It should be noted that in the particular case of hydrogen, gas escaping under pressure can reignite so that consideration may have to be given to allowing the flame to burn or managing it with a narrow cone of water.
Any cylinder found to be physically damaged or heated by fire should be treated with caution after the fire has been extinguished as it may have been weakened, increasing the risk of cylinder failure.
Gas leak
If there is a gas leak from a valve, a simple operation to isolate could be carried out by closing the valve. If the leak cannot be stopped, as a cylinder only holds a finite amount of gas, after a period of time the gas will have escaped and will no longer present a hazard.
Personnel should understand the properties of the gases involved, which includes that:
- Hazardous materials may be flammable, oxidant, asphyxiant, toxic or corrosive
- Some will be heavier than air, some lighter than air, which will affect their behaviour if released
- If released as a liquid, the liquid will fall to the ground and will usually quickly convert to a gas. The gas, if lighter than air, will then rise into the atmosphere.
- There is a large change in the volume between a liquid and a gas. There will be a much greater quantity of gas formed.
For further information refer to Hazardous materials: Release or spill of hazardous material