Glossary of Terms: V

%VOL
Concentration of gas, measured in percentage by volume.
%v/v
Another way of representing %VOL.
Vapor density
A measure of the density of gas or vapor relative to air. Gases or vapors with a vapor density less than 1 are lighter than air.
Vapor pressure
Pressure (measured in pounds per square inch absolute - psia) exerted by a vapor. If a vapor is kept in confinement over its liquid so that the vapor can accumulate above the liquid (the temperature being held constant), the vapor pressure approaches a fixed limit called the maximum (or saturated) vapor pressure, dependent only on the temperature and the liquid.
Vapor
The form that a gas or liquid takes when it evaporates into the air.
Vapors
Gaseous form of substances that are normally in the solid or liquid state (at room temperature and pressure). Vapor can be changed back to solid or liquid state either by increasing the pressure or decreasing the temperature alone. Vapors also diffuse.
Vibration
The back and forth motion of an object (for example, tool, machinery or other piece of equipment) that occurs in a predictable pattern or manner. Over-exposure to vibration can harm a part of the body (for example, the fingers) or it can affect the whole body.
Viscosity
The property of a fluid that resists internal flow by releasing counteracting forces.
Volatile organic chemicals (VOCs)
Benzene, formaldehyde and outgas from industrial processes; high hazard potential
Volatility
The tendency or ability of a liquid to quickly vaporize into the air. Such liquids as alcohol and gasoline, because of their well-known tendency to evaporate rapidly, are called volatile liquids. Liquids that are volatile must be carefully dispensed and stored, including paying special attention to temperature.