Vapor Density

Vapor density refers to the comparative weight of a vapor relative to air, which is assigned a standard value of 1. Vapors with a density exceeding 1 are denser than air and will accumulate in lower elevations, posing risks in confined spaces. Conversely, vapors with a density below 1 are lighter than air and will ascend, dispersing into the atmosphere. Not to be confused with vapor pressure, which indicates the tendency of a substance to evaporate, vapor density is critical for situational awareness in Hot/Warm/Cold Zone management during hazardous material incidents.