Which of the following is not a GRASSFIGS hazard category?

• A. Earthquake
• B. Ground Strata Failure
• C. Air Quality
• D. Spontaneous Combustion

Answer: (A)

GRASSFIGS is a set of hazard categories used in underground coal mine risk assessment that focuses on hazards arising from the mine environment and operations, such as ground movement, gas and air quality, and self-heating ignition risks. An earthquake is a natural external geologic event and not a typical on-site hazard category within GRASSFIGS. Ground Strata Failure fits because it deals with instability and movement of the rock/roof and strata, which is a core mine-related risk. Air Quality fits because ventilation and exposure to dust and gases are key occupational hazards in mining. Spontaneous Combustion fits because coal can self-heat and ignite, posing a fire risk in the mine. Therefore, Earthquake is not considered a GRASSFIGS hazard category.