What Does Time Weighted Average Exposure Value (TWAEV) Mean?
A time weighted average exposure value (TWAEV) is the value assigned to a hazard exposure calculated from averaging the level of several samples taken over a specified period of time.
A TWAEV may be used to define safe exposure levels for various workplace hazards. Often, a TWAEV will be imposed for exposures to hazardous substances such as chemicals or other airborne contaminants. When workplace safety regulators set permissible exposure limits (PELs), the limit may be based on the average exposure that occurs during an 8-hour work day or a 40-hour work week.
Time weighted average exposure values may also be referred to as time weighted average (TWA). The term may also be hyphenated (time-weighted average exposure value).