ATEX Risk Assessment

ATEX Risk Assessment

An ATEX Risk Assessment identifies where explosive atmospheres can form, how ignition could occur, and which measures are needed to prevent explosions and protect people and assets.

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ATEX Risk Assessment

The assessment is structured so that non-specialists can follow each step. Hazards are translated into clear decisions and actions, bringing together hazardous area classification, ignition source control, and equipment selection in one coherent view.

The outcome is defensible, audit-ready, and practical to implement, providing clarity on priorities, regulatory compliance, and a focused action plan.

ATEX Risk Assessment Background and Regulatory Context

The ATEX Workplace Directive 1999/92/EC requires employers to assess explosion risks and classify places into zones. It also requires an Explosion Protection Document (EPD) to be prepared before work starts and kept up to date.

The directive sets selection rules for equipment by zone and requires verification of overall explosion safety by a competent person before a hazardous workplace is first used.

The ATEX Equipment Directive 2014/34/EU governs conformity of Ex equipment and protective systems, and relies on risk assessment and zoning to define the necessary equipment categories/EPLs.

Hazardous Area Classification typically follows:

  • IEC 60079-10-1 for gases/vapours, and
  • IEC 60079-10-2 for dusts,

which define how zones and extents are determined.

Electrical selection and installation interface with IEC 60079-14, while inspection and maintenance align with IEC 60079-17. Ignition source control follows EN 1127-1, with electrostatic guidance from IEC/TS 60079-32-1.

In the UK, DSEAR introduces similar duties to assess and control fire and explosion risks.

How ATEX Risk Assessment Works – Step by Step

  1. Scope and Inputs

The work begins with a clear definition of what the assessment will cover:

  • Aligning on sites, substances, and boundaries.
  • Collecting drawings, PFDs/P&IDs, layouts, ventilation data, operating modes, and maintenance context.
  • Confirming the governing framework: ATEX/IEC and, where relevant, DSEAR.
  • Agreeing risk criteria, data sources, roles, agenda, and the action tracking approach.

This creates a shared basis for the technical work and for later decisions.

  1. Hazardous Area Classification (HAC)

The next step is to establish where explosive atmospheres may occur:

  • Identifying sources of release and assessing ventilation conditions.
  • Determining Zones 0/1/2 for gases and Zones 20/21/22 for dusts.
  • Sizing zone extents using recognized methods and recording key assumptions.
  • Capturing gas group and temperature class for equipment selection interfaces.

Classification can be developed within the assessment or integrated with an existing HAC study.

  1. Ignition Source Analysis

Once zoning is defined, credible ignition sources are reviewed:

  • Listing possible ignition sources in line with EN 1127-1.
  • Evaluating hot surfaces, electrical equipment, mechanical friction, and human activities.
  • Addressing static electricity using measures consistent with IEC/TS 60079-32-1.
  • Documenting existing controls and residual risks in clear language.

This step ensures that both permanent and task-related ignition sources are covered.

  1. Risk Evaluation and Measures

Scenarios are then evaluated and risk reduction measures are defined:

  • Rating scenarios using your risk matrix.
  • Applying the hierarchy of controls: eliminate, prevent, protect, and manage.
  • Identifying prevention measures such as inerting, ventilation, and leak reduction.
  • Defining protection measures such as explosion venting, isolation, or suppression, as appropriate to the equipment and standards.
  • Specifying operational controls: training, permits-to-work, signage, and emergency measures required by ATEX.

The result is a balanced set of technical and organisational measures, with clear rationale.

  1. Equipment Selection and Integration

Zoning and risk measures are then linked to equipment decisions:

  • Mapping zones to equipment requirements and EPL/category.
  • Referencing IEC 60079-14 for electrical design and installation.
  • Noting non-electrical requirements using ISO/IEC 80079-36/37 where relevant.
  • Defining data needs for procurement and vendor documentation.

This allows engineering and procurement teams to apply ATEX requirements consistently.

  1. Inspection, Maintenance, and Lifecycle

The assessment also considers how explosion safety is maintained over time:

  • Setting inspection grades and intervals in line with IEC 60079-17.
  • Specifying proof testing and housekeeping measures where dust layers are credible.
  • Defining change triggers that require re-review and linking them to MOC.
  • Aligning revalidation with the internal PSM cycle.

This embeds ATEX obligations into existing asset and risk management processes.

  1. Documentation and EPD

Finally, the results are documented in a form suitable for internal use and external audit:

  • Compiling a Basis of Assessment and all underpinning assumptions.
  • Assembling the Explosion Protection Document (EPD) with zoning, measures, responsibilities, and verification notes.
  • Preparing an executive summary for leadership and auditors.
  • Briefing stakeholders so that engineering, operations, and HSE work from a single, shared picture.
  • Supporting the required initial verification by a competent person before first use.
RISK management
RISK assessment

Deliverables and Client Value

Deliverables

  • ATEX Risk Assessment Report with scope, method, and results.
  • Hazardous Area Classification summary and drawings, or a clear interface to an existing HAC.
  • Ignition source register with controls and residual risks, aligned with EN 1127-1.
  • Equipment selection guidance referencing IEC 60079-14 and ISO/IEC 80079-36/37.
  • Explosion Protection Document (EPD), ready for sign-off and audits.
  • Action register with owners, priorities, and due dates.
  • Revalidation plan and change trigger checklist.

Client Value

  • A legally compliant assessment recognised by regulators and auditors.
  • Faster, safer equipment selection and control of work in hazardous areas.
  • Fewer late design changes and smoother commissioning.
  • A common risk picture across engineering, operations, and HSE.
  • Confidence that the assessment method follows recognised good practice.

Our experts will provide an initial consultation and support your team through SIL Determination — from selecting scenarios and methods to delivering a practical, compliant set of SIL targets.

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