Combustible Dusts


Combustible dusts are finely-ground organic or metal particles found in a variety of industries and workplaces. Potentially dangerous accumulations of combustible dust can build up inside process equipment or escape from process equipment and settle on surfaces in the general work area. These accumulations are extremely explosive when dispersed into the air in the presence of commonplace ignition sources, such as standard electrical switches.

Dust explosions can be catastrophic and cause death, injury, and destruction of entire buildings. In many combustible dust accidents, employers and employees were unaware that a hazard existed.

Fortunately, you can take steps to protect employees and others from this possible danger. This page provides a variety of information that can help you learn more about the risk for combustible dust hazards in your workplace and what you can do to keep individuals safe.


Workplace safety and health rules that address combustible dust hazards have been established to prevent hazardous dust accumulations, control possible ignition sources, and minimize the danger to individuals and damage in an explosion.

This page lists safety & health rules that apply to combustible dust hazards in Washington State.


WRD 12.85 Enforcement and Consultation Guidance for Combustible Dust Hazards, December 30, 2008. (142 KB PDF)

WRD 89-3b Grain Handling Facilities-Inspection Guidance and Standards Clarification, September 1, 1994. (37 KB PDF)


The following resources are available to inform you about the hazards of combustible dusts and what you can do to keep workplaces safe from combustible dust hazards:


Videos under the subject of "Combustible Dust" can be found here.

Video from CSB Video Archives (Take More Action to Prevent Dust Explosions, 2-4-2009)

Video from CSB Video Archives (Combustible Dust: An Insidious Hazard, 7-28-09)

Video from CSB Video Archives (Iron In The Fire, 1-5-2012)

Consultation Assistance

L & I provides consultations, training, and technical assistance at no cost to employers. If you would like help with identifying and addressing combustible dust hazards please visit



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