Safety and SIS · Glossary
What is a Hazardous Area Zone?
Zone 0, 1, 2 and 20, 21, 22Safety and SIS
A hazardous area zone describes how likely an explosive atmosphere is at a location: Zone 0, 1 or 2 for gas and Zone 20, 21 or 22 for dust.
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Hazardous Area Zone Explained
Zones come from area classification to IEC 60079-10-1 (gas) and IEC 60079-10-2 (dust). Equipment must be certified for the zone it is installed in.
North America also uses Class and Division under NEC 500, or zones under NEC 505.
Hazardous Area Zone: Typical Values
| Zone 0 | explosive gas present continuously or for long periods |
| Zone 1 | likely in normal operation occasionally |
| Zone 2 | not likely, and only for a short period |
| Zone 20, 21, 22 | same idea for combustible dust |
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Calculators for Hazardous Area Zone
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Frequently Asked Questions
What is a Hazardous Area Zone?
A hazardous area zone describes how likely an explosive atmosphere is at a location: Zone 0, 1 or 2 for gas and Zone 20, 21 or 22 for dust.
Is Zone 2 the same as Division 2?
They are similar but not identical; equipment approvals are different.
Who decides the zones?
Area classification by competent engineers, based on release sources, ventilation and gas properties.
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