3 ms·This is why you should not open a microwave without stopping it, unless you want a dose of radiationby aussieguy1234 7y agoThis is why you should not open a microwave without stopping it, unless you want a dose of radiationeherot 7y agoRadiation which is, in small doses, mostly harmless, since it is of the non-ionizing variety.rmtech 7y agoIt's harmless.