plastic wrap when cooking in the microwave? Plastic wraps are made from plastic resins and some contain PVC or DEHA, which can be harmful if the wrap is used improperly. The more flexible a plastic wrap is, the greater the chance it will contain more PVC. When PVC compounds are heated, they can migrate into your food, especially if the food is high in fat. Small amounts of these compounds pose no harm. If you choose to use plastic wrap when cooking, be sure to keep it from touching your food by covering it loosely and leaving a corner turned back to vent. And avoid reusing plastic wraps. The next time you are shopping for plastic wrap, check the label or ask the manufacturer to see if the product contains PVC or DEHA. Another tip: When cooking your food in the microwave, use glass or microwave-approved plastic container.