Opening 3 : A gap or void 30 inches (76 cm) or more high and 18 inches (48 cm) or more wide, in a wall or partition, through which employees can fall to a lower level
US Department of Labor, OSHA Construction eTool: Glossary (General Construction: electrical Incidents, Falls, Struck-By, Trenching And Excavation) Occupational Safety & Health Administration OSHA, Washington, D.C., USA 2010. https://www.osha.gov/SLTC/etools/construction/glos sary.html, (OSHA/Gen Const - Amer) {615}
