In brief
ATEX refers to the EU explosion protection rules governing equipment for potentially explosive atmospheres and the protection of workers there.
Contents
What is ATEX?
The term ATEX derives from the French “Atmosphères Explosibles” and covers two EU directives. Directive 2014/34/EU is addressed to manufacturers and covers equipment and protective systems intended for use in potentially explosive atmospheres. Directive 1999/92/EC is addressed to employers and concerns the safety and health protection of workers potentially at risk from explosive atmospheres.
Employers classify hazardous areas into zones: zones 0, 1 and 2 for gases, vapours and mists, and zones 20, 21 and 22 for combustible dusts, graded according to the frequency and duration of occurrence. Equipment is divided into equipment group I for mining and equipment group II for other areas, with group II subdivided into categories 1, 2 and 3. The category determines in which zone a piece of equipment may be used. The marking includes, among other things, the Ex symbol, equipment group and category, the atmosphere (G or D) and, depending on the equipment, type of protection, explosion group and temperature class.
Replacement equipment and safety-relevant parts must meet the approval required for the zone at least to an equivalent level.
In practice: maintenance and procurement
When replacing equipment for hazardous areas, the complete Ex marking of the existing equipment should be available and checked against the plant's explosion protection document. Responsibility for the assignment lies with the operator; this entry is for guidance only and does not replace legal advice or inspection by a competent person.
Synonyms and abbreviations: explosion protection · Ex protection · ATEX Directive · ATEX 2014/34/EU · hazardous area equipment
Frequently asked questions
What is the difference between ATEX 2014/34/EU and 1999/92/EC?
Directive 2014/34/EU, often called the product directive, requires manufacturers to design, assess and mark equipment for potentially explosive atmospheres safely. Directive 1999/92/EC, the workplace directive, requires employers to assess risks, define zones and use suitable equipment. In Germany, the employer side is implemented mainly in the Hazardous Substances Ordinance and the Industrial Safety Regulation (GefStoffV, BetrSichV).
Which equipment may be used in zone 1?
In zone 1 for gases, vapours and mists, equipment of equipment group II with category 2G or 1G is permitted. Category 3 equipment is not sufficient there; it is intended only for zone 2. The explosion group and temperature class, which must match the substances present, are also decisive. The zone classification in the operator's explosion protection document is binding.
How do you read an ATEX marking?
The Ex symbol in a hexagon is followed by the equipment group and category, for example II 2G for equipment group II, category 2, gas atmosphere. For electrical and non-electrical equipment, this is usually followed by the type of protection, explosion group such as IIB and temperature class such as T4. This information shows the conditions under which the equipment may be used.
May ATEX equipment be replaced with equipment without Ex approval?
No. In a designated Ex zone, the replacement equipment must have at least the category required there as well as a suitable explosion group and temperature class. The requirements for maintaining explosion protection must also be observed during repairs. In case of doubt, competent persons or the responsible supervisory authority provide binding information.