Is it dangerous to microwave plastic?


A recent Canstar Blue survey of more than 1,100 Australians found that 86% of us considered a microwave to be an essential household appliance. Nevertheless, 28% of respondents admitted to being worried about the health risks associated with microwave use.

An often-cited cause of concern is the risk of chemicals leaking from plastic that is heated in a microwave and contaminating the food. But is this risk real? Here’s the advice from several Australian organisations.

Cancer Council

Takeaway food containerYou should always use plastic containers that are made with the intention of using in the microwave, as the International Agency for Research on Cancer says there is not enough evidence to suggest there is evidence that products that are intended for use in microwaves cause cancer.

However, don’t use plastic takeaway containers or other plastic containers that aren’t intended for microwave use, and only use plastic wrap in the microwave if it is labelled as microwave safe.

Australia Radiation Protection and Nuclear Safety Agency

Similarly, the Agency warns that plastic containers not specifically designed for microwave use shouldn’t be used in the microwave. Ditto cling wrap. To quote: “The high cooking temperatures may cause the plastic’s chemistry to break down and thereby contaminate food in the container.”

The Agency advises that most ceramics, glass-ceramics and papers are fine.


The CSIRO reiterates the above advice – that only items designed for the purpose should be used in the microwave. Further, even if your container is “microwave safe” – it should be binned when it starts to show signs of wear and tear.

Interestingly, the CSIRO claims that the leaching of chemicals into food from non-microwave safe containers is more likely if you’re heating fatty foods. Something to keep in mind!

Swinburne University

Swinburne offer much of the same guidance as above and adds that plastic grocery bags, newspaper and plastic containers for frozen foods (such as ice-cream) should not be used in the microwave.

Some things to keep in mind…

Overall, you should only use containers in the microwave that are labelled “microwave safe”. If you’re still in any doubt, some tips include:

  • Woman saucepan stovetopWherever possible, even when buying takeaway in convenient plastic containers, transfer food to glass or ceramic bowls instead before heating. You could even go old-school and use a saucepan on the stove!
  • Even microwave-safe containers have a used-by date. When you containers start to look worn or have chips, scratches and cracks, it’s time to bin them and buy some new ones.
  • Something to keep in mind when defrosting – unwrap the frozen items from the (likely) plastic bags that they have been stored in before putting them in the microwave.
  • Cling wrap may melt during the heating process if it’s touching the food, so keep it well clear. Consider paper towels or a glass lid instead.
  • Check the plastic containers for a label that says “microwave safe”.

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