Requests sometimes arrive asking for “an ATEX paint booth”, as though it were a model to order or a certificate to attach. The text itself knows nothing by that name. It is two European directives, each addressed to a different party, and reading them together is what turns the word into a specification that can be checked item by item.
ATEX zones in paint booths start from one definition shared by both directives: an explosive atmosphere is a mixture with air, under atmospheric conditions, of flammable substances in the form of gases, vapours, mists or dusts in which, after ignition, combustion spreads to the entire unburned mixture. Solvent vapour, paint mist and a powder cloud all fall within those forms whenever the material is flammable.
Two directives, two addressees
Directive 2014/34/EU addresses the product. It applies to equipment and protective systems intended for use in potentially explosive atmospheres, and to safety, controlling and regulating devices used outside those atmospheres but required for the safe functioning of that equipment. Directive 1999/92/EC addresses the employer. It sets minimum requirements for protecting workers potentially at risk from explosive atmospheres. The first says what the equipment must be; the second says where it is used and how the place is managed.
A zone is defined by frequency and duration, not by equipment
Directive 1999/92/EC requires the employer to classify places where explosive atmospheres may occur into zones in accordance with its Annex I. The definitions turn on two questions: how often such an atmosphere forms, and how long it lasts when it does. The text defines normal operation as installations being used within their design parameters. So a classification does not ship with the chamber from the factory; it is decided by assessing the place and the way work is done in it.
| Gases, vapours and mists | Dust in air | Explosive atmosphere as described in the text |
|---|---|---|
| Zone 0 | Zone 20 | Present continuously, for long periods or frequently |
| Zone 1 | Zone 21 | Likely to occur in normal operation occasionally |
| Zone 2 | Zone 22 | Not likely in normal operation, and if it occurs it persists for a short period only |
The same annex adds that layers, deposits and heaps of combustible dust must be considered as any other source which can form an explosive atmosphere. Accumulated dust enters the assessment just as a suspended cloud does.
The category follows the zone
Directive 2014/34/EU divides equipment-group II, the equipment intended for places other than mines, into three categories: category 1 at a very high level of protection, category 2 at a high level, and category 3 at a normal level. Unless the explosion protection document states otherwise, Annex II of Directive 1999/92/EC links each zone to the categories allowed in it, provided the equipment suits gases, vapours or mists or dusts as appropriate:
- In zone 0 or zone 20: category 1 equipment
- In zone 1 or zone 21: category 1 or 2 equipment
- In zone 2 or zone 22: category 1, 2 or 3 equipment
That annex refers to the older, repealed directive; under the repeal article of Directive 2014/34/EU, such references are construed as references to the current directive.
What to read on the equipment plate
Annex II of Directive 2014/34/EU requires every item of equipment and protective system to be marked legibly and indelibly with the manufacturer’s name and address, the CE marking, the series or type designation, the batch or serial number if any, the year of construction, and the specific marking of explosion protection followed by the equipment-group and category symbol, then the letter G for atmospheres caused by gases, vapours or mists, or the letter D for dust.
That is why an ATEX requirement in a tender is complete only when it is written with three elements: the zone, the category, and G or D. Offers are then checked against the marking and documents of each component.
A document that comes before operation
Directive 1999/92/EC requires the employer to draw up an “explosion protection document” before work starts. It demonstrates that explosion risks have been determined and assessed and which places have been classified into zones, and it is revised when the workplace, work equipment or organisation of the work undergoes significant changes, extensions or conversions. The assessment itself takes account of the likelihood that ignition sources, including electrostatic discharges, will be present and become active.
When ATEX becomes binding
Both directives state in their final article that they are addressed to the Member States, so their legal force applies within the European Union. Outside it, ATEX becomes binding on a particular project when a tender or the requirements of the competent authority call for it, and it is then read through zones, categories and marking as above. In the Kingdom, applicable requirements differ by city, facility location and activity, and they are reviewed at the site survey before the specification.
This is an explainer of the directives’ text as published in the Official Journal of the European Union and read on 2026-09-11. It does not replace a site assessment or the explosion protection document that belongs to it.
Frequently asked
Is an “ATEX paint booth” a defined product?
The text defines no product by that name. Directive 2014/34/EU applies to equipment, protective systems and their components, and Directive 1999/92/EC classifies the place. The right question for each component working inside a classified zone is its category and whether it suits gas or dust.
Who decides the zone inside and around the booth?
Under Directive 1999/92/EC the employer classifies places into zones and records them in the explosion protection document. Classification rests on how often an explosive atmosphere forms and how long it lasts in the actual way of working, not on the name of the equipment.
Is powder coating classified differently from liquid paint?
The text separates two kinds of zone: zones 0, 1 and 2 for gases, vapours and mists, and zones 20, 21 and 22 for dust. It treats layers and deposits of combustible dust as a source that can form an explosive atmosphere, so accumulation enters the assessment alongside the suspended cloud.
What should a tender state instead of the word ATEX alone?
The classification of each area as set by the site assessment, the category required for equipment in it, and the atmosphere type as G or D, together with a request for each component’s marking and documents. Written that way, an offer can be checked item by item rather than accepted on the word.
Related reading
Practical next step
Send your facility location and finishing material, and the zone classification if one has been prepared, and we start from the requirements applicable to your project before the specification. Contact an expert. The published range sits on the paint booths family page.