The average amount of a substance or condition (such as noise) you can be exposed to over an eight-hour day.
As set forth by State or Federal law, a maximum level or concentration of a hazardous substance, averaged over an eight-hour day, to which employees may be exposed. Employers are required to monitor their workers' exposure to certain substances to determine if exposures are in compliance with established TWAs.
the level of exposure that is allowed based upon a full work shift of 8 hours.
The averaging of different exposure levels during an exposure period. For noise, given an 85-dBA exposure limit and a 3-dB exchange rate, the TWA is calculated according to the following formula: TWA = 10.0 Log(D/100) + 85 where D = dose.
An allowable exposure concentration averaged over a normal 8-hour workday or 40-hour workweek.
The 8-hour average airborne concentration that shall not be exceeded in any 8-hour work shift of a 40-hour work week. Also see permissible exposure limit. The Attachments for Appendix D: file name: d_atts.pdf A word about pdf files. next (Appendix D, sections III - V)
A time-weighted average is the "average" exposure over the working day. The time-weighted average numerical limits that are listed assume that there is an 8-hour exposure. If worker exposure occurs over a longer period and/or there is not a 16-hour period between exposures, then adjustments may have to be made to these values from a legal standpoint and/or to conform to fundamental toxicological principles.
The average time, over a given work period (e.g., 8-hour workday), of a person's exposure to a chemical or an agent. The average is determined by sampling for the contaminant throughout the time period. Represented as TLV-TWA.