Explosion protection zones - everything you need to know

Classification of Zones

According to Directive 2014/34/EU, a potentially explosive area is a space in which the atmosphere could become explosive on account of the local and/or operational conditions. These potentially explosive atmospheres are divided into zones. Depending on the frequency and duration of the occurrence of hazardous, explosive atmospheres. An explosive atmosphere is defined as a mixture with air, under atmospheric conditions, of flam-mable substances in the form of gases, vapors, mists or dust in which, after ignition has occur-red, combustion spreads to the entire unburned mixture.

Hazard gas/vapor/mist

Zone 0
A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapor or mist is present continuously or for long periods or frequently.

Zone 1
A place in which an explosive atmosphere consisting of a mixture with air of dangerous substances in the form of gas, vapor or mist is likely to occur in normal operation occasionally.

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

Zone classification for gas/ vapor/ mist

Hazard powder/dust

Dust clouds in the explosive region (above the minimum explosible concentration) are categorized into 3 zones, based upon the grade of release.

Zone 20
A place in which an explosive atmosphere in the form of a cloud of combustible dust in air is present continuously or for long periods or frequently.

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
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.