How to Complete a Dust Hazard Analysis Template

A dust hazard analysis template is the structured document a facility uses to identify where combustible dust accumulates, judge how bad a fire or explosion could be, and record the safeguards already in place or still needed. The most widely used format sits in Annex B of NFPA 652, which requires every facility handling combustible dust to complete an analysis.¹ The template only works if the data behind it is real, so most of the work happens before you type anything into the fields.

Data to Gather Before You Open the Template

Material Properties

Every DHA template asks for the explosive characteristics of the dusts your facility handles. The two numbers that matter most are Kst, which measures how fast a dust explosion’s pressure rises, and Pmax, which measures the peak pressure the explosion can generate. A testing lab produces these figures under ASTM E1226 by igniting a dust sample in a sealed chamber and recording pressure behavior.

Start by pulling the Safety Data Sheet for every material you process, store, or transport. SDSs list chemical composition and general flammability, but they rarely include Kst or Pmax. That gap is the reason lab testing matters. A Kst of zero means the dust is not explosible and the analysis for that material simplifies. Any Kst above zero means the dust can explode, and OSHA can issue a General Duty Clause citation for uncontrolled hazards involving that material.²

Equipment and Ignition Source Controls

The template needs a complete list of every piece of process equipment that contacts or generates combustible dust: collectors, conveyors, mixers, grinders, dryers, silos, and bucket elevators. For each item, record its specifications, its location, and the ignition source controls in place. Grounding and bonding against static discharge are the most common. Spark detection systems, magnetic separators, and explosion venting or suppression hardware round out the list.

Electrical equipment in areas where combustible dust may be present needs a hazardous location classification. Federal regulations require that equipment be approved for the specific class and group of dust present and marked with its operating temperature range.³ For combustible dust that generally means Class II, Division 1 where dust is normally present in ignitable concentrations, or Division 2 where dust is present only under abnormal conditions. Recording these classifications in the template documents that the electrical equipment matches the hazard level in each area.

Accumulation Measurements

Walk the facility with a ruler. Under NFPA 654, a dust layer deeper than 1/32 of an inch covering more than 5 percent of the floor area, or more than 1,000 square feet, whichever is less, triggers a hazard finding. Layers at or below 1/64 of an inch are negligible. NFPA 664 sets the wood processing threshold at 1/8 of an inch. NFPA 484 for combustible metals uses a simpler test: if the layer obscures the color of the surface underneath, it’s too much. Measuring and recording depths zone by zone gives the analysis real teeth instead of vague statements about housekeeping.

Where to Get the Template

The reference format is Annex B of NFPA 652, labeled “Dust Hazards Analysis — Example.”¹ It provides structured tables covering hazard identification, existing safeguards, risk ratings, and corrective actions. NFPA sells the standard through its website; the print edition runs roughly 96 pages.

OSHA’s Combustible Dust National Emphasis Program directive (CPL 03-00-008) is worth reading alongside the template. It does not contain a fill-in form, but it lays out how inspectors evaluate combustible dust hazards and what evidence they look for, which tells you which fields will get the closest scrutiny.² Older versions of the directive included checklist appendices; those have been moved to the OSHA Technical Manual chapter on combustible dusts.

Industry groups such as the American Institute of Chemical Engineers publish sector-specific DHA guidance. Treat the NFPA annex as the baseline and layer industry material on top.

Filling In the Template

Divide the Facility Into Zones

Break the facility into distinct functional areas. The common split separates process areas, where raw materials are converted or modified, from material handling zones, where dust is transported, stored, or packaged. Give each zone a unique identifier, such as MH-01 for the first material handling area, so you can track hazards across a large floor plan without confusion. Every room, corridor, and outdoor area where dust could reasonably accumulate needs its own entry. Skipping a zone because it looks clean today creates a blind spot.

Enter Hazards and Safeguards Side by Side

For each zone, walk the equipment list and document every scenario where a combustible dust cloud could form. A hopper being loaded, a conveyor transfer point, a bag dump station: each gets its own row. Next to each hazard, record the safeguards in place: explosion venting, chemical suppression, deflagration isolation valves, or a housekeeping schedule. The value of the template is the side-by-side comparison, which makes gaps visible.

Enter the Kst and Pmax values for the specific dust present in each zone. Those numbers justify the risk rating. A zone handling dust with a Kst above 200 bar·m/s, classified as St 2 or “strong,” demands more robust safeguards than a zone with a Kst barely above zero. If the existing protections don’t match the severity of the dust, the corrective actions column is where that mismatch gets flagged.

