NFPA 660 requirements: a sourced facility checklist

A facility cannot answer the NFPA 660 applicability question from a product name alone. Record where particulate is generated or received, the particle form, moisture and composition, normal and upset conditions, supplier information, and representative test evidence. OSHA's combustible-dust guidance identifies Kst, MIE, MEC, and particle size among relevant characteristics when known.

The purpose of the screen is to identify what is verified, what has been ruled out by valid evidence, and what still needs testing or professional evaluation. Never copy a Kst or ignition value from a similar material and present it as a facility fact.

NFPA's consolidation project moved content from NFPA 652, 61, 654, 655, 484, and 664 into NFPA 660. Old document numbers still appear in equipment specifications and historical reports, so retain them as traceability references. For current work, record the NFPA 660 edition and the applicable common and material- or industry-specific scope.

A simple legacy crosswalk is not a compliance determination. Facilities can handle several materials, and connected systems can cross boundaries. Have the reviewer explain which current sections govern each area and why.

A DHA should define the rooms, processes, equipment, material states, operating modes, and scenarios reviewed. It should identify ignition and consequence pathways, evaluate existing safeguards, state assumptions, and issue recommendations with enough context to close them correctly. Missing drawings or test data belong in the report as gaps, not silent assumptions.

Compare proposals by technical scope: process units, collection systems, sampling, fieldwork, scenario method, report depth, review cycle, exclusions, and professional responsibility. A low total with an undefined scope is not a reliable cost comparison.

The useful life of a DHA depends on what happens after issue. Assign each recommendation, document the selected safeguard or reason for another disposition, verify installation and operating information, and keep closure evidence. Screen material, equipment, throughput, layout, procedure, and safeguard changes against the DHA assumptions.

Periodic revalidation is a checkpoint, not a safe harbor between reviews. Incidents, near misses, inspections, supplier changes, and new test results can trigger an earlier look. Keep the standard edition, source links, dates, and decision owners with the record.

Begin with the material as it exists at each point in the process, not with a broad commodity label. OSHA's public guidance describes combustible dust in terms of a solid particulate that can present a fire or deflagration hazard when suspended in an oxidizing medium. It also explains that particle size, moisture, shape, composition, concentration, and other conditions can affect behavior. That makes a supplier name or a visual judgment an incomplete screen.

Create an applicability register for incoming material, intermediates, fines, recycled material, collected dust, and foreseeable upset conditions. For each entry, record the evidence available, its date, the sample or process state it represents, and the unresolved question. A qualified reviewer can then decide what may be supported by existing evidence and what needs representative testing. The register is an evidence map, not a material-property database or a compliance verdict.

A defensible scope identifies the physical and process boundaries a reader can verify. Name buildings, rooms, production lines, transfers, enclosures, storage, dust collectors, ducts, air-material separators, and interfaces with utilities or other processes. Identify normal production, startup, shutdown, cleaning, maintenance, changeover, and credible upset modes. If an area is excluded, state the exclusion and the reason.

This discipline prevents a facility-wide report title from masking an equipment-only review. It also supports later change screening: an owner can compare a proposed modification with the exact process state and boundary that were analyzed. Connected equipment deserves particular attention because a local event can interact with another area. DustDHA cannot decide those boundaries from a form; its intake simply helps the facility describe them consistently to prospective providers.

The input package should make current facts easy to distinguish from assumptions. Typical categories include process narratives, material flow, current layouts, equipment and collector information, control descriptions, electrical-area records, ventilation information, representative test reports, safety data, operating and cleaning procedures, prior DHAs, open recommendations, incidents, near misses, inspections, and management-of-change records. Revision dates and owners matter because an undated drawing can look authoritative while describing retired equipment.

Ask the provider to return an input register that marks each item accepted, superseded, missing, or requiring verification. Missing evidence is not automatically a project failure; hiding the gap is. The report should say how each gap affected scope, assumptions, recommendations, or follow-up. That record gives future reviewers a rational starting point and avoids turning undocumented memory into a facility fact.

Each analyzed scenario should be traceable to the relevant material and operating condition, credible ignition and propagation path, affected equipment or area, existing safeguards, and resulting action or documented conclusion. The level of detail should let another qualified reviewer understand what was considered without reconstructing the project from meeting notes. A generic checklist can support field collection, but it should not replace scenario reasoning.

Recommendations need enough context for an owner to implement and close them correctly. Record the issue addressed, responsible owner, selected action, dependencies, due date, technical acceptance evidence, and disposition. If the facility chooses another safeguard or rejects a recommendation, preserve the technical basis and authorization. Traceability turns the DHA from a static report into a managed safety record while keeping engineering responsibility with the facility and its qualified advisers.

A change screen should compare the proposal with the material, process, equipment, throughput, control, building, and operating assumptions recorded in the analysis. Supplier substitutions, finer fractions, recycled content, increased speed, altered ventilation, collector changes, duct rerouting, enclosure changes, software or interlock changes, and revised cleaning methods can all matter. The screen should identify who reviewed the comparison and whether the DHA, a drawing, a procedure, testing, or training requires revision.

Do not wait for a calendar reminder when a change invalidates a key assumption. Conversely, do not label every maintenance activity a full DHA revalidation without examining what changed. A documented screen creates the middle path: it shows why an existing analysis remains representative or why focused or broader review is needed. This page provides a workflow for that record, not the technical acceptance decision.

The analysis and daily controls should describe the same facility. Compare the report's assumed housekeeping, inspection, preventive maintenance, hot-work control, ignition-source control, impairment handling, emergency response, and training practices with current procedures and field conditions. If a safeguard depends on an inspection or action, the owner, frequency, acceptance criteria, and record should be identifiable.

This comparison is also useful during procurement. Ask whether a provider's scope includes interviews, field verification, procedure review, and discussion of how recommendations enter the management system. A report can identify hardware and operational needs without the consultant operating the program. The facility remains responsible for implementing and maintaining controls; a qualified provider should make assumptions and interfaces visible enough for that work to continue after the report is delivered.

Keep technical applicability separate from the route by which a requirement may affect the site. The record can identify the current NFPA edition used, an adopted fire or building code, authority-having-jurisdiction direction, permits, insurer conditions, customer or contract requirements, and the relevant OSHA or State Plan context. OSHA's revised combustible-dust National Emphasis Program is an inspection directive; it is not a substitute for reading the regulations and other authorities applicable to a facility.

Record the source URL, publication or effective date where known, date checked, jurisdiction, and person responsible for confirming it. Avoid an unsupported national slogan such as one universal enforcement date. Local adoption and site obligations can differ. Technical and legal advisers can evaluate the actual path; DustDHA's state and deadline surfaces deliberately stop short of declaring it.

A short readiness review should produce a scope list, material and evidence register, current document index, prior-analysis status, known changes, open findings, requested deliverables, site-access constraints, and named decision team. Separate facts from questions. Identify which records can be shared during proposal, which require a confidentiality agreement, and which must be collected after award.

Send equivalent information to each bidder and give them the same opportunity to ask questions. Request a written scope matrix covering included areas, field time, workshops, tests, calculations, draft review, report format, recommendations, exclusions, schedule, travel, and technical responsibility. This does not choose the engineer for you. It makes proposal differences visible and gives the selected team a cleaner project start.