Firefighter Practice Exam

Which term describes a liquid substance that has a low flashpoint?

1. Stable

2. Volatile

3. Compressible

4. Non-combustible

The correct answer is: Volatile

The term that describes a liquid substance with a low flashpoint is "volatile." A volatile liquid is one that can easily vaporize into the air at relatively low temperatures, making it more flammable and prone to ignition. The flashpoint of a substance is the lowest temperature at which it can form an ignitable mixture with air, and a low flashpoint indicates that the substance can ignite easily under normal temperature conditions. In contrast, other terms like stable refer to a material's resistance to chemical change or decomposition, which does not directly correlate with its flashpoint. Compressible refers to the ability of a substance to decrease in volume under pressure, and non-combustible indicates that a material does not combust, which is the opposite of what a volatile liquid represents. Thus, the characteristics of volatility are specifically tied to the low flashpoint of a substance, highlighting its potential hazards in firefighting and safety scenarios.