Ontario Firefighter I Certification Practice Exam 2025 – Complete Study Resource

Vapor density specifically pertains to the density of gases in relation to air. It is a measurement that compares the mass of a certain volume of a gas to the mass of an equal volume of air at the same temperature and pressure. This is crucial in contexts such as firefighting and hazardous materials response because it helps determine whether a gas will rise or sink in the air.

Understanding vapor density is essential for evaluating the behavior of various gases when released into the environment. For instance, gases with a vapor density less than that of air tend to rise, while those with a vapor density greater than air will accumulate near the ground. This knowledge aids firefighters and first responders in making informed decisions regarding ventilation, confinement of hazards, and safety measures during an incident.