Is it possible to prevent or stop the teargas?

In the bank heist (and perhaps other heists), the cops can send teargas through the vents.

I think it's possible to prevent it by killing the cops on the roof, but is it possible to stop it afterward ? The gas tank is pretty easy to spot, but can't be destroyed or interacted with.

The only way to prevent the gas is by killing the cops on the roof, which get dropped via a chopper. Bane warns you when a chopper is inbound, so get up there and liquidate them.

If there is already tear-gas, you cannot "switch it of". I searched for quite a bit, but cannot find something that states that you can get rid of tear-gas.