Dust Hazard Analysis (DHA)
Combustible Dust Hazard Assessment
A Dust Hazard Analysis (DHA) is a structured assessment used to identify and evaluate fire and explosion hazards associated with combustible dust.
Dust Hazard Analysis Overview
A DHA examines where combustible dust hazards can occur, how dust clouds or hazardous accumulations may form, what could ignite them, and whether existing prevention and protection measures are adequate.
The assessment considers process equipment, material handling systems, buildings and operating areas during normal operation, start-up, shutdown and credible upset conditions.
The objective is practical: identify credible dust fire and explosion scenarios, evaluate existing safeguards, determine where additional risk reduction is required, and provide a clear basis for managing combustible dust risks.
Regulatory Context
For facilities operating in the European Union, combustible dust hazards fall within the requirements of ATEX Workplace Directive 1999/92/EC (ATEX 153) where explosive atmospheres may occur.
DHA can provide the technical risk assessment basis for Hazardous Area Classification (HAC) and the preparation or update of the facility’s Explosion Protection Document (EPD).
How Dust Hazard Analysis Works
1. Initial Screening
The first step determines whether the materials handled can present a significant combustible dust hazard.
Available dust properties and process information are reviewed, including parameters such as:
- Minimum Ignition Energy (MIE)
- Minimum Explosible Concentration (MEC)
- Kst and Pmax
- Dust cloud and layer ignition temperatures
- Particle size and moisture content
Where reliable data is unavailable, additional dust testing may be recommended.
2. Facility Assessment
Our specialist reviews the process and performs a plant walkthrough to identify where combustible dust may be generated, released or accumulated.
Process equipment, dust collection systems, transfer points, storage areas and buildings are assessed together with existing operating and maintenance practices.
3. DHA Workshop
The DHA is performed together with relevant engineering, operations, maintenance and HSE personnel.
The assessment includes:
- Identification of credible dust fire and explosion scenarios.
- Identification of potential ignition sources.
- Evaluation of existing prevention and protection measures.
- Review of explosion venting, suppression, isolation and containment systems where applicable.
- Assessment of combustible dust accumulation within buildings and process areas.
- Identification and prioritisation of additional risk reduction measures.
4. Reporting and Risk Reduction
The findings are consolidated into a structured Dust Hazard Analysis Report containing identified hazards, scenarios, safeguards and prioritised recommendations.
Where required, the scope can also include Hazardous Area Classification (HAC) and preparation or update of the Explosion Protection Document (EPD).
Deliverables and Client Value
Deliverables
- Dust Hazard Analysis Report.
- Identified combustible dust fire and explosion scenarios.
- Review of existing safeguards and explosion protection measures.
- Ignition source assessment.
- Prioritised risk reduction recommendations.
- Hazardous Area Classification, where included in the scope.
- Explosion Protection Document, where included in the scope.
Value for our Client
- Clear understanding of where combustible dust risks exist and how they are controlled.
- Practical, risk-based recommendations rather than unnecessary capital expenditure.
- Identification of opportunities to reduce risk through engineering, operational, organisational and housekeeping measures.
- A documented technical basis for ATEX 153 compliance and the Explosion Protection Document.
- Improved protection of personnel, equipment and business continuity.
Our process safety specialists can support your team through the complete DHA process — from initial combustible dust screening and site assessment to a practical, documented risk reduction plan.
