How does one use a microwave in an office where people also use the microwave for their treif food?
I guess you dont (shouldn't).
you can.. there are ways. I don't know details though.
I think there are 2 routes to go about it
a)kosher the microwave
b)deal with the food container
koshering the microwave involves using a cup of water and moving it around and putting it on for x minutes.
dealing with the food container, I think is just having 2 layers..
some people use plastic, but that's probably dangerous - in terms of health. You shouldn't put plastic in the mirowave (except maybe, maybe, special plastic). And especially not around your food and in the microwave.
2 glass containers is another option.
something like that anyway.
Many would avoid the microwave 'cos they don't know or aren't confident in doing it.