Thoracic Dust : Dust of less than 10 microns in diameter which will escape the filtering effects of the nose and mouth and reach into the lungs. See: Total Inhalable Dust and Respirable Dust
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}