When storing compressed and liquefied gases, what precaution helps prevent ignition sources?

• A. Cylinders shall be purged, once empty.
• B. All cylinders, both full and empty, should be stored together to confine the hazard to a smaller area.
• C. Stored cylinders are secured so they cannot be knocked over.
• D. Empty cylinders should be removed from the premises immediately.

Answer: (C)

Preventing ignition sources when storing compressed and liquefied gases hinges on keeping cylinders from moving. If a cylinder is knocked over, the valve can be damaged or a leak can occur, releasing flammable gas that could encounter a spark or heat source. Securing cylinders upright with chains, straps, or in a fixed rack or cabinet prevents tipping and reduces the chance of leaks or ruptured valves, thereby lowering the risk of ignition.

Purging a cylinder after it’s empty, or removing empties immediately, don’t directly address the hazard of an ignition source in storage. Storing full and empty cylinders together or not securing them does not provide the same level of protection as simply keeping them from being toppled.