gavreid
Pretty Words...
That is the only risk with them though, a breach in the oven cavity large enough for the waves to pass through.
Classically yes but that's not quite true. Even though the grid on the door is considerably smaller than the wavelengh of the micowaves, you will get some leakage through it.This is called an evanescent field, which falls off in intensity very sharply (exponentially) with distance. That is why you should stand back and not press your nose to the door!