ATEX Coating Lines: Explosion-Proof Design Requirements
📅 Published: February 25, 2026
⏱ Reading Time: 13 minutes
✍️ Acrotech Engineering Team
ATEX compliance is not optional — it is a legal requirement for coating facilities in the EU and many other jurisdictions. Powder coating creates combustible dust clouds; wet painting with solvent-based paints creates flammable vapor atmospheres. Both require explosion-proof equipment, proper zone classification, and documented risk assessments.
What is ATEX?
ATEX comes from the French "ATmosphères EXplosibles" and refers to two EU Directives:
- ATEX 2014/34/EU (Equipment Directive): Requirements for equipment used in explosive atmospheres
- ATEX 1999/92/EC (Workplace Directive): Employer responsibilities for protecting workers
In coating operations, ATEX applies to: powder coating booths (combustible dust), wet paint booths (flammable vapors), powder storage areas, paint mixing rooms, and associated ductwork and equipment.
Zone Classification for Coating Facilities
| Zone | Dust/Gas | Duration | Typical Area | Equipment Category |
|---|
| Zone 20 | Dust | Continuous or frequent | Inside powder booths, hoppers | Category 1D |
| Zone 21 | Dust | Occasional (normal operation) | Around booths, sieve area | Category 2D |
| Zone 22 | Dust | Unlikely, short duration | General area near powder equipment | Category 3D |
| Zone 0 | Gas/Vapor | Continuous | Inside solvent tanks | Category 1G |
| Zone 1 | Gas/Vapor | Occasional | Inside wet paint booths | Category 2G |
| Zone 2 | Gas/Vapor | Unlikely, short | Near booth openings, mixing rooms | Category 3G |
Equipment Requirements by Zone
Powder Coating Booths (Zone 20/21)
- All electrical equipment ATEX Category 1D or 2D certified
- Intrinsically safe (Ex ia) or encapsulated (Ex ma) components
- Conductive or anti-static booth walls, flooring, and hoses
- Grounding resistance <1 MΩ for all conductive parts
- Explosion relief venting panels (calculated per EN 14491)
- Automatic powder feed shutdown on ventilation failure
Wet Paint Booths (Zone 1/2)
- Flameproof (Ex d) or increased safety (Ex e) motors and lighting
- Intrinsically safe control circuits in Zone 1
- Continuous LEL (Lower Explosive Limit) monitoring with automatic shutdown at 25% LEL
- Spark-proof fans and ductwork
- Anti-static flooring (conductivity 10⁴-10⁸ Ω)
Ventilation for ATEX Compliance
Key ventilation rules:
- Powder booth: Maintain dust concentration below 50% of Minimum Explosive Concentration (MEC)
- Wet paint booth: Maintain solvent vapor below 25% of LEL at all times
- Ventilation system must start before any coating operation begins
- Interlock: Coating equipment cannot operate without confirmed air flow
- Emergency ventilation must be able to purge 5× booth volume
Documentation Requirements
- Explosion Protection Document (EPD): Mandatory risk assessment per ATEX 1999/92/EC
- Zone classification drawings: Marked floor plans showing all classified zones
- Equipment register: All ATEX-rated equipment with certificates and categories
- Maintenance records: Scheduled inspections per manufacturer guidelines
- Training records: All personnel trained in ATEX awareness and emergency procedures
⚠️ Non-compliance consequences: Insurance invalidation, facility closure orders, personal criminal liability for facility managers, and most critically — the risk of explosion causing injury or death.
All Acrotech coating plants are designed for ATEX compliance. Our
powder coating plants and
wet painting facilities include ATEX-certified components, proper zone classification engineering, and complete documentation packages.