Upside Down Combustible Dust Bill

Dust explosions garnered national attention this week with the catastrophic coal dust explosion at a Wisconsin coal-fired electrical energy plant in conjunction with the reintroduction of the combustible dust bill. While it is undisputed that worker protection is needed concerning combustible particulate solids that generate combustible dust in the manufacturing, non-manufacturing, and grain sectors. A question arises in the protective measures outlined in H.R. 849, “The Worker Protection Against Combustible Dust Explosions and Fires Act,” requiring the U.S. Occupational Safety and Health Administration (OSHA) to issue rules regulating combustible industrial dusts.

Stakeholders throughout the industrial sectors including the public must realize that dust explosions can never be totally prevented unless we completely shut down our manufacturing base and turn into a service based economy. For instance, we can learn from our New Zealand trading partner, where proactive dust explosion control measures are in place in protecting local and export industries.

Since instituting these control measures the amount of dust explosions have been constant as previously occurred without control measures. The only difference is the severity of these incidents have been reduced with measures like explosion venting and deflagration suppression best engineering practices.

Propagating Explosions
Combustible dust explosions follow under the subheading of propagating explosions quite similar to vapor cloud explosions in the refinery and petrochemicals sector where a combustion zone propagates at subsonic speeds wrecking havoc with the damaging effects of overpressure, thermal radiation, and ensuing projectiles. In March 2005, the catastrophic BP Texas City Refinery explosion is an example of a propagating vapor cloud explosion with similar damaging effects like the Imperial Sugar Refinery propagating dust explosion in February 2008.

Developing worker protection legislation in regards to combustible dust explosions as written in the current reintroduced bill fails to take into account many important aspects in providing basic layers of protection for the nation’s workforce. Additionally, solely utilizing the Chemical Safety Boards (CSB) recommendations as a template for the bill without taking into account many other life saving aspects of protection will not fully solve the problem of future incidents.

A good example is the recent catastrophic We Energies coal dust explosion that utilized national consensus National Fire Protection Association (NFPA) combustible dust standards as stipulated in the combustible dust bill, while implementing explosion control measures such as explosion ventilation panels that reduced the severity of the explosion. NFPA combustible dust standards provide excellent guidance in preventing and managing combustible dust fires and explosions but only to a certain level.

Not in Vicinity/In Vicinity Protection
Subsequently, there only so much that can feasibly be done in providing protection concