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Dust Hazard Analysis (DHA)

A Dust Hazard Analysis is the foundation for combustible dust compliance and engineered protection decisions, venting, suppression, isolation, and ignition control all start here.

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What a DHA is | Requirements and standards | SSI DHA process | Dust testing and data | Design considerations | What you receive | Service area | FAQs | Resources

What is a Dust Hazard Analysis?

A Dust Hazard Analysis (DHA) is a structured review of your processes, equipment, building features, and operating practices to identify combustible dust fire and explosion hazards, then determine what safeguards are needed to reduce risk to an acceptable level.

The key word is specific, a defensible DHA maps hazards to real equipment nodes, evaluates credible ignition sources, considers propagation paths, and verifies whether existing safeguards are adequate.

Why DHAs matter in the real world

• Secondary explosions can be larger than the first event when layered dust is dispersed into a cloud
• Propagation can occur through ducting, conveyors, and interconnected vessels without isolation
• Assumptions fail when material changes, moisture changes, particle size shifts, or process conditions drift
• Audits and enforcement typically focus on documentation, housekeeping, ignition controls, and whether safeguards match the hazards

Requirements and Standards

Most combustible dust programs anchor to NFPA requirements and OSHA enforcement priorities. Your AHJ, insurer, and corporate standards may add additional expectations.

When a DHA needs review or update

Many facilities treat DHAs like a one time event. That is a mistake. A DHA should be reviewed on a defined cadence and whenever conditions change.

Trigger	Why it matters
Process or equipment changes (MOC)	New ignition sources, new dust generation points, or new propagation pathways
Material changes, new products, new suppliers	Dust behavior can shift with particle size, moisture, additives, and blends
Building, ventilation, or collector modifications	Venting discharge, indoor hazards, and confinement conditions can change
Fire, deflagration, near miss, or recurring hot work	Your credible scenarios just became more credible
Audit findings, insurer requests, or AHJ questions	Documentation and safeguard adequacy are under scrutiny

SSI’s Dust Hazard Analysis Process

SSI follows a practical, code-aware approach that connects documentation to real decisions. If you need a DHA that actually helps you choose safeguards, sequence upgrades, and defend decisions, this is the difference.

Phase 1, scope and site evaluation

• Confirm processes, materials, and equipment nodes where dust is generated, conveyed, collected, or stored
• Review drawings, flow paths, ventilation, housekeeping practices, and operating procedures
• Identify credible ignition sources, mechanical, electrical, thermal, static, and hot work related

Phase 2, dust data and explosibility inputs

If you do not have defensible data, you are guessing. SSI can coordinate combustible dust testing and help you connect results to design decisions.

Phase 3, hazard identification and risk evaluation

• Where can hazardous dust layers accumulate, where can hazardous clouds form
• What ignition sources are credible, how likely are they, and what prevents them
• How could flame and pressure propagate through connected systems
• Are existing safeguards appropriate, maintained, and documented

Phase 4, recommendations and a practical path forward

The output should not be a list of generic statements. It should tell you what to do, where, and why, in a way that supports both compliance and budget planning.

• Prioritized recommendations, focused first on credible high consequence scenarios
• A clear link between hazards and safeguards, including what standard or expectation drives the need
• Implementation planning support, including service and lifecycle considerations

Dust Testing and Characterization

Many facilities assume their dust is low risk because the product does not seem flammable. Dust changes the physics. Even materials that do not burn in larger form may be explosible when finely divided and dispersed, testing removes the guesswork.

Design Considerations After a DHA

A DHA often points to layered safeguards, not a single fix. The right mix depends on the dust, the equipment, occupancy, and whether venting to a safe location is possible.

What You Receive From SSI

Your DHA deliverable should be usable. SSI focuses on producing documentation that supports decisions, implementation, and long term compliance, not just a report that sits on a shelf.

• A documented inventory of relevant equipment nodes and dust hazard locations
• Credible ignition source evaluation and existing safeguard review
• Prioritized recommendations, engineering controls and administrative controls
• Clear next step options, from testing to engineered protection selection
• Support for implementation planning, through SSI sales, installation, and service teams when needed

Common next steps after a DHA

• Complete or update dust testing to remove unknowns
• Select explosion protection for dust collectors, silos, and connected ducting
• Implement isolation to prevent propagation into buildings and adjacent equipment
• Improve ignition source controls and housekeeping, then document the program

Service Area

SSI is headquartered in Breinigsville, Pennsylvania and supports combustible dust facilities across the Mid-Atlantic and Northeast, including many sites within a practical 12-hour drive for on-site evaluation, implementation, and ongoing service. For background on SSI, see About SSI.

Dust Hazard Analysis FAQs

Is a DHA required if we only have nuisance dust?

Maybe. The key question is whether the dust is combustible and whether it can accumulate or form a cloud under credible operating conditions. If you are unsure, start with dust characterization and testing.

Does OSHA require a DHA?

OSHA commonly references combustible dust hazards through enforcement directives and inspection focus areas. Many facilities align their combustible dust programs to NFPA requirements and use a DHA as the core documented hazard evaluation. See: OSHA combustible dust enforcement.

What is the role of dust testing in a DHA?

Testing provides defensible inputs for severity and ignition sensitivity. It helps engineering teams select safeguards based on real dust behavior instead of assumptions. Start here: Combustible Dust Testing.

What equipment is usually included in a DHA?

Any equipment where dust is generated, conveyed, collected, or stored may be included, collectors, ducts, cyclones, filters, silos, mixers, grinders, dryers, packaging, transfer points, and hidden accumulation zones above ceilings and on structural members.

Resources, Downloads, and References

Related SSI Pages

• Explosion Venting
• Explosion Venting vs Suppression, how to choose
• Explosion Suppression Systems
• Explosion Isolation
• Spark Detection Systems
• Fire and Explosion Protection FAQs