| TWA |
| Time-Weighted Average. The time-weighted average is the average exposure concentration weighted for a normal 8- hour workday or 40-hour workweek, to which nearly all workers may be repeatedly exposed, day after day, without adverse effect. |
 |
| TWA |
| Time-Weighted Average. The time-weighted average is the average exposure concentration weighted for a normal 8- hour workday or 40-hour workweek, to which nearly all workers may be repeatedly exposed, day after day, without adverse effect. |
|