Critical Time : The time required for unignited fuel to accumulate in such quantity and proportions that, if ignited, the pressure of the resultant explosion would constitute a hazard (See: AS1735 for methods of determination)
Ministry of Business, Innovation and Employment, Glossary of terms and acronyms, Wellington, New Zealand 2010. http://wwwsosh.govt.nz/resources/glossary-u.shtml, (Occupn Hlth and Sfty - Brit) {530}