Rate Risk and Assign Corrective Actions

Most DHA templates use a risk matrix that combines the likelihood of a dust event with the severity of its consequences. Rate each hazard entry on both scales, and the intersection produces a risk level, typically low, moderate, high, or critical. High and critical risks need corrective actions with deadlines. The template provides space for what needs to change, who is responsible, and when it should be complete. This section becomes the facility’s roadmap for safety spending, so write it in usable terms. “Improve housekeeping” gives no one a task. “Install automated dust collection at transfer point CV-03 by Q3 2026” does.

Who Should Lead and Staff the Analysis

NFPA 652 requires the DHA to be performed or led by a “qualified person,” but the standard doesn’t pin that to a specific degree or certification. Annex A describes the qualified person as someone familiar with conducting DHAs and knowledgeable about combustible dust hazards. In practice, that can be a facility engineer, a process safety consultant, an equipment manufacturer’s representative, or a plant operator with deep experience in the process.

What matters more than the lead person’s title is the combined expertise of the team. Annex A suggests the team should collectively cover familiarity with the process, operations and maintenance knowledge, understanding of safety systems and equipment, material properties expertise, the facility’s operating history, and emergency procedures. Analyses done by a single person working alone tend to have gaps, especially when that person doesn’t know the day-to-day process. The U.S. Chemical Safety Board has noted that a limited pool of qualified DHA practitioners, and the tendency to treat the completed document as an endpoint rather than a living tool, are recurring weaknesses across industries.⁴

Which Standard Governs Your Dust

NFPA 652 is the umbrella, but it defers to commodity-specific standards where they exist: NFPA 61 for agricultural and food processing, NFPA 484 for combustible metals, NFPA 654 for general combustible particulate solids, NFPA 655 for sulfur, and NFPA 664 for wood processing and woodworking.¹ Where a commodity standard sets a different requirement from NFPA 652, follow the commodity standard. Where the commodity standard is silent, NFPA 652 fills the gap.

This matters for the template because accumulation thresholds, testing requirements, and safeguard specifications shift with the standard. A wood products plant under NFPA 664 works to a 1/8-inch accumulation threshold; a facility handling metal powders under NFPA 484 flags any visible layer. Reference the specific standard that governs your materials rather than defaulting to NFPA 652 for everything.

Common Mistakes That Weaken the Finished Document

The most damaging mistake is treating the DHA as a one-time compliance checkbox. The Chemical Safety Board’s review found that most facilities view a completed hazard analysis as the end goal, with nothing happening afterward to act on findings or keep the document current.⁴ A DHA that sits in a binder creates a false sense of security.

Other failures that show up repeatedly:

Skipping dust testing and assuming Kst and Pmax from the SDS. SDSs rarely include those figures, and guessing wrong makes every risk rating in the template unreliable.
Incomplete zone coverage. Overhead surfaces, ductwork interiors, and areas behind equipment are easy to miss and are exactly where dangerous accumulations hide.
Vague corrective actions. Entries like “address housekeeping issues” give no one a clear task, timeline, or budget. Inspectors and insurers read this column closely.
Softened findings. Some facilities downplay hazards because they worry the DHA will be used against them in litigation or enforcement. That defeats the point of the analysis.
Solo authorship without process knowledge. An outside consultant who never speaks to operators or maintenance staff produces a document that looks polished but misses facility-specific risks.

Keeping the Template Current

NFPA 652 requires DHAs to be reviewed and updated at least every five years. If the facility changes its production process, introduces a new material, or modifies equipment in a way that affects dust generation or containment, the update happens then, not at the next five-year mark. The five-year cycle is a ceiling. Facilities that wait until the deadline often find the document no longer reflects their actual operations, which means they’ve been running without a valid safety analysis for however long the changes have been in place.

Keep the completed DHA where safety inspectors, facility leadership, and emergency responders can reach it quickly, with a digital copy backed up offsite. OSHA’s General Duty Clause requires employers to maintain a workplace free of recognized serious hazards, and having the DHA available demonstrates that combustible dust risks have been identified and addressed.² The document also supports employee safety training and emergency drills.

There is no standalone OSHA combustible dust standard. Enforcement comes primarily through the General Duty Clause and existing standards for electrical equipment, housekeeping, and hazard communication. When OSHA inspects under its Combustible Dust National Emphasis Program, inspectors use NFPA standards as evidence of industry-recognized hazards and feasible abatement.² A missing or outdated DHA makes it straightforward for an inspector to document that recognized hazards weren’t addressed, and a single inspection tends to generate multiple citations because the hazard touches electrical classification, housekeeping, hazard communication, and training at once.

1
National Fire Protection Association. NFPA 652 Standard on the Fundamentals of Combustible Dust
2
Occupational Safety and Health Administration. OSHA Instruction CPL 03-00-008 – Combustible Dust National Emphasis Program
3
Occupational Safety and Health Administration. 29 CFR 1926.407 – Hazardous (Classified) Locations
4
U.S. Chemical Safety Board. Dust Hazard Learning Review