Emails in recent years have warned of the alleged dangers of microwaving food in plastic containers or covered with cling wrap. Many different chemicals are involved in the manufacturing of many different types of plastic. Although some of these may cause cancer, there is no convincing scientific evidence to suggest that any products that are intended for use in microwaves cause cancer.
Manufacturers that make plastic containers for food storage use different substances and make containers differently than when they make containers for other uses. Plastic containers that are not intended to be used in microwaves could melt and may leach chemicals into food.
Not all types of cling wrap are suitable for use with all foods. For example high fat foods, such as cheese, pies, or fatty meats should not touch cling wrap when being heated in a microwave. Additionally, it is not safe to use cling wrap if it could actually melt into the food, like in an oven or on pots and pans. Instructions on the packaging of cling wrap should describe with which foods and under which conditions the product should be used.
In Australia, the Australia New Zealand Food Standards Code, administered by theNSW Food Authority sets out the requirements for the surfaces in contact with foods, including plastic containers and cling wrap. The Australia New Zealand Food Standards Code are legislative instruments under the Legislative Instruments Act 2003. Products must be fit for their intended use and made from a material that will not leach into, contaminate or taint the food. For cling wrap specifically, ensure that you purchase cling wrap manufactured from UV stabilised food grade polyethylene/polyvinyl chloride (PVC), which complies with the Australian Standard.
It is recommended that people avoid microwaving plastic containers (e.g. take away containers, margarine tubs) or cling wrap that are not intended for the microwave. Only use plastic containers or cling wrap in the microwave that are labelled as microwave safe.