What does a combustible gas indicator (CGI) measure?

• A. The temperature of hazardous materials
• B. The concentration of flammable gases and vapors
• C. The pressure of gas tanks
• D. The pH levels of liquids

Answer: (B)

A combustible gas indicator (CGI) is a device specifically designed to detect the presence of flammable gases and vapors in the environment. By measuring the concentration of these gases, the CGI helps responders assess the potential explosion risks associated with various hazardous materials. This is critical in safety management during incidents involving combustible substances, as knowing the concentration allows for appropriate action to mitigate risks, such as evacuation or ventilation.

In contrast, measuring temperature, pressure, or pH levels pertains to different areas of hazardous materials management. Temperature is vital for understanding the thermal stability of materials, pressure gauges monitor the state of gas within tanks but not their flammability, and pH measurement is essential for assessing the acidity or alkalinity of liquids, which is unrelated to gas combustibility. Each of these functions is significant in its context, but the CGI's role remains focused on identifying flammable gas concentrations, making it a crucial tool in hazard assessment and response scenarios.