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Home Frequently Asked Questions Hazardous Zones 1, 2, 21 & 22

Hazardous Zones 1, 2, 21 & 22

Gases, Vapours and Mists

Zone 1 – Zone 1 hazardous areas are considered to be a place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally.

Zone 2 – Zone 2 hazardous areas are classified as a place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapour or mist is not likely to occur in normal operation but, if it does occur, will persist for a short period only.

Dusts

Zone 21 – A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is likely to occur in normal operation occasionally.

Zone 22 – Zone 22 hazardous areas are a place in which an explosive atmosphere in the form of a cloud of combustible dust in air is not likely to occur in normal operation but, if it does occur, will persist for a short period only.