What Does Evaporation Rate Mean?
Evaporation rate is known as the rate at which a material vaporizes (or evaporates), meaning it will change from liquid to vapor when compared to the rate of vaporization of a specific known material.
This quantity represents a ratio, which means it is unitless.
Safeopedia Explains Evaporation Rate
Evaporation rate is an important factor in the evaluation of health and fire hazard qualities of chemicals and other substances, wherein a fast evaporation rate generally indicates a high health, fire, and/or explosion risk. A substance with a high evaporation rate quickly forms a vapor, which can be explosive or inhaled by occupational workers.
Substances with an evaporation rate of 3.0 (three times the evaporation of normal butyl acetate), such as acetone (5.6), hexane (8.3), or methyl ethyl ketone or MEK (3.8), are known as "fast evaporating." Substances with an evaporation rate between 0.8 and 3.0, such as ethyl alcohol (1.4) or VM&P naphtha (1.4), are known as "medium evaporating." Those with an evaporation rate of less than 0.8, such as water (0.3), mineral spirit (0.1), or xylene (0.6), are considered to be "slow evaporating."