Employer Duties Under ATEX
Employer Duties Under ATEX
The ATEX Workplace Directive (1999/92/EC) places clear duties on employers wherever workers may be exposed to explosive atmospheres. These aren't optional guidelines—they're legal requirements backed by national enforcement and penalties. Understanding what's required is the first step to compliance, and Article 3 of the directive lays out a structured approach that every employer must follow.
The Hierarchy of Prevention
The directive establishes a priority order that employers must work through sequentially—you don't get to pick the option that's most convenient:
- First priority: Prevent the formation of explosive atmospheres entirely—through substitution of flammable materials, process modification, or containment
- Second priority: Where prevention isn't possible, avoid ignition of any explosive atmosphere that does form—through equipment selection, earthing, and elimination of ignition sources
- Third priority: Mitigate the effects of any explosion to protect worker health and safety—through explosion relief, suppression, or isolation systems
Many workplaces jump straight to "use ATEX equipment" when better ventilation or process changes could reduce or eliminate the hazard altogether. The directive requires you to genuinely consider prevention before moving to the more expensive options.
Risk Assessment
Article 4 requires employers to assess explosion risks, considering the likelihood that explosive atmospheres will form and persist, the likelihood that ignition sources will be present and active, the installations and substances involved, and the scale of anticipated effects. This risk assessment must be documented and reviewed whenever the workplace, equipment, or work organisation undergoes significant changes.
The assessment isn't a one-time exercise. A new process, a relocated tank, a different raw material, or even a change in operating hours could invalidate previous assessments.
Zone Classification
Article 7 requires employers to classify places where explosive atmospheres may occur into zones. This classification is the bridge between risk assessment and equipment selection—the zone determines what category of equipment must be used in each area. Getting classification wrong means either over-specifying expensive equipment or, far more dangerously, using equipment that isn't safe for the actual conditions.
Where necessary, areas where explosive atmospheres may occur must be marked with warning signs at entry points—the EX warning triangle on a yellow background.
The Explosion Protection Document
Article 8 requires employers to prepare and maintain an Explosion Protection Document (EPD). This document must demonstrate that explosion risks have been assessed, adequate protective measures will be taken, zones have been classified, and work equipment is designed and maintained with safety in mind. The EPD must exist before work commences and be revised when significant changes occur.
Equipment Requirements
Employers must ensure that work equipment in hazardous areas meets the directive's minimum requirements. Equipment installed after June 2003 must comply with the ATEX Equipment Directive's marking requirements—meaning it must carry appropriate CE and ATEX marking for the zone it's installed in. All equipment must be properly maintained throughout its operational life, with systematic inspection programmes to verify ongoing safety.
Coordination with Other Employers
When workers from multiple employers are present at the same workplace—which is common when contractors are involved—Article 6 requires the employer responsible for the site to coordinate safety measures. This coordination must be documented in the EPD, including specific procedures for how it works in practice. The presence of contractors doesn't reduce anyone's responsibilities; if anything, it increases them because of the additional communication and supervision challenges.
Worker Training and Information
Employers must provide workers with sufficient and appropriate training about explosion risks and the measures taken to protect them. Workers need to understand which areas are classified, what the warning signs mean, what they must and must not do in hazardous areas, and what to do in an emergency. Training should be given before work begins in classified areas and refreshed when conditions or procedures change.
