1854

Yes, but it tends to be self extinguishing.

that red canister is used for extinguishing fires

A self-contained fire extinguisher includes an extinguishing agent and usually a pressurized gas. In a CO2 extinguisher, the pressurized gas is also the agent.

No, it is not. Because hydrogen is flammable, it will burn in contact of the fire, instead of extinguishing it. So, generally the gas used for extinguishing fire is Carbon dioxide, which is neither flammable nor supports combustion