these gasses, or as. like to call them 'stink clouds' are often spawned when bathrooms overflow from a full waste line and nowhere for it to go. If you have vents setup, you can trap stink clouds by building bulkheads instead of doors, because they block airflow. But uh, yeah once a stink cloud gets into an open room it really spreads fast. Best thing is to build vents to allow oxygen flow, and trap it off with bulkheads. even putting a bulkhead to seal off where your bathrooms are is good practice I believe.
I tried all of these (bulkheads, vents), I have 26 waste ejectors and a waste processor with 3 hazmeeps working, but yet I somehow can't seem to get past these stink clouds. A bathroom ejected a stink cloud, but when I looked 1 second later the waste capacity of my space station was at 0/1650 liters. Is there something like a limit of how much waste can flow through a single waste line or something? Or do you have another way to solve this problem?