Sharing microwave with non-muslims to warm-up food

I work with non-muslims and all the employess in our company are non-muslims. During lunch break, I warm up my food (lunch) in the same microwave oven that everybody uses. I'm sure some of them eat pork and it is quite possible that some of the vapours of the food containing pork may be left behind after they use the microwave. I usually keep the microwave door open for sometime so that all the vapours are removed from the microwave. Please let me know if I it is alright to use the microwave oven for warming up my food. Jazakallah