For years, combustible dust compliance forced facility managers, engineers, and safety teams to navigate a maze of overlapping NFPA standards. You had the “fundamentals” in NFPA 652, then separate commodity standards like NFPA 61 (agricultural dust), NFPA 484 (metal dust), NFPA 654 (general dusts), NFPA 655 (sulfur), and NFPA 664 (wood).
The result? Conflicting interpretations, inconsistent enforcement, and plenty of confusion between designers, system owners, and Authorities Having Jurisdiction (AHJs).
Effective December 6, 2024, NFPA 660: Standard for Combustible Dusts and Particulate Solids replaces the major dust-related NFPA standards with one consolidated document. Its purpose is straightforward: provide a single, unified framework that clarifies requirements, removes contradictions, and gives organizations a clearer path to compliance.
While the document number and structure are new, the core safety principles remain firmly in place. NFPA 660 reinforces, and in some areas strengthens, the practices already familiar to dust-producing operations:
660 retains the requirement for an initial DHA and continues the 5-year revalidation cycle. Facilities must identify where dust is generated, how it accumulates, and how ignition sources are controlled.
Static electricity remains one of the most common ignition sources. Conductive ducting and verified electrical continuity are still critical for safe system design.
660 stresses controlling fugitive dust layers and ensuring equipment can be opened, inspected, and cleaned. Ducting that disassembles quickly, such as Nordfab Quick-Fit®, makes these tasks easier, which helps facilities maintain compliance and reduce downtime.
NFPA 660 simplifies the rulebook but doesn’t change the physics. Safe airflow, clean systems, and effective ignition control are still the backbone of compliance. The new standard simply makes it clearer—and easier—to get there.