ATEX (Atmosphères Explosibles) are two EU-Directives concerning explosion safety. The overall purpose of the EU-Directives is to protect workers potentially at risk from explosive atmospheres.
In this context explosive atmosphere means a mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours, mists or dusts in which, after ignition has occurred, combustion spreads to the entire unburned mixture.
ATEX ‘workplace‘ Directive 1999/92/EC sets the minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres.
Ex-sign used to indicate a hazardous area with potentially explosive atmospheres
ATEX ‘product’ Directive 2014/34/EU applies for equipment and protective systems intended for use in potentially explosive atmospheres.
Ex-symbol for equipment and protective systems intended for use in potentially explosive atmospheres
Hazardous places are classified in terms of zones on the basis of the frequency and duration of the occurrence of an explosive atmosphere.
Zone 0 – explosive gas atmosphere
A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist is present continuously or for long periods or frequently.
Zone 1 – explosive gas atmosphere
A place in which an explosive atmosphere consisting of a mixture with air or flammable substances in the form of gas, vapour or mist is likely to occur in normal operation occasionally.
Zone 2 – explosive gas atmosphere
A place in which an explosive atmosphere consisting of a mixture with air of flammable 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.
Zone 20 – explosive dust atmosphere
A place in which an explosive atmosphere in the form of a cloud of combustable dust in air is present continously, or for long periods or frequently.
Zone 21 – explosive dust atmosphere
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 – explosive dust atmosphere
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.
Employers and equipment manufacturers must follow the requirements in the EU- Directives to get access to the European Single Market. For employers this includes classification of areas in their facility into zones where potentially explosive atmospheres may occur. Furthermore, manufacturers supplying equipment to be used in those zones must ensure that the equipment does not contain any effective ignition sources. Finally, manufacturers of protective systems intended to reduce the consequences of an explosion must undergo an extensive test and certification program.
If you want to learn more, feel free to contact us about ATEX training.
