ATEX: selling equipment into European explosive atmospheres
If your equipment goes into a hazardous location in Europe, the rules are not a stricter version of the ones you already follow. They are a different system, and the difference starts with who decides what.
In the United States, you build to a Class and Division and the installation follows. In Europe, your customer classifies their own site into zones before they buy, and that classification determines the equipment category you are legally required to supply. You do not get to choose it, and you cannot work it out from the drawings alone.
That is the practical shape of ATEX, and it is the part that catches U.S. manufacturers.
Two directives, and only one of them is yours
-
Directive 2014/34/EU
Who it binds You, the manufacturer What it governs Equipment and protective systems intended for use in potentially explosive atmospheres -
Directive 1999/92/EC
Who it binds Your customer, as the employer What it governs Workplace safety, and the classification of hazardous places into zones
Fact — check it yourself
They meet at one point, and it is the point that matters: your customer’s zone classification determines the equipment category you must supply.
If they get it wrong, or never did it, you are designing against an assumption.
Directive 1999/92/EC, Annex II, Part B
The first thing to ask for is not a specification. It is the zone. In our experience the request lands as a surprise, and the answer often takes weeks to arrive — which is a schedule risk you should know about at quotation, not at delivery.
Groups and categories, in the order you need them
ATEX splits equipment into two groups:
- Group I — for mines susceptible to firedamp. Categories M1 and M2.
- Group II — everything else. Categories 1, 2 and 3.
The category is a required protection level, not a quality grade:
-
Category 1
Where it is used Places where an explosive atmosphere is present continuously, for long periods, or frequently Protection level Very high — must stay safe even with rare equipment faults -
Category 2
Where it is used Places where an explosive atmosphere is likely to occur occasionally Protection level High -
Category 3
Where it is used Places where an explosive atmosphere is unlikely, or present only briefly Protection level Normal
And this is the bridge your customer’s zone classification builds:
| Gas, vapour, mist | Dust | Equipment you may use |
|---|---|---|
| Zone 0 | Zone 20 | Category 1 only |
| Zone 1 | Zone 21 | Category 1 or 2 |
| Zone 2 | Zone 22 | Category 1, 2 or 3 |
A higher category always works in a less demanding zone. The reverse never does.
Fact — check it yourself
One caveat that is easy to miss, and works in your favour: this table is the default.
The directive applies it unless the customer’s explosion protection document, based on their risk assessment, states otherwise. So the zone is the starting point of the conversation, not necessarily the end of it — and where a customer’s classification is over-conservative, their own risk assessment is the instrument that can change it.
Directive 1999/92/EC, Annex II, Part B
When a Notified Body is unavoidable
Unlike machinery, where most products never see a Notified Body, ATEX makes third-party involvement mandatory for the higher categories. There is no harmonised-standards escape route.
-
Categories M1 and 1
Route EU-type examination, plus either production quality assurance or product verification Notified Body? Yes, always -
Categories M2 and 2 — internal combustion engines and electrical equipment
Route EU-type examination, plus either internal production control with supervised product testing, or product quality assurance Notified Body? Yes -
Categories M2 and 2 — other equipment
Route Internal production control, and the technical documentation must be sent to a Notified Body, which acknowledges receipt and retains it Notified Body? Deposit only — no assessment -
Category 3
Route Internal production control Notified Body? No -
Any group, as an alternative
Route Unit verification Notified Body? Yes -
Protective systems
Route EU-type examination route, or unit verification Notified Body? Yes
Two rows deserve attention.
Fact — check it yourself
The “other equipment” row for category 2 is the one nobody expects.
Mechanical equipment in category 2 — a gearbox, a fan, a mixer, a conveyor drive — does not need a Notified Body to assess it, but the technical documentation must be lodged with one, which acknowledges receipt and keeps it. Manufacturers routinely miss this because it is neither self-certification nor certification, and it does not look like either.
Directive 2014/34/EU, art. 13(1)(b)(ii)
Fact — check it yourself
Components follow the same procedures with one important exception: they do not carry the CE marking and do not get an EU Declaration of Conformity.
Instead you issue a written attestation of conformity, stating the component’s characteristics and how it must be incorporated so the finished equipment can comply. If you sell ATEX components into Europe and you have been issuing Declarations of Conformity for them, that is the wrong document.
Directive 2014/34/EU, art. 13(3)
Coming from Class and Division
The mapping between the North American Class/Division system and the European zone system is approximate, and treating it as an equivalence is where projects go wrong.
Broadly, Class I Division 1 covers the ground that Europe splits between Zone 0 and Zone 1, and Class I Division 2 corresponds roughly to Zone 2. The U.S. National Electrical Code also recognises a zone system of its own, which brings the two closer — but “closer” is not “the same.” Protection concepts, marking, temperature classification and the evidence required to support them are all specified differently, and a Division-rated product is not an ATEX product because it is rated for a comparable hazard.
What actually transfers: the physics, your test data, and much of your design rationale. What does not: the certification, the marking, and the conformity route.
What we do
- Hazardous area classification for zones 0, 1, 2 and 20, 21, 22 — including helping your customer produce the classification you need from them.
- Equipment selection and ATEX conformity — matching category, protection concept and temperature class to the declared zone.
- Risk assessment for explosive atmospheres.
- Technical documentation and compliance support.
- Notified Body interface — including the documentation deposit that category 2 mechanical equipment requires.