What is the safest storage scenario for propane cylinders in or near a building?

• A. Store in a well-ventilated outdoor or semi-outdoor area, upright and secured, away from ignition sources; inside buildings is generally restricted unless designed for it.
• B. Store indoors near ignition sources for convenience.
• C. Store indoors with NO ventilation.
• D. Store horizontally on a shelf in a closed garage.

Answer: (A)

The safest way to store propane cylinders is in a well-ventilated outdoor or semi-outdoor area, kept upright and secured, and kept away from any ignition sources. Propane vapors are heavier than air and can linger near the ground or accumulate in enclosed spaces if there’s a leak. In an open or semi-open area, any leaked gas disperses quickly, greatly reducing the risk of fire or explosion. Keeping cylinders upright ensures the valve and safety devices function properly and prevents liquid propane from entering the regulator or leaking out through the valve. Securing them prevents tipping, which could damage the cylinder or valve and cause a leak.

Storing indoors or in a closed, poorly ventilated space creates a dangerous buildup of vapor that can ignite if there’s a spark or flame. Placing a cylinder horizontally on a shelf in a closed garage also increases risk because it can interfere with the valve and release propane more readily, and the enclosed space doesn’t allow vapor to dissipate safely.