What is the minimum amount of coal dust required for an explosion?

The minimum amount of coal dust required for an explosion is crucial for understanding mine safety and risk management. The correct choice indicates that approximately 0.08 ounces per cubic foot of air is necessary to create a condition where an explosion can occur. This threshold is significant because it reflects the concentration at which coal dust can ignite and produce an explosive force when mixed with air.

This specific value is derived from studies on dust dispersion and its combustible properties in underground environments, where factors such as particle size and moisture content contribute to the likelihood of ignition. Understanding this concentration helps mine foremen and workers implement effective dust control measures to prevent explosions—such as proper ventilation, regular dust monitoring, and the use of suppressants—thus enhancing safety in operations.

The other values presented do not align with the established minimum threshold for ignition, which is why they are not the correct answer.