Need some movie help from one of you movie buffs

Hey guys, I need help finding a title of a specific film. It was released in the early 80's I think. The plot revolved around these 4 or 5 people having to be quarantined by the military. I can't remember if it was because of a toxin or if the military was experimenting on them. Anyway they had to be quarantined and could not breathe normally and had to wear masks. If they took off the masks they died. One scene has this guy taking off his mask and breathing and then his brain literally expands and blows out the top of his head. In the end, the military killed them all (I think). Anyway if one of you guys knows this film please tell me the title lol