Norman Hermanson asked:
I have read your article regarding heating up food in a microwave in plastic and I understand what you said. I recently read an article where a student watered plants with water that was heated in a microwave and within 9 days the plant died. Any truth in this statement?
If I do not heat food in plastic containers is microwaving safe?
Dave - There are two aspects to this. One of them – is food in a microwave dangerous to eat? The other is, if you go near a microwave, is it dangerous?
First of all, microwaves are a form of light, a form of electromagnetic radiation. In the spectrum, you go from visible green, yellow, red, into the infrareds, the deep infrareds, through some millimetre waves and then there are microwaves and just beyond that, radio waves. And the further down in that direction you go, the less energy each photon of the light has got. So, the light which is actually dangerous itself is up in the ultraviolet which can give you cancer.
So, microwaves are probably not dangerous – they're certainly not dangerous with regards damaging cells chemically and giving you cancer. You can obviously get too hot from them and overheat because, the piece of chicken in a microwave obviously is getting damaged because that's way it gets more tasty. So, if you had a microwave with a hole in the back and you stood near it, then it would certainly be dangerous. But as long as the microwave is properly designed and you're not standing right up next to it and kind of leaning over it and hugging it, there shouldn’t be a problem.
Chris - And it won't do anything to the chemical composition of the food that you're heating up?
Dave - It’s heating the food up in broadly the same way as any other means of cooking, just making it hotter. The one difference is that it might not heat it quite as evenly. So you might get parts of the food which have essentially been overheated and if you overheat food then you can reduce the amount of vitamins in it slightly. So it’s not going to make it dangerous, but it might make it slightly less good for you.