HSE Principle: “Preventing explosions = identifying + controlling explosive atmospheres”

ATEX Regulation (Explosive Atmospheres)

EU Directive 2014/34/EU (equipment) + 1999/92/EC (workplaces), transposed in France by Decree 2015-799 and the Labor Code.
Objective: Eliminate ignition risks in areas with explosive atmospheres (gases, vapors, dusts).[1][2][3]

Step 1: Risk Assessment and Zoning

Employer obligation: Conduct a comprehensive risk analysis (DUERP including ATEX) to identify:

• Combustibles: flammable gases, vapors, dusts
• Oxidants: O₂ > 11%, atmospheric pressure
• Sources of ignition: sparks, flames, hot surfaces

Zone classification (based on frequency/duration of explosive atmosphere):

Gases / Vapors	Dusts	Likelihood
Zone 0	Zone 20	Permanent (>1000 h/year)
Zone 1	Zone 21	Occasional (10–1000 h/year)
Zone 2	Zone 22	Accidental (<10 h/year)

Zoning is indicated by regulatory signs and documented in the Explosion Protection Document (DPE).

Step 2: Preventive Measures (Hierarchy)

1. Prevent formation of explosive atmospheres
   • Capture dust/vapor sources
   • Inerting (N₂ / CO₂)
   • Increase dust particle size
2. Prevent sources of ignition
   • ATEX-certified equipment (marking Ex II 2G)
   • Static controls (grounding)
   • Prohibitions (smoking, non-ATEX tools)
3. Limit effects of an explosion (if 1 and 2 are not possible)
   • Explosion vents
   • Explosion suppression
   • Compartmentalization

Step 3: Equipment Requirements (Directive 2014/34/EU)

• Mandatory marking: Ex + explosion symbol + group (I/mines, II/surface) + category (1/2/3)
• Certification: notified body for zones 0/20/1/21
• Documentation: instructions, technical file (retain 10 years)
• 2026: 5th edition ATEX Guide + alignment with Machinery Regulation 2023/1230 (electronic documentation allowed)[1]

Step 4: Organization and Training

• Worker training: adapted to zone/exposure (ATEX safety training, hot work permits)
• High-risk work: written instructions, fire permit system
• Clothing: anti-static (EN ISO 11612)
• Maintenance: periodic checks of ATEX equipment

Audit and Compliance 2026

By 30 May 2026: full transposition of the revised ATEX Directive. Required actions:

• Verify existing equipment (re-certify if needed)
• Update DPE and zoning
• Refresher training + evacuation drills
• Supplier audits (ensure ATEX certificates are current)