Here is a short video simulating a combustible dust explosion in a silo or bucket elevator where the explosion panels take the brunt of the blast. The end result would be the protection of property and personnel.
Monday, April 7, 2008
Thanks to all the visitors who have ended up on the Combustible Dust Explosion and Fire blog. I know now that the efforts in providing helpful information regarding combustible dusts have not gone in vain. It be sort of strange making posts and no one reading them ...sort of like talking to myself.
Since the first post on March 1, I've learned quite a bit and learning more everyday about the various manufacturing processes that handle combustible particulate solids that generate combustible dusts. Every process has it's unique characteristics in generating combustible dust and it's important that the plant manager obtain an awareness of this complex subject and share this knowledge with all the employees in the company health and safety training program.
When I see Google search terms come up, such as minimum explosive concentration of grain dust, combustible dust testing, kst index coal, combustible wood dust in shop, and corn dust msds. Then I know viewers are actively seeking to acquire information in the prevention and mitigation of future dust incidents. Hopefully this Combustible Dust and Fire Explosion blog will provide an easy pathway in obtaining the information you seek.
Thanks again for visiting the site and be sure to leave your comments following the posts. That would help in generating constructive dialog on the subject. If the music that I added to the site becomes to irritating you can just click the pause button at the top left of the page.
Being that many blue-collar workers in the manufacturing industry work the shift schedule I figured it would be appropriate to add Kenny Chesney's song "Shiftwork" to the site. That what this site is all about...protecting all workers from the consequences of combustible dust explosions and fires, whether they work shift or not. It doesn't help that unfortunately I work shift also. So when I first heard the song..I thought yeah, I can relate to that. So for others who don't work shift you are not missing anything. But now you have an idea of what it's all about while you browse the contents of the site.
Over the past eight weeks since the tragic Imperial Sugar Refinery combustible dust explosion I've been busy seeking any information that is available concerning the causes and prevention of combustible dust fires and explosions. One subject that has come up is minimum ignition energy (MIE), which is the energy in millijoules from electrostatic discharges or static electricity that can ignite combustible dusts generated from combustible particulate solids in the manufacturing process.
An excellent book published by the American Institute of Chemical Engineers is "Electrostatic Ignition of Fires and Explosions" by Thomas H. Pratt . This book is an easy read and no prior background in engineering is necessary, which enables everyone in obtaining an understanding of static electrical hazards in the workplace.
The chapters start out with basic concepts then moves on to accumulation, separation, and discharge of electrical charges. Once that concept is mastered, minimum ignition energies can be grasped into how they apply in the workplace. As the book progresses, the author takes the reader into various areas in the manufacturing process dealing with liquids, mists, and finally powders.
With the idea of how static electricity originates the reader is presented with design and operating criteria in addition to electrostatic measurements, and quantification of electrostatic scenarios. Finally at the conclusion and last chapter case histories are provided where the reader is actually able to see how combustible dust explosions and fires occurred when minimum ignition energy ignited dusts.
For many including myself I had no idea what the terms propagating brush or brush discharges meant in regards to minimum ignition energy. Prior to reading the book I thought brush discharges had to do with brushes in an electircal motors but that is not so.
If you have combustible dust in the workplace in any form it's imperative that you understand what minimum ignition energy is. Especially since in the material safety data sheets (MSDS) of the explosive and fire hazard section, this property is not listed like flash points are listed for flammable liquids.
They don't mess around when it comes to plant explosions in Belgrade, Serbia. An explosion over the weekend at a pesticides storage facility put 29 people, mostly firefighters in the hospital. The Environmental Ministry is filing criminal charges against the responsible person. Is it possible that someone high in management could be sitting in a courtroom soon explaining why the incident occurred and what preventive and mitigative measures the facility had?
I wonder how far plant explosions would be reduced in the United States if criminal charges where filed by governmental entities immediately after an explosion? It's great here in the United States that criminal charges are really not considered after the majority of events, just a small fine and slap on the wrist. Fatalities and injuries in the cost benefit analysis are cheaper than voluntary administrative and technical preventive and mitigative measures. Thankfully we live in a free country of laissez faire.
The six combustible dust explosions last month is not limited to incidents in the United States. Over the weekend a combustible dust explosion occurred at Associated Proteins, in Ste Agathe, Canada. Associated Proteins, a canola processing facility, and the largest expeller-pressed oilseed crushing plant in the world has a state-of-the art facility which has gone to great expense to ensure the most cutting edge technology is used in their manufacturing process. An educational video concerning the canola manufacturing process can be viewed on their web site.
So how can a plant that is so clean experience a dust explosion? Poor housekeeping is out of the question. OSHA's mantra concerning the prevention of future combustible dust explosions and fire is good housekeeping. True, housekeeping is important, but this is only one priority and that is where the current OSHA voluntary program fails miserably in preventing future combustible dust explosions and fires.
