NICET Fire Alarm Practice Exam

Group C gases are classified based on their Maximum Experimental Safe Gap (MESG) values, which are crucial for determining ignition risks in various environments. The MESG value indicates the maximum safe gap through which a spark or flame can travel without igniting the gas-air mixture.

For Group C, the MESG values specifically fall within the range of 0.45 mm to 0.75 mm. This classification is based on a standardized criterion that helps in assessing the flammability and explosivity of gas mixtures. Gases in this category present a moderate level of ignition risk due to their gap characteristics, hence requiring careful consideration in fire safety planning and design.

The specific range of 0.45 mm to 0.75 mm effectively captures the properties of these gases, and understanding this classification is essential for professionals working with potentially hazardous materials. Proper identification and handling of Group C gases is critical to maintaining safety in environments where they are present.