Who Can Conduct a Dust Hazard Analysis?
A practical guide to selecting the most appropriate
DHA approach for your facility
Facilities that manufacture, process, handle, or store combustible particulate solids need to understand where fire and explosion hazards may exist. A dust hazard analysis (DHA) provides a systematic method for identifying these fire and explosion hazards, evaluating existing safeguards, and determining where additional controls may be required. A DHA must be performed or led by a qualified person with appropriate knowledge and experience in combustible dust hazards, whether that expertise comes from a specialized third-party consultant, such as Sigma-HSE, or from internal personnel with demonstrated competency.
For facility managers, EHS leaders, and other professionals responsible for combustible dust compliance, this qualification question affects NFPA and OSHA exposure as well as the effectiveness of the assessment itself. Simply assigning the analysis to an employee with a safety title or engineering credential does not necessarily establish the specialized competency needed to lead the assessment. NFPA guidance emphasizes relevant education, professional standing, practical dust hazard analysis experience, knowledge of combustible dust standards, and familiarity with the affected processes and materials.
This article explains who can conduct a dust hazard analysis, what qualifications the lead assessor and team should have, how site assessments, laboratory testing, and risk analysis fit into the process, and where training supports long-term combustible dust safety.
Sigma-HSE provides Dust Hazard Analysis consulting supported by combustible dust laboratory testing, process safety expertise, and implementation assistance to help facility leaders move from hazard identification to technically supported corrective actions.
This article examines both approaches, compares their applications, and provides guidance on selecting the right methodology for your facility.
This article covers the following topics:
What Is a Dust Hazard Analysis?
Why Dust Hazard Analysis Methodology Matters
How NFPA 660 Addresses Dust Hazard Analysis
The Prescriptive DHA Method
The Performance-Based DHA Method
Prescriptive vs. Performance-Based DHA: Key Differences
When Each Approach Is Appropriate
Can Both Approaches Be Used Together?
Combustible Dust Hazard Analysis Responsibility
A dust hazard analysis identifies and evaluates credible fire, flash fire, and explosion scenarios associated with combustible dust. The facility owner or operator is responsible for ensuring that the required DHA is completed, while a qualified person must perform or lead the analysis.
NFPA 660 now consolidates combustible dust requirements previously addressed through NFPA 652 and several commodity-specific standards. NFPA 660 requires DHAs for applicable new and existing processes and facility compartments.
Organizations can use qualified internal personnel, outside consultants, or a combination of both. For complex processes, uncertain dust characteristics, or facilities without substantial in-house combustible dust expertise, engaging a specialized third-party consultant, such as Sigma-HSE, can provide the technical leadership needed to conduct and document the analysis.
When Is Dust Hazard Analysis Required by NFPA and OSHA?
NFPA 660 requires a DHA for applicable new and existing processes and facility compartments where combustible or explosible materials are present in an enclosure. The standard also specifies that the absence of previous incidents is not a valid reason for forgoing a DHA. The analysis must be reviewed and updated at least every five years. Changes to materials, equipment, operating conditions, or processes may also require facilities to reevaluate combustible dust hazards through management-of-change procedures. OSHA enforcement may draw on applicable NFPA standards and recognized and generally accepted good engineering practices when evaluating combustible dust conditions.
Sigma-HSE provides combustible dust assessments and gap analyses that benchmark operations against applicable NFPA and OSHA requirements.
Assembling the DHA Team
Although a qualified person leads the DHA, an effective assessment typically benefits from a multidisciplinary team. Operations and maintenance personnel can explain actual equipment operation, cleaning practices, process deviations, and maintenance history. Engineering personnel contribute information about equipment design and safeguards, while EHS professionals provide insight into procedures, training, and compliance programs. Process owners help document how materials move through the facility.
NFPA guidance specifically identifies potential team expertise in operations, maintenance, process equipment, safety systems, material properties, operating history, and emergency procedures.
Sigma-HSE specialists can supplement this facility knowledge with combustible dust testing, hazard analysis, and explosion protection expertise.
Site Assessment Process
A DHA typically includes a detailed review of the process and an on-site assessment. The team identifies locations where dust is generated, conveyed, collected, processed, or stored. Equipment and locations such as dust collectors, mills, dryers, conveyors, silos, mixers, and transfer points require careful evaluation. The team identifies credible ignition sources, combustible dust accumulations, enclosed or confined areas, and conditions capable of producing primary or secondary explosions.
Depending on the process and potential consequences, more detailed modeling may be appropriate to understand explosion scenarios and evaluate proposed protection measures.
Laboratory Testing
Reliable material data is essential to a technically defensible combustible dust hazard analysis. When dust properties are unknown, an initial Go/No-Go explosibility test can determine whether a material is capable of producing a dust explosion under defined test conditions. If the material is explosible, additional testing may be necessary.
Common tests include:
- Kst and Pmax for explosion severity
- Minimum Ignition Energy (MIE)
- Minimum Explosible Concentration (MEC)
- Minimum Ignition Temperature Cloud (MIT Cloud)
- Minimum Ignition Temperature Layer (MIT Layer)
- Limiting Oxygen Concentration (LOC)
Sigma-HSE operates accredited laboratory facilities and provides NFPA-referenced combustible dust testing using recognized ASTM and international methods. Our testing services can generate the material-specific data needed to support the DHA and subsequent engineering decisions, including MEC values that establish the concentration at which a dust cloud becomes explosible and MIT values that establish the temperatures at which ignition can occur.
Facilities can work with Sigma-HSE to select representative samples and obtain appropriate collection, packaging, and shipping instructions before testing. Samples should be representative of the process material and tested in the as-received condition, and some powders require additional evaluation of thermal stability and electrostatic behavior.
Risk Analysis, Modeling, and Prioritization
Once hazards are identified, the DHA team evaluates credible scenarios and existing safeguards. Risk-based approaches may consider both the potential consequences and likelihood of an event, including whether credible ignition sources are present.
Kst, Pmax, and other laboratory data can support quantitative consequence modeling where warranted. Findings can then be ranked so that higher-priority deficiencies receive appropriate attention and shorter implementation timelines. The objective is an actionable plan that connects identified explosion hazards with technically appropriate safeguards.
Training Services
Completing the DHA is only part of the process. Training reduces dust-related fire and explosion risk by ensuring workers understand the hazards identified and the operating practices required to manage them. Training can address combustible dust fundamentals, ignition prevention, housekeeping, equipment operation, maintenance, emergency procedures, and the safe operation of dust collection systems where applicable.
Sigma-HSE offers customized training following all applicable NFPA guidelines regarding combustible dust hazards. Our training helps your team identify and manage combustible dust risks, answers common questions about hazards and operating expectations, and supports your efforts to prevent fire and explosion incidents in your facility.
Why Engage Sigma-HSE?
Sigma-HSE combines process safety consulting with accredited combustible dust laboratory testing, allowing facilities to connect material characterization directly with their DHA. Our laboratory capabilities include Go/No-Go screening, Kst, Pmax, MIE, MEC, MIT, LOC, and other testing used to characterize combustible dust hazards.
Sigma-HSE supports a wide range of industries, including paper processing, with laboratory characterization, dust hazard analysis, combustible dust management, and employee training aimed at keeping facilities safe from combustible dust explosions and related hazards.
Contact our technical team to discuss your project.
Email: [email protected]
Phone: +1 (978) 880-5076
