Which gas is heavier than air?

The correct answer is LP gas, which stands for liquefied petroleum gas. LP gas consists primarily of propane and butane, both of which are heavier than air. When released into the atmosphere, LP gas will settle in low-lying areas due to its density, which can create hazardous situations if proper precautions are not taken.

Understanding the behavior of gases is crucial for safety in fire investigation and management because heavier-than-air gases can accumulate in confined spaces and pose significant risks of fire or explosion if ignited. This characteristic influences how firefighters and investigators assess the scene and develop strategies for responding to gas leaks or fires.

Natural gas, on the other hand, is lighter than air, primarily consisting of methane. Hydrogen is also quite light, being the lightest element. Oxygen, while essential for combustion, is still lighter than many hydrocarbon gases, making LP gas the specific gas that is correctly identified as heavier than air.