Scorecard: Combustible Dust Explosions/Fires March 2008

March was a busy period for combustible dust explosions and fires at manufacturing facilities totaling 14 incidents, which included seven combustible dust explosions at wood, food, metal, power generation, and feed industries. In contrast, at grain facilities there was four combustible dust related incidents, which included one explosion. Luckily there were no fatalities and limited to one injury. The negative economic impact to the local communities has been the most damaging aspect of these preventable and predictable accidents.

Most troubling is the repeatable combustible dust related explosions and fires that have occurred in 20% of the incidents. For instance, a metal finishing facility in Michigan had combustible dust fires occur in their dust collectors twice within one week. In the second fire, employees emptied all 18 of their fire extinguishers to quench the flames.

Hazardous Communication
The majority of the workforce, management, and owners have no idea of the combustible nature of combustible particulate solids when combustible dusts are generated during the manufacturing process. Combustible dusts forming an explosive atmosphere can be equated to flammable vapors that occur in a transfer operations between petroleum barges and a refinery during a marine transfer of flammable liquids. For example, when the transfer hose is connected or disconnected from the barge, flammable vapors are present from the flammable liquids, which generates a potential explosive atmosphere.

Petroleum refinery operators have material safety data sheets which inform the workers of the flash points of the flammable liquids they are working with. In contrast, industries that handle wood, metal, feed, plastic, and other solids have no information in their material safety data sheets concerning the minimum ignition temperatures and minimum explosive concentrations of the combustible dusts that are generated from the combustible particulate solids they are handling.

Explosive Atmospheres
Explosive atmospheres are just as easily formed when working with combustible particulate solids as when handling flammable liquids. In both instances combustible dusts and flammable vapors are generated creating a hazardous environment. Preventive and mitigative measures must be instituted to protect the worker, facility, and community from catastrophic events that could occur if proper administrative and technical measures are not followed.

Currently it's safer to work in a chemical or petroleum plant as the petrochemical industry is already aware of the hazards and follows proper procedures. In contrast general industry has no comprehensive procedures in the safe handling of combustible particulate solids and the combustible dusts that are formed in the manufacturing process.

This is where the disconnect is over the last eight weeks with the nationwide 27 combustible dust related explosions and fires since the tragic Imperial Sugar Refinery combustible dust explosion in February. There would be public outrage if there were 7 refinery and chemical plant explosions over the month of March. But no outrage at all with the combustilbe dust explosions.

Trade Associations
Its time for all trade associations in general industry to create preventative and mitigative technical and administrative procedures concerning combustible dust hazards. This information can be shared collaboratively with it's association members in the prevention of future accidents.

For instance, material safety data sheets can be amended in providing fire and explosive hazards of combustible dusts. On the company level this would prove costly, whereas on the larger association level the costs can be reduced in amending material safety data sheets with a collaborative effort between its association members that handle the same raw materials in the manufacturing process.

Ignition Sensitivity
Additionally, at the trade association level, testing can be proactively instituted in determining the ignition sensitivities and explosive severity of the combustible dusts that are generated in the manufacturing process of combustible particulate solids. The current reactive measure that OSHA has in it's National Emphasis Program for combustible dusts does not provide industry with proper proactive preventive and mitigative measures.

Due to budget constraints, there are a limited number of OSHA inspectors in collecting samples and sending obtained dusts to the OSHA Salt Lake Testing Facility. Who is going to pay for these very expensive tests? What about the time in between when the facility might have an inspector arrive? Where is the protection in between ? The clock is ticking and only more preventable and predictable combustible dust related explosions and fires will occur until industry moves proactively.