The average concentration of airborne contaminant measured over a normal 8 hour workday and 40 hour work week to which nearly all workers may be repeatedly exposed, day after day, without adverse effect
John Gilbertson (Ed.), Health and Safety Sound Bites, Category: Agriculture and Industry, Health and Safety Sound, County, ENCYCLO Online Encyclopedia, from Safety & Health Practitioner SHP (The Official Magazine of The Institution of Occupational Safety and Health (IOSH), United Business Media Limited, London, UK 2007. http://www.encyclo.co.uk/local/20474&page=4, (OSH - Brit) {117}