Zone 2 1 : An area in which an explosive gas-air mixture is not likely to occur and if it does occur, will only exist for a short time. Equal to a Division 2 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}