What Is It?
DSEAR Risk Assessment and Hazardous Area Classification (HAC) are broadly recognised techniques used for assessing the risk from dangerous substances within the workplace. These techniques define the locations where a potentially explosive atmospheres may occur, evaluate the associated risks, and define suitable controls measures.
Under the Dangerous Substances and Explosive Atmospheres Regulations (DSEAR) and the ATEX Directives, employers must identify explosion and fire risks arising from dangerous substances and ensure that control, mitigation, and zoning measures are implemented and maintained.
A combined DSEAR and HAC service provides a structured, evidence-based assessment aligned with HSE ACOP L138, Industry Codes of Practice, and the IEC standards.
Who Needs It?
This service supports organisations handling, storing, or processing flammable gases, vapours, or dusts , including:
– Refineries and petrochemical facilities
– Power generation and energy storage installations (BESS)
– Chemical and pharmaceutical manufacturing
– Water and wastewater treatment sites
– Food and beverage plants with combustible dust risks
Those responsible for ensuring compliance with DSEAR and ATEX requirements in either initial DSEAR Risk Assessment and HAC or review and update to existing assessments.
Why Does It Matter?
Accurate DSEAR risk assessment and classification are essential to prevent ignition incidents and demonstrate compliance with UK law. When assessments are incomplete or outdated, sites may face:
- Incorrect zoning or equipment selection, increasing explosion risk
- Non-compliance with DSEAR, IEC 60079-10, and 60079-14
- Unnecessary or costly design rework due to misclassification
- Regulatory and insurance challenges during audits or incident investigations
Best practice — as set out in HSE guidance L138 — emphasises that risk assessment, classification, and verification should be integrated and periodically reviewed to ensure ongoing suitability.
Our Approach
Our team of engineers apply a structured methodology consistent with IEC 60079-10-1 (gases and vapours), IEC 60079-10-2 (dusts), and HSE ACOP L138 along with other industry codes of practice such as EI 15 and IGEM/SR/25. Our combined DSEAR and HAC process includes:
– Data Gathering – Review of substances, process conditions, and ventilation data.
– Hazard Identification – Identification of flammable or explosive materials and ignition sources.
– Release Analysis – Evaluation of potential release points and frequency.
– Zone Extent Determination – Calculation or estimation of zone dimensions using recognised models.
– Risk Evaluation – Assessment of explosion risk considering existing control and mitigation measures.
– Drawing Production – Development or verification of hazardous area classification diagrams.
– Action Planning – Prioritised recommendations to close compliance gaps.
– Integration with Verification – Cross-check with equipment inspection and maintenance regimes.
All findings are clearly documented in a defensible report that supports compliance, operational safety, and audit readiness.
Outcome
A complete and traceable record of compliance that includes:
- Hazardous area classification drawings.
- DSEAR risk assessment aligned with HSE and IEC standards.
- Prioritised recommendations for control and mitigation measures.
- Evidence suitable for regulatory or insurance review.
Water - Area Manager
“The E-learning is a great alternative to travelling to a classroom. We were able to sit the training while we waited for the weather to clear up. The team are very helpful, it was nice to be able to pick up the phone and speak to a real person – Thanks for your help Clio!”
Related Services
- Classroom
- Certified
- On-site
- Classroom
- Certified
- On-site
Benefits for Learners and Managers
- Foundation for safety culture: Establishes a common language and awareness of process safety across the workforce.
- Improved compliance: Supports regulatory requirements and industry standards set by the PSMCPB.
- Flexibility in delivery: Choose between direct delivery or train‑the‑trainer licensing to suit organisational needs.
- Reduced risk of incidents: Ensures staff understand their role in preventing accidents and responding effectively when things go wrong.
Course Content
- Introduction to process safety – definitions, key concepts and differentiation from occupational safety.
- Legislation and standards – overview of health and safety legislation relevant to high‑hazard industries.
- Hazard and risk identification – tools and techniques for recognising hazards and assessing risks.
- Mitigation measures and emergency response – understanding available mitigation measures and the role of emergency response.
- Consequences of process safety failures – case studies and workshop activities illustrating real-world impacts.
Key Information
Useful Information
- Service: DSEAR Risk Assessment & Hazardous Area Classification
- Standards: HSE L138, EI 15, IEC 60079-10-1 / -10-2, IEC 60079-14
- Outputs: DSEAR risk report, hazardous area classification drawings, and action plan
- Linked Regulation: DSEAR / ATEX
- Review Frequency: Every 3–5 years or following process modification
Who We Work With
- COMAH and high-hazard site operators
- Engineering and process safety teams
- Electrical, instrumentation, and control engineers
- Project and maintenance teams requiring verification and compliance
Common Triggers for Review
- Process or plant modification
- New or substituted substances
- Ventilation or containment changes
- Audit findings or equipment upgrades
- Regulatory or insurer requests
Deliverables
- Combined DSEAR and HAC report
- Zone drawings and supporting data
- Clear, traceable justification for classification decisions
- Recommendations for compliance improvement
FAQs
It’s an evaluation of explosion and fire risks from dangerous substances, considering the likelihood of formation and ignition of explosive atmospheres.
HAC defines the extent and likelihood of explosive atmospheres (zones), forming the technical foundation for equipment selection and control measures under DSEAR and is specified as a requirement under Reg 7
Assessments follow HSE L138, IEC 60079-10-1/-10-2, IEC 60079-14, and Industry codes of practice such as Energy Institute EI 15 and IGEM/SR/25.
After a “suitable period of time”. This typically means every three to five years, or whenever changes occur to processes, substances, or ventilation systems. We often provide competent resource to attended site and walk through the requirements to ensure that everything is up to date and that any onsite changes have been adequately included in the site documentation.
Process and instrumentation diagrams (P&IDs), site layout and ventilation drawings, Material Safety Data Sheets (MSDS), equipment lists, maintenance records, and access to operational and maintenance teams.
Yes. Ecfio frequently audits or updates older DSEAR and HAC reports to align with current best practice and correct inconsistencies in classification or documentation.
A clear scope and methodology, hazard identification and zone classification data, calculations or engineering justification for zoning, recommendations for improvements, and drawings suitable for engineering and inspection use.
Any workplace where flammable gases, vapours, or dusts are present — including energy, chemicals, manufacturing, utilities, food and drink, and waste management sectors.
We will hold a handover meeting in which we will provide a prioritised action plan with clear responsibilities, helping clients update drawings, verification records, and maintenance systems to ensure ongoing compliance.
To discuss your current DSEAR and HAC status or schedule a site review:
📧 support@ecfio.co.uk | 📞 +44 (0) [insert number]