To Avoid OSHA Citation, Firms Must Deal with Dust

Dust may seem innocuous, but it can cast an expensive cloud on manufacturing facilities.

The accumulation of suspended, combustible sugar dust can spark an explosion, as it did in February 2008 at the Imperial Sugar Company in Port Wentworth, Ga., killing 13 people, injuring 40 others and causing a series of secondary explosions that spread through adjacent buildings.

Still, many composites industry professionals—even ones well trained in the safety routines of their facilities—are unaware of the hazards of dust, said Perry Bennett, Health, Safety and Environmental director at Molded Fiber Glass Companies. He spoke to COMPOSITES 2010 attendees about mitigating and controlling combustible dusts in FRP processes.

Bennett warned attendees that regulatory agencies are getting more serious about the topic. The Occupational Safety and Health Administration (OSHA) will soon release changes to its principal dust document, “NFPA 654, Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids,” and Bennett recommended that composites professionals realize they can be cited for noncompliance with NFPA 654.

Part of the problem with regulating dust explosions is the confusion about which dusts can explode and under what conditions, Bennett pointed out. Even how much dust is a hazard is still unknown. (A large number of solid substances become explosive when in the form of a fine dust, OSHA says. These substances include organic materials, such as grain, sugar, wood, and coal; synthetic organics, such as plastics, dyes, foams, pharmaceuticals, and chemicals; and combustible metals, such as aluminum, magnesium, zinc, and iron.)

Generally speaking, the smaller the dust particle, the bigger the hazard. According to OSHA, an often-used rule of thumb is that dust of 420 microns particle size (40 mesh sieve) may serve as the fuel in a dust explosion. As a frame of reference, normal table sugar ranges from about 850 microns to 150 microns, with the bulk of sugar between 350 and 450 microns.

During his presentation, Bennett provided tips and methods for mitigating and controlling dust within facilities. Repeated points throughout his presentation include: Test your own dust with equipment that’s currently on the market. And because layers as thin as 1/32 of an inch (0.8 millimeters) or 1/16 of an inch (1.6 millimeters) can be problematic, “if you see dust, don’t ignore it. Instead, clean it, and examine where it’s coming from,” he said. Also, seal all openings in equipment to prevent the release of dusts into the work environment, he said. “The point is, stay on top of this issue before it lands on top of you.”

This entry was posted on Tuesday, February 9th, 2010 at 2:00 pm and is filed under Equipment, Manufacturing and Processes, Reducing Emissions. You can follow any responses to this entry through the RSS 2.0 feed.