Combustible Dust Explosions

Per OSHA, combustible dusts are fine particles that present an explosion hazard when suspended in air in certain conditions. A dust explosion can be catastrophic and cause employee deaths, injuries, and destruction of entire buildings. In many combustible dust incidents, employers and employees were unaware that a hazard even existed.

Industries at Risk

Combustible dust explosion hazards exist in a variety of industries, including agriculture, chemicals, fertilizer, plastics, wood, forest, paper, pulp, rubber, pesticides, pharmaceuticals, tire and rubber manufacturing, dyes, coal, metal processing (e.g., aluminum, chromium, iron, magnesium, and zinc), fossil fuel power generation (coal), and additive manufacturing and 3D printing. Many of these industries are represented on the UND campus.

By understanding the ignition risks, facilities can implement effective safety measures such as dust control, proper ventilation, ignition source management, and explosion protection systems.

Dust Control Recommendations

• Implement good housekeeping;
• Use proper dust collection systems and filters;
• Minimize the escape of dust from process equipment or ventilation systems;
• Use surfaces that minimize dust accumulation and facilitate cleaning;
• Inspect for dust residues in open and hidden areas at regular intervals;
• If ignition sources are present, use cleaning methods that do not generate dust clouds;
• Use only vacuum cleaners approved for dust collection; and
• Locate relief valves away from dust deposits.

Ignition Control Recommendations

• Ensure electrical equipment and wiring are in good repair;
• Control static electricity, including bonding of equipment to ground;
• Control sources of heat, open flames, and sparks;
• Control mechanical sparks and friction;
• Use separator devices to remove foreign materials capable of igniting combustibles from process materials;
• Separate heated surfaces from dusts;
• Separate heating systems from dusts;

Injury and Damage Control Methods

• Separation of the hazard (isolate with distance or barrier);
• Pressure relief venting for equipment;
• Direct vents away from work areas;
• Specialized fire suppression systems;
• Explosion protection systems;
• Spark/ember detection for suppression activation;
• Develop an emergency action plan; and
• Maintain emergency exit routes.

OSHA FactSheet on Combustible Dust Explosions