A protective device which requires a machine operator to activate two start controls simultaneously before the machine will operate, the object being to keep the operator's hands out of the danger zone
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}