Which gas is the principal gas found in coal and is associated with explosive hazards when present in air?

Which gas is the principal gas found in coal and is associated with explosive hazards when present in air?

• A. Oxygen
• B. Hydrogen
• C. Methane
• D. Nitrogen

Answer: (C)

Methane is the principal gas found in coal that poses explosion hazards when it mixes with air. In coal seams, methane is released during mining and can accumulate in enclosed spaces. When its concentration in air is within roughly 5 to 15 percent, it forms a highly explosive mixture and can ignite if there’s an ignition source. Because methane is colorless and odorless, workers rely on gas detectors and adequate ventilation to keep it from building up. Oxygen is the component that supports combustion, but it’s not the gas released by coal; hydrogen is also flammable but is not the primary gas associated with coal; nitrogen is inert and does not contribute to explosive hazards.

Methane is the principal gas found in coal that poses explosion hazards when it mixes with air. In coal seams, methane is released during mining and can accumulate in enclosed spaces. When its concentration in air is within roughly 5 to 15 percent, it forms a highly explosive mixture and can ignite if there’s an ignition source. Because methane is colorless and odorless, workers rely on gas detectors and adequate ventilation to keep it from building up. Oxygen is the component that supports combustion, but it’s not the gas released by coal; hydrogen is also flammable but is not the primary gas associated with coal; nitrogen is inert and does not contribute to explosive hazards.