Which gas is heavier than air and can accumulate in low areas?

Propane is heavier than air, which allows it to accumulate in low-lying areas if it were to leak. This characteristic is crucial for safety considerations, especially in confined spaces or areas with poor ventilation. When propane escapes, it tends to settle to the ground rather than disperse into the atmosphere, creating a risk of explosion or fire if ignition sources are present. Understanding the physical properties of propane helps technicians assess and mitigate hazards associated with leaks.

In contrast, natural gas is lighter than air, meaning it will rise and disperse rather than accumulate; butane, while also heavier than air, is less frequently encountered in scenarios similar to propane; hydrogen is significantly lighter than air and poses different safety considerations.