The pathways concerning the molecular fragments that generate a combustible dust explosion and fire are more complex that just housekeeping. In any manufacturing process electrical charges are constantly being separated, accumulated, and dissipated in the form of electrostatic discharges or static electricity. At this level it doesn't take much to ignite a cloud or layer of combustible dust generated from combustible particulate solids of metals, food products, wood or plastics. So even if good housekeeping is adhered to the potential for an incident persists as dusts are inherently part of the process where an potentially explosive atmospheres coexist.
It would turn into a terrible day at petrochemical plants if the explosive atmospheres from flammable vapors were ignored like is the case with combustible dust. Think explosive atmospheres....combustible dust and flammable vapors. It's all the same yet that is where the disconnect is here in the United States. Yet the majority of stakeholders do not believe combustible dusts can provide an explosive atmospheres on a regular basis.
MSDS Information Nonexistent
On the other end of the spectrum there are facilities that accumulate combustible dusts in the manufacturing process and are not aware of the hazards involved. Just last week, Quality Cushion and Pad in Georgia experienced a combustible dust fire that destroyed the facility where housekeeping was questionable according to the news report.
If the proper information on the fire hazards such as minimum ignition temperature, minimum explosive concentrations, and minimum ignition energy were included in the Material Safety Data Sheets (MSDS), incidents like this could be prevented. The big question is, who's responsibility is it to include this vital information in the MSDS...the raw product supplier or the company? In this case, that could be quite complex since this facility receives millions of pounds of recyled polyurethane foam by the truckload from thousands of sources.
Explosion Protection Document
Combustible dust explosions and fires are a global problem. Our global trading partners in the European Union, United Kingdom, Australia, and the New Zealand are already addressing the problem with the requirement that facilities develop an explosion protection document. The recent example of the unfortunate Canadian incident highlights that poor housekeeping is not the sole cause of combustible dust explosions and fires.
It's time that all facilities in the United States large or small review the combustible dust hazards in their workplace and prepare their own explosion protection document. If you don't know the minimum ignition temperature (MIT) or minimum ignition energy (MIE) of the combustible dust at your facility then please find out now. Until then you are on borrowed time.
The House Education and Labor Committee will vote Wednesday, 9 April on the Combustible Dust Explosion and Fire Prevention Act (H.R. 5522). Earlier on 12 March a hearing was held concerning pending legislation in response to the recent Imperial Sugar Refinery explosion in Georgia and OSHA's failure to act on comprehensive a combustible dust standard in general industry as recommended by the Chemical Safety Board.
Since the February 7 Imperial Sugar refinery explosion there has been 29 combustible dust fires and explosions in general industries throughout the United States, which doesn't include grain handling facilities. Facilities which handle grain must comply with the OSHA grain handling combustible dust standard that was implemented in 1988. Prior to the OSHA grain standard there were numerous combustible dust fires and explosions resulting in preventable fatalities and injuries. Over the past two months there has been nine combustible dust fires and explosions at grain facilities, which includes three explosions.
National Fire Protection Association
For nearly a century the National Fire Protection Association has formulated fire codes in the protection of property and personnel. Several of these fire codes deal with metal, food, wood, and agricultural combustible dusts. In contrast, the majority of state fire marshals have not implemented these combustible dust fire codes in their inspection protocol and thats where the main problem is concerning the continual occurrence of preventable and predictable combustible dust fires and explosions.
The Combustible Dust Explosion and Fire Prevention Act (H.R. 5522) will require that the National Fire Protection Association's Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids-2006 (NFPA 654) and Standard for Combustible Metals-2006 (NFPA 484) be adhered to by all states whether or not such protection is already incorporated in state fire codes.
National Emphasis Program
OSHA has instituted a voluntary National Emphasis Program for combustible dusts since October 2007 that has not offered the protection in the prevention of future incidents. For example, the program guidelines direct OSHA inspectors to obtain dusts samples for analysis at the OSHA Salt Lake Testing facility in the determination of the ignition sensitivity and explosion severity of dusts generated at a facility. This is a backward approach since thousands of manufacturing plants are already generating combustible dusts in their processes and waiting for a inspector to arrive is a recipe for disaster as can be seen in the Imperial Sugar refinery resulting in 13 fatalities.
Opposing Passage of Bill
Opponents of the Combustible Dust Explosion and Fire Prevention Act (H.R. 5522) feel that a congressional mandate in preventable combustible dust explosions and fires is to rapid of an approach and more input needs to be addressed between regulators, industry, state fire marshals, trade associations, and labor organizations. Additionally, opponents of the pending bill believe that a "one size fits all" covering combustible dusts across a wide spectrum of industries will lead to problems in the interpretation of an OSHA comprehensive combustible dust regulation.
The national consciousness of preventable combustible dust explosions and fires have yet to be aroused in between the presidential primaries and only a small minority of stakeholders vocally desire the passage of a combustible dust bill. With House committee members politically divided between the interests of labor and industry, movement of the bill to the house floor will be an uphill battle for the proponents.
Text of Bill