Any combustible material (and some materials normally considered noncombustible) can burn rapidly when in a finely divided form. If such a dust is suspended in air in the right concentration, it can become explosive. The force from such an explosion can cause employee deaths, injuries, and destruction of entire buildings. Such incidents have killed scores of employees and injured hundreds over the past few decades.
Materials that may form combustible dust include metals (such as aluminum and magnesium), wood, coal, plastics, biosolids, sugar, paper, soap, dried blood, and certain textiles. In many accidents, employers and employees were unaware that a hazard even existed.
A combustible dust explosion hazard may exist in a variety of industries, including: food (e.g., candy, sugar, spice, starch, flour, feed), grain, tobacco, plastics, wood, paper, pulp, rubber, furniture, textiles, pesticides, pharmaceuticals, dyes, coal, metals (e.g., aluminum, chromium, iron, magnesium, and zinc), and fossil fuel power generation.
This page highlights OSHA standards, directives (instructions for compliance officers), and national consensus standards related to combustible dust.
Section 5(a)(1) of the OSH Act, often referred to as the General Duty Clause, requires employers to “furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees”. Section 5(a)(2) requires employers to “comply with occupational safety and health standards promulgated under this Act”.
Note: Twenty-five states, Puerto Rico and the Virgin Islands have OSHA-approved State Plans and have adopted their own standards and enforcement policies. For the most part, these States adopt standards that are identical to Federal OSHA. However, some States have adopted different standards applicable to this topic or may have different enforcement policies.
General Industry (29 CFR 1910)
- 1910 Subpart D, Walking-working surfaces [related topic page]
- 1910.22, Housekeeping
- 1910 Subpart E, Exit routes, emergency action plans, and fire prevention plans
- 1910.38, Emergency action plans
- 1910 Subpart G, Occupational healthand environmental control
- 1910 Subpart J, General environmental controls
- 1910 Subpart L, Fire protection
- 1910 Subpart N, Materials handlingand storage
- 1910 Subpart R, Special industries
- 1910 Subpart S, Electrical [related topic page]
- 1910.307, Hazardous (classified) locations
- 1910 Subpart Z, Toxic and hazardous substances [related topic page]
- Combustible Dust National Emphasis Program. OSHA Directive CPL 03-00-008, (2008, March 11).
- Search all available directives.
Note: These are NOT OSHA regulations. However, they do provide guidance from their originating organizations related to worker protection.
- Codes and Standards. National Fire Prevention Association (NFPA) develops, publishes, and disseminates more than 300 consensus codes and standards intended to minimize the possibility and effects of fire and other risks. Virtually every building, process, service, design, and installation in society today is affected by NFPA documents.
- 61, Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities
- 484, Standard for Combustible Metals
- 654, Standard for the Prevention of Fires and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids
- 655, Standard for Prevention of Sulfur Fires and Explosions
- 664, Standard for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities
Consensus Standards and the General Duty Clause
Using Consensus standards to support a 5(a)(1) Citation:
A consensus standard can be used to show “industry recognition” of a hazard. However, the hazard must be recognized in the employers’ industry, not an industry other than the employers’ industry.
- is not used to enforce “should” standards.
- is not used to required abatement methods not required by a specific standard.
- is not normally used to cover categories of hazards exempted by an OSHA standard.
- Each employer shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employee;
- The general duty provisions can only be used where there is no standard that applies to the particular hazard involved.
Evaluation of Potential 5(a)(1) situations:
- Employer failed to keep workplace free of hazards to which employees of that employer were exposed.
- Must involve a serious hazard and employee exposure
- Does not specify a particular abatement method – only that the employer keeps the workplace free of serious hazards by any feasible and effective means.
- The hazard must be reasonably foreseeable.
- The hazard was recognized.
- Industry recognition
- Employer recognition
- Common-sense recognition
- The hazard caused or was likely to cause death or serious physical harm.
- Feasible means to correct the hazard were available.
Other Investigations (CSB)
Dust from industrial processes can become the fuel for devastating explosions.
Imperial Sugar Company Dust Explosion and Fire
Combustible Dust Hazard Investigation
Hayes Lemmerz Dust Explosions and Fire
CTA Acoustics Dust Explosion and Fire
West Pharmaceutical Services Dust Explosion and Fire