ATEX Control Cabinet Design Guide | Zones & Compliance

An “ATEX control cabinet” is not created by putting ordinary controls into a stainless box and adding an Ex label. Compliance depends on the intended atmosphere, zone, equipment category, gas or dust group, temperature class, ambient range, protection concept, installed components and the way the completed assembly is assessed.

The enclosure still matters. Material, joints, cable entries, bonding, sealing, heat dissipation and mechanical strength can determine whether the selected protection concept works. But the sheet metal enclosure is one part of a larger explosion-safety and conformity system.

If the hazardous-area architecture is already defined and you are sourcing build-to-print metalwork, review our ATEX control cabinet metalwork manufacturer and RFQ scope. This guide addresses design and conformity questions rather than replacing the equipment manufacturer’s assessment.

What ATEX means for a control cabinet

Two EU directives are commonly discussed together:

• ATEX product Directive 2014/34/EU covers equipment and protective systems intended for potentially explosive atmospheres and sets essential health and safety requirements plus conformity-assessment obligations before products are placed on the EU market.
• ATEX workplace Directive 1999/92/EC addresses employer responsibilities, including hazardous-place classification and the safe selection and use of equipment.

The current consolidated text of Directive 2014/34/EU is the legal starting point for the product. The European Commission’s sixth-edition ATEX Guidelines, issued in January 2026, explain how the Directive is applied, including combined equipment and assemblies.

This distinction matters in a sourcing project. The site operator classifies the hazardous area and defines the operating conditions. The product manufacturer uses that input to design and assess the cabinet or assembly. A fabricator cannot determine the correct category from the words “ATEX cabinet” alone.

Zones and equipment categories

The workplace Directive classifies hazardous places by how often and how long an explosive atmosphere is present.

Atmosphere	Zone	Definition in practical terms	Equipment category normally selected*
Gas, vapour or mist	0	Present continuously, for long periods or frequently	Category 1G
Gas, vapour or mist	1	Likely to occur occasionally in normal operation	Category 1G or 2G
Gas, vapour or mist	2	Not likely in normal operation; if it occurs, it persists briefly	Category 1G, 2G or 3G
Combustible dust cloud	20	Present continuously, for long periods or frequently	Category 1D
Combustible dust cloud	21	Likely to occur occasionally in normal operation	Category 1D or 2D
Combustible dust cloud	22	Not likely in normal operation; if it occurs, it persists briefly	Category 1D, 2D or 3D

*The workplace explosion-protection document and risk assessment govern the final selection. The zone-category relationship comes from Directive 1999/92/EC.

The zone is not enough. A cabinet specification also needs the substance and its classification, gas or dust group, required temperature class or maximum surface temperature, ambient-temperature range and other site conditions. Gas and dust duties are not interchangeable.

Information required before enclosure design

Request these inputs from the site or system owner:

• Gas, vapour, mist or combustible-dust duty.
• Zone and required equipment category or EPL.
• Gas group or dust group.
• Temperature class or permitted maximum surface temperature.
• Minimum and maximum ambient temperature.
• Indoor or outdoor exposure, washdown, salt, chemicals, UV and impact risk.
• Heat dissipation of installed equipment and available cooling method.
• Cable types, sizes, armour, entry direction and gland schedule.
• Required ingress protection and corrosion life.
• Whether the deliverable is an empty component enclosure, populated cabinet, combined assembly or site installation.

Without these, an enclosure supplier can discuss manufacturability but cannot responsibly confirm suitability.

Select the protection concept before the box

ATEX identifies essential requirements; harmonised EN standards provide technical routes that may give presumption of conformity for the requirements they cover. The applicable standard set depends on the protection concept and equipment.

Common approaches for control equipment include:

• Flameproof enclosure, Ex d - the enclosure withstands an internal explosion and prevents flame transmission through controlled joints. Machining, joints, fasteners, entries and internal contents are tightly controlled. It is not simply a thick IP-rated cabinet.
• Increased safety, Ex e - design prevents arcs, sparks and excessive temperatures in normal service and under defined abnormal conditions. Terminals, clearances, creepage, connections and enclosure performance are part of the assessment.
• Pressurization, Ex p - protective gas maintains the required pressure and may require purge cycles, monitoring and automatic actions. Leakage, door interlocks and control-system behavior are central.
• Intrinsic safety, Ex i - circuit energy is limited so ignition cannot occur under the assessed conditions. Barriers, segregation, wiring and entity parameters matter; an ordinary enclosure does not create intrinsic safety.
• Protection by enclosure for dust, Ex t - dust ingress and surface temperature are controlled by the enclosure system and its installed entries, joints and thermal behavior.

