Getting Control of Combustible Dust

OSHA's planned combustible dust standard isn't dead; the agency's Spring 2015 regulatory agenda still listed it as being in the "prerule stage" but indicated OSHA intends to have a small business panel consider it beginning in February 2016. The U.S. Chemical Safety Board still lists a completed OSHA standard as one of its Most Wanted Safety Improvements.

Many employers are confused about what kinds of dust are combustible and how to address combustible dust issues. Fortunately, two experts from Nilfisk-Advance Inc.'s Industrial Vacuum Division, Product Manager Dan Peterson and District Sales Manager Gerard Geiger, presented an OH&S webinar in October 2014 that clarified some misconceptions and explained how to comply with key codes and standards, such as NFPA 654 and the National Electric Code.

Combustible dust incidents have affected many industries, including agriculture, chemicals, food processing, grain, plastics, rubber, coal, and metals, Geiger pointed out. "Housekeeping has not been adequate in many cases," he explained. Geiger discussed the dust explosion pentagon—oxygen, heat, dispersion, fuel, and confinement—adding that the goal of control strategies is to eliminate one of these. Employers with combustible dusts should start by identifying all spaces where dust can accumulate and all ignition sources, he said.

Although OSHA has not promulgated its standard, the agency did launch a National Emphasis Program in March 2008. Its compliance directive listed 15 industries that OSHA indicated have more frequent or high-consequence combustible dust fires and explosions, as well as 49 other industries that have the potential for combustible dust fires and explosions.

Both Geiger and Peterson stressed that vacuuming is the preferred method of cleaning combustible dusts, according to the NFPA 654 standard. Employers should only use vacuums that are approved for dust collection and should keep dust residues to less than 1/32 inch thick, they explained. Peterson cleared up several myths in his part of the webinar:

  • There is no such thing as an NFPA-approved vacuum.
  • You can still have combustible dust in a non-classified (non-hazardous) facility.
  • Vacuums must meet certain requirements to be called "explosion proof."
  • Pneumatic equipment cannot be certified "explosion proof."

Both NFPA 654 and the National Electric Code require that vacuums be NRTL-approved for use in classified (hazardous) environments, Peterson said.

Posted by Jerry Laws on Jun 17, 2015