Zone 0 1 : An area in which an explosive gas-air mixture is continuously present or present for long periods. Equal to a Division 1 hazardous location in the United States and Canadian classifications
EESiFlo North America, Terminology and Glossary: Explosion Proof & Hazardous Areas, Pennsylvania, USA 2002, flowmeterdirectory.com/flowmeter_terminology, (Mrtm/ Explo Proof and Haz Areas - Amer) {561}