One cabinet may use more than one protection concept. That makes interface control essential. The project engineer should identify the exact standards and certificate conditions for the chosen architecture, using the Commission’s current ATEX harmonised-standards list.

Enclosure material selection

ATEX does not prescribe stainless steel for every cabinet. Choose material from corrosion, impact, electrostatic, temperature, weight and fabrication requirements.

Material	Where it can fit	Design cautions
Powder-coated carbon steel	Indoor or controlled environments with a qualified coating system	Damage, cut edges and condensation can initiate corrosion; maintain bonding at masked interfaces
304 stainless steel	General industrial and cleanable environments	Check chloride and chemical exposure; remove fabrication contamination and restore the specified finish
316L stainless steel	Coastal, chemical, washdown and corrosive service	Higher cost; weld distortion and heat tint still require control
Aluminum	Weight-sensitive or corrosion-resistant enclosure systems	Confirm alloy, impact duty, thread durability, galvanic isolation and electrostatic requirements
GRP or engineered polymer	Corrosive duty and electrical isolation where the certified design permits	Electrostatic charging, UV, impact, flame behavior and temperature limits need assessment

Stainless steel resists corrosion; it does not make a cabinet explosion-proof. Conversely, a properly assessed coated-steel design may be suitable for a defined duty. Material must be consistent with the certified or assessed enclosure construction.

For outdoor corrosion strategy, see our outdoor enclosure corrosion guide and 304 vs 316 comparison.

Mechanical details that affect compliance

Doors, joints and fasteners

Door geometry must maintain the protection concept after fabrication, finishing, repeated access and service. Control:

• Flange flatness and joint geometry.
• Hinge alignment and door sag.
• Latch position and repeatable compression.
• Fastener grade, spacing and retention.
• Unauthorized opening or safe-opening provisions where required.
• Surface damage, weld spatter and coating buildup at critical interfaces.

For Ex d equipment, flamepaths are safety-critical machined features governed by the certified design and applicable standard. They cannot be treated like ordinary gasket flanges, repaired casually or modified in the field without review.

Gaskets and ingress protection

An IP rating and an ATEX protection concept answer different questions. IP addresses ingress of solids and water under specified tests. ATEX addresses ignition risks in an explosive atmosphere. Some concepts depend on enclosure ingress performance, but an IP66 enclosure is not automatically ATEX compliant.

Specify gasket material for temperature, compression set, chemicals and service life. Use a continuous, controllable compression path and verify corners, splices, hinges and cable-entry zones. Our IP ratings guide and waterproof enclosure sealing guide cover the underlying enclosure details.

Cable entries

Cable glands, conduit entries, stopping plugs and adapters must match the protection concept, cable construction, thread, environment and certificate conditions. The gland plate is not a blank area that can be drilled freely at site.

The 2026 Commission Guidelines specifically warn that an empty Ex d enclosure requiring later drilling and assembly may be a component rather than completed equipment; machining and installed entries can require further assessment and tests. Define entry quantity, thread form, spacing, cable diameter, armour and sealing method before release.

Bonding and electrostatic control

Doors, removable panels, gland plates and mounting plates may need deliberate protective bonding. Do not rely on hinges, paint-cutting washers or incidental metal contact unless the assessed design permits it.

Provide controlled bare-metal interfaces, bonding studs and conductors sized for the electrical and mechanical duty. Protect the contact zone from paint and corrosion, and include continuity checks in production where specified. Non-metallic surfaces and coatings also require electrostatic assessment for the intended atmosphere.

Thermal management

The temperature class or maximum surface-temperature limit applies to the completed operating equipment, not the empty cabinet. Heat comes from drives, power supplies, terminals, barriers, contactors, heaters and solar load. A sealed enclosure can trap that heat.

Create a thermal model or validated test plan using:

• Worst-case internal dissipation.
• Maximum specified ambient temperature.
• Solar loading for outdoor cabinets.
• Component derating and spacing.
• Allowed surface-temperature limit.
• Protection-concept restrictions on ventilation or cooling.
• Failure behavior of fans, purge or cooling controls.

Ordinary filtered vents cannot be added to solve a late thermal problem if they violate the protection concept or ingress requirement. See our enclosure cooling guide for the general heat-balance method.

