Dust is defined as solid particles that are generated by some type of mechanical action on organic or inorganic materials. These mechanical actions include, but are not limited to, handling, crushing and grinding. Dust particles that are too large to remain airborne will settle out, while the smallest ones can remain suspended indefinitely.
In general terms, a combustible dust is a combustible solid particle having an effective diameter of 420 microns (μm) or smaller and is capable of being suspended in air.
What are the hazards associated with combustible dust?
Combustible dusts when suspended in air in sufficient concentration can result in a fire or explosion when ignited by an ignition source, such as a flame or electric arc, resulting in extensive property damage and serious human injury and death.
What can I do to protect myself?
Your employer is required to conduct a workplace hazard assessment, a part of which should include the identification of processes and materials that are capable of producing combustible dust. In addition, the employer is also responsible to inform employees about the physical hazards, as well as the health hazards, associated with any materials used in the workplace.
What resources are available to assist employers?
Safety and Health Programs
Several example checklists and programs pertaining to combustible dust can be downloaded and customized to fit the workplace. They include the self-inspection checklist, hazard communication program, PPE hazard assessment, respiratory protection program, and confined space entry program.
Training and Outreach Services
In addition, the education, training and technical assistance bureau provides free online safety and health training and outreach services (i.e., speaker's bureau requests, safety booths) upon request.
Lastly, the NCDOL Library offers free safety and health videos (including streaming video services) and related research assistance on consensus standards (i.e., ANSI, NFPA, NEC).
A-Z Safety and Health Topics
The consultative services bureau provides free and confidential onsite consultation regarding worksite safety and health hazards.
What regulations apply?
OSH has adopted the following standards that are applicable to combustible dusts. Note: Please also check the standards information and activity webpage to see if there has been any recent or upcoming regulatory activity on this topic.
29 CFR 1910.22 - housekeeping
29 CFR 1910.94 - ventilation
29 CFR 1910.146 - permit-required confined spaces
29 CFR 1910.176 - handling materials - general
29 CFR 1910.261 - pulp, paper, and paperboard mills
29 CFR 1910.263 - bakery equipment
29 CFR 1910.265, - sawmills
29 CFR 1910.272 - grain handling facilities
29 CFR 1910.307 - hazardous (classified) locations
29 CFR 1910.1200 - hazard communication
General Duty Clause
The General Duty Clause located in N.C.G.S. 95-129(1) can be invoked for the protection of employees against recognized serious hazards such as combustible dusts for which no OSH standard exists.
Other Applicable Standards
The Which OSHA Standards Apply webpage can help identify other standards that may be applicable to your worksite.
Where can I learn more?
- Industry Guide 49 - OSHA General Industry Standards Requiring Programs, Inspections, Procedures, Records and/or Training provides requirements for standards related to combustible dusts in general industry.
- Compliance Directive: CPL 03-00-008 establishes enforcement policy regarding combustible dust and identifies applicable standards and laws and an explanation of the application of these to ensure uniform enforcement.
If you would like to receive interpretive guidance on this or any other OSH standard or topic, you can submit your questions using the Ask OSH web form, by e-mail to firstname.lastname@example.org or by calling 919-707-7876.