Indoors, cylinders stored must be located at least how far from combustible materials?

• A. 5 ft.
• B. 20 ft.
• C. 50 ft.
• D. 0 ft.

Answer: (B)

The key idea is providing a safe buffer between stored cylinders and any combustible materials to minimize the risk if a cylinder leaks or vents and to reduce the chance that heat or flames could reach nearby combustibles. Indoors, maintaining twenty feet of separation gives enough space for gas to dissipate, for ventilation to help carry away any leaked gas, and for emergency access and response without nearby materials catching fire.

Five feet is typically not enough to prevent ignition if there’s a leak or radiant heat from a nearby fire or equipment. Zero feet places combustibles right next to the cylinders, which is unsafe. Fifty feet is more than necessary in most settings and reduces usable space without added safety benefit. Therefore, twenty feet is the appropriate minimum distance.