What Is ATEX?
ATEX safety refers to European Union directives that establish safety requirements for explosive atmospheres. ATEX is an abbreviation of the French term “ATmosphères EXplosibles”. Its core purpose is to ensure the safety of equipment and protective systems in workplaces where explosive atmospheres may occur.
Two Main Directives Fall Within the Scope of ATEX
ATEX 114 (2014/34/EU)
Applies to manufacturers. It covers the design, manufacture and system configuration of equipment and protective systems intended for use in potentially explosive atmospheres.
ATEX 153 (1999/92/EC)
Applies to employers and operators. It covers explosive-atmosphere management, risk assessment, worker safety and the measures that must be taken.
Classification of Hazardous Areas
For Gases
Zone 0: Areas where an explosive atmosphere formed by a mixture of air and flammable substances in the form of gas, vapour or mist is present continuously, for long periods or frequently.
Zone 1: Areas where such an explosive atmosphere is likely to occur occasionally in normal operation.
Zone 2: Areas where such an explosive atmosphere is not likely to occur in normal operation, or where it occurs only for a short time if it does occur.
For Dusts
Zone 20: Areas where combustible dust in the form of a cloud is present continuously, for long periods or frequently.
Zone 21: Areas where combustible dust in the form of a cloud is likely to occur occasionally in normal operation.
Zone 22: Areas where combustible dust in the form of a cloud is not likely to occur in normal operation, or where it occurs only for a short time if it does occur.
Note
Places where combustible dust is present in layers, deposits or heaps must also be considered as a potential source of explosive atmospheres.
Use of Suitable Equipment (ATEX-Certified Products)
All equipment, including fans, motors, sensors, lighting and control panels, must be ATEX-approved.
Any component with the potential to generate sparks must be controlled.
Equipment must be designed to prevent self-heating and static-electricity accumulation.
Criteria for Selecting Equipment and Protective Systems
Unless otherwise specified in the explosion-protection document prepared through risk assessment, equipment and protective systems in all areas where explosive atmospheres may occur are selected according to the relevant ATEX equipment categories.
For gases, vapours, mists and dusts, the following equipment categories are used in the specified zones.
Zone 0 or Zone 20
Category 1 equipment
Zone 1 or Zone 21
Category 1 or 2 equipment
Zone 2 or Zone 22
Category 1, 2 or 3 equipment
Explosion Risk Analysis and Documentation
Explosion risk must be assessed in every ATEX environment.
An Explosion Protection Document must be prepared and updated regularly.
Employers must document that employees have received training and have adequate awareness.
Sources
1) Guide to Directive 2014/34/EU
2) Directive 1999/92/EC of the European Parliament and of the Council
