Can Class I Division 1 approved equipment be used in an ATEX Zone 1?
Abstract
Not legally, unless it is also ATEX compliant. Equipment first placed on the EU market or put into service there, including new or used imports, must meet Directive 2014/34/EU with CE and Ex marking. A US Division 1 listing alone does not count.
Not legally, unless the same item is also ATEX compliant. Any equipment intended for a potentially explosive atmosphere that is placed on the EU market or put into service there for the first time must conform to Directive 2014/34/EU. That includes new or used equipment imported from the United States. It needs the CE marking, the Ex hexagon with group and category, and an EU declaration of conformity. A North American Division 1 listing is not recognised in the EU, however good the equipment is technically.
Short answer
- Product law decides first. Directive 2014/34/EU covers new products made in the EU and new or used products imported from outside the EU when they are first made available or used there.
- Workplace law then decides the category. Under Directive 1999/92/EC, unless the explosion protection document states otherwise on the basis of a risk assessment, Zone 1 needs category 1 or 2 equipment for the right atmosphere (G for gas).
- A Division 1 listing gives no category. Class I, Division 1 covers both Zone 0 and Zone 1 conditions, but its groups (A to D), temperature codes and protection methods do not translate automatically into ATEX categories or EPLs.
- The practical route is an ATEX-certified variant from the manufacturer, which many North American manufacturers offer, or ATEX conformity assessment of the product, which for category 2 electrical equipment involves a notified body.
- Equipment already lawfully in service in the EU is a different case; this answer is about equipment brought in now.
Why the US approval does not count in the EU
The ATEX product directive regulates the moment a product is placed on the EU market or put into service. The Commission's ATEX 2014/34/EU Guidelines (6th edition, January 2026) list what this covers: new products manufactured in the EU, "as-new" products, new or used products imported from a non-EU country, and products relabelled by someone other than the original manufacturer. Putting into service is the first use in the EU by the end user. So importing a unit for your own plant does not avoid the directive.
Conformity is shown only through the directive's own procedures: notified bodies in the EU system, the manufacturer's EU declaration of conformity and the marking set out in Article 16 and Annex II. A Nationally Recognized Testing Laboratory listing is a US workplace approval under OSHA rules. It may rest on similar test methods, but it is not a notified body certificate and does not give the product a CE marking.
Technical differences that matter even with good intentions
| Topic | North American Division 1 | ATEX Zone 1 |
|---|---|---|
| Location covered | Zone 0 and Zone 1 conditions together | Zone 1 only; Zone 0 needs category 1 |
| Gas groups | A, B, C, D (A most severe) | IIA, IIB, IIC (IIC most severe) |
| Temperature marking | T1 to T6 plus sub-codes such as T3C | T1 to T6, or a maximum surface temperature in °C, no sub-codes |
| Equipment rating | Class, division, group, temperature code | Group II, category 2 G, plus standards marking such as Ex db IIB T4 Gb |
| Wiring practice | Often conduit with seals | Usually cable with certified Ex glands |
The group letters run in opposite directions, and the temperature sub-codes have no direct IEC equivalent. A US conduit entry also needs a suitable certified Ex cable gland or adapter before it can be wired to European practice. None of this can be fixed on site by a relabel.
Example: A US-built compressor package arrives for a Zone 1, IIA area in Germany. Its motor and switches are listed for Class I, Division 1, Group D, with NRTL marks, but there is no CE or Ex hexagon on them. The importer cannot put the package into service as it stands. The supplier replaces the motor and switches with ATEX and IECEx dual-certified versions marked, for example, II 2 G Ex db IIB T4 Gb. The package builder then assesses the combination as an ATEX assembly and issues an EU declaration of conformity for it.
Common mistakes
- "Division 1 is stricter than Zone 1, so it is fine." Legally irrelevant, and technically the systems do not map one to one.
- Reading the "unless the explosion protection document states otherwise" clause as an exemption. It concerns the choice of category on the basis of risk. It does not make a non-conforming new product legal to place on the market or put into service.
- Checking only the main item. On a US skid, every motor, switch, junction box, instrument and light needs ATEX conformity.
Related on excodex
- North American hazardous location approvals: NEC 500/505/506, UL, CSA and FM
- Zones vs Divisions: IEC and ATEX zones compared with NEC Class I Division 1 and 2
- ATEX vs IECEx: differences, similarities and which one you need
- Can ATEX or IECEx equipment be used in the United States?
- Does a skid or panel built from ATEX-certified parts need its own ATEX certification?
Standards and further reading
- European Commission, ATEX 2014/34/EU Guidelines, 6th edition (January 2026), sections on placing on the market and putting into service: single-market-economy.ec.europa.eu (PDF)
- Directive 2014/34/EU, Article 16 (CE marking and the specific marking of explosion protection): legislation.gov.uk
- Directive 1999/92/EC, Annex II Part B (selection of equipment by category and zone): legislation.gov.uk
- 29 CFR 1910.307, US workplace rules for hazardous (classified) locations: osha.gov
- NFPA 70, National Electrical Code, Articles 500 and 505
This article is general technical information prepared by the excodex editorial team. It does not replace the applicable standards, the equipment certificates and instructions, national regulations or the assessment of a competent person.