Primary Explosive 1 : A sensitive explosive such as lead azide, which detonates by simple ignition from such means as spark, flame, impact, friction, or other primary heat sources of appropriate magnitude
United States Mine Rescue Association USMRA (membership,mine rescue and safety training resources, and mine disasters and accidents), Mine Safety and Health Quizzes, Glossary of Blasting Terms, PA,USA 2016. http: //miningquiz.com/pdf/Glossaries/Glossary_of_Blasti ng_Terms.pdf, (Blasting - Amer) {997}