Components do not automatically make a compliant assembly

Using individually compliant glands, terminals, switches and enclosures is necessary in many architectures, but the final combination can introduce new ignition hazards or change temperature, ingress, spacing and protection performance.

The Commission’s 2026 ATEX Guidelines explain that a combined product placed on the market as a single functional unit has a responsible manufacturer. That manufacturer may rely on the conformity of already assessed items, but must evaluate hazards introduced by the final combination. If additional ignition hazards arise, further conformity assessment is required for the assembly.

This is especially important when an OEM buys:

• An empty enclosure from one supplier.
• Glands and Ex components from several manufacturers.
• Mechanical integration from a contract fabricator.
• Wiring and programming from a panel shop.
• Final installation from a site contractor.

The project still needs one clearly identified legal manufacturer for the product placed on the market, plus an agreed boundary between product assembly and site installation.

Conformity assessment and documentation

The applicable conformity route depends on equipment group, category, type of equipment and chosen module. Some routes require a notified body; others use internal production control, and alternatives such as unit verification may be available. Do not assume that every Zone 2 cabinet needs the same route or that every component certificate covers the completed cabinet.

A typical product-compliance package may include:

• Defined intended use and equipment classification.
• Ignition-hazard and conformity assessment.
• Drawings, calculations and BOM.
• Certificates and instructions for incorporated equipment and components.
• Special conditions of use carried into the final design.
• Applied standards and controlled deviations.
• Thermal, ingress, impact, bonding or other required test evidence.
• Manufacturing and inspection records.
• Marking design.
• Instructions for installation, operation and maintenance.
• EU declaration of conformity for the completed product, where applicable.

The Directive requires manufacturers to retain the EU declaration and technical documentation for the specified period. The exact file content and notified-body involvement should be set with a qualified explosion-protection specialist early in the program.

Common ATEX cabinet specification mistakes

Avoid these recurring errors:

1. Asking for “ATEX certified” without zone, substance group, temperature or ambient data.
2. Treating IP66, NEMA 4X and ATEX as interchangeable labels.
3. Selecting stainless steel as the protection concept.
4. Installing certified components without assessing the completed combination.
5. Drilling new cable entries without checking the enclosure and gland conditions.
6. Ignoring internal heat dissipation and maximum ambient temperature.
7. Coating over bonding interfaces or critical joints.
8. Allowing component substitutions without certificate and thermal review.
9. Leaving legal-manufacturer responsibility undefined across multiple suppliers.
10. Assuming a voluntary document is equivalent to a certificate issued under the applicable EU conformity route.

The European Commission also warns that unregulated or voluntary certificates can be misleading. Verify notified-body scope through the official systems where notified-body involvement is required.

RFQ checklist for an ATEX control cabinet

Provide the following before requesting a production quote:

• Zone, gas/dust duty, group and equipment category or EPL.
• Temperature class or maximum surface temperature.
• Ambient and environmental conditions.
• Protection concept and governing standard set.
• Cabinet schematic, GA drawing, heat-load schedule and cable-entry plan.
• Approved components with certificates and special conditions of use.
• Enclosure material, finish, IP requirement and corrosion target.
• Assembly, wiring and testing boundary for each supplier.
• Legal manufacturer and conformity-assessment plan.
• Required inspection records, serial traceability and documentation language.
• Installation and maintenance constraints.
• Target volume, variants and change-control process.

This information lets a fabricator review enclosure manufacturability without making unsupported assumptions about hazardous-area suitability.

How DRAmetal supports ATEX enclosure programs

DRAmetal manufactures drawing-based ATEX control cabinets, general industrial control cabinets, electrical enclosures and related sheet metal assemblies. Our fabrication scope can include material traceability, cutting, forming, welding, finishing, gasket and hardware installation, defined bonding features, dimensional inspection and controlled packout.

For hazardous-area projects, we work to the released enclosure design, component constraints, inspection plan and conformity responsibilities established by the equipment manufacturer and its explosion-protection specialists. We do not treat material choice or IP testing alone as proof of ATEX compliance.

If you have a defined ATEX cabinet architecture and need a production enclosure partner, send us the drawings, classification data, component schedule and annual volume. We will review fabrication risks, cable-entry feasibility, sealing surfaces, thermal constraints and the records required from the manufacturing process.

For related reading: control-cabinet corrosion protection, material traceability, sheet metal assembly and integration, and supplier factory audits.

This article provides general engineering information and is not a substitute for project-specific explosion-risk assessment, standards review or legal advice.