OSHA is intensifying its efforts to address combustible dust fire and explosion hazards. Numerous dust fires and explosions have occurred in the last few years, including the highly publicized sugar dust fire and explosion at the Imperial Sugar Refinery near Savannah, Georgia on February 7, 2008 that killed 13 workers and injured more than 60 others. These events have pressured OSHA to take aggressive enforcement and outreach efforts to combat combustible dust hazards, including a new Combustible Dust National Emphasis Program. Congress is also getting involved. 

Combustible dust can exist in many materials and many industries.  Although hazardous combustible dusts are sometimes associated with grain dust in grain handling facilities or coal dust in electrical power plants, both of which are regulated by OSHA, combustible dust can also include metal dust (such as aluminum and magnesium), wood dust, plastic dust, organic dust (such as sugar, paper, soap), and dust from certain textiles. Some industries that handle combustible dust include agriculture, chemical, textile, forest and furniture products, wastewater treatment, metal processing, paper products, pharmaceuticals and recycling operations.

OSHA has very few standards, which directly regulate combustible dust.  Many local jurisdictions have enacted fire codes that address combustible dust fire and explosion hazards. The National Fire Protection Association (NFPA) has also adopted a number of consensus standards on the subject. To strengthen its enforcement, OSHA adopted a Combustible Dust National Emphasis Program in October 2007. The Program provides guidance to OSHA inspectors on how to inspect and issue citations for combustible dust

hazards. Here are the highlights:

• As with other National Emphasis Programs, such as excavations or amputation hazards, OSHA will now start to target facilities where employees may be exposed to combustible dust hazards. A list of targeted industries by SICS and NAICS Code is included in the Program.
•  In one of the more controversial aspects of the Program, OSHA inspectors are now directed to inspect and cite excessive levels of dust accumulation on floors, beams, ducts and other surfaces. "Excessive" is defined as a dust layer of 1/32 of an inch (approximately the thickness of a paper clip) or more on at least 5% of the floor and surface area up to 20,000 square feet. For rooms over 20,000 square feet, a dust layer of 1,000 square is the limit.  Many employers, including those with well-defined dust control and housekeeping practices, may have difficulty complying with this provision.
• OSHA inspectors are also directed to inspect dust collectors, duct work and other containers for possible combustible dust accumulation.  Inspectors will also evaluate employer's efforts to control dust accumulations, such as isolation of dust generating processes, elimination of ignition sources and appropriate electrical equipment. Employers will be cited if combustible dust hazards exist and prevention methods are inadequate.
• The Program provides very little guidance as to what constitutes acceptable combustible dust prevention methods, but instead refers employers to NFPA publications, especially NFPA 654, "Standard for the Prevention of Fires and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulates Solids."
• The Program lists the various OSHA standards under which employers can be cited for combustible dust hazards, including grainhandling, housekeeping, personal protective equipment (PPE), process safety management, electrical, welding, and fire protection, among others.  Where no specific standard applies, OSHA inspectors are directed to cite employers with General Duty Clause violations. The General Duty Clause of the OSHA Act requires all employers to provide a workplace free from recognized hazards likely to cause death or serious physical injury.  Given the absence of specific standards, we anticipate that many citations will be issued under the General Duty Clause with reliance on NFPA consensus standards to prove industry recognition of the hazard and feasible abatement methods.

Unconvinced that OSHA is moving fast enough to resolve the problem, the U. S. House of Representatives has proposed legislation that would force OSHA to issue new specific rules regulating combustible dust. The Combustible Dust Explosion and Fire Prevention Act (HR 5522) would require OSHA to issue an interim rule in 90 days and a final rule in 18 months.  The bill has passed a voice vote by the House Education and Labor Committee.  OSHA and some industry groups oppose the bill, and in particular its tight deadlines for passage of a complicated new rule, arguing instead that OSHA's National Emphasis Program should be given a chance to work. Final passage of the bill by Congress before the end of the year is uncertain.

Employers with potential combustible dust hazards should know that OSHA will now be targeting and inspecting their facilities under the National Emphasis Program. Those employers should familiarize themselves with the Program and, as appropriate, take steps to evaluate and address combustible dust hazards in their facilities. The combustibility of dust can be a complex issue, requiring expert assistance. 

OSHA's Combustible Dust National Emphasis Program, CPL 03-00-06, and other materials on combustible dust can be found at OSHA's website, www.osha.gov by searching under "Combustible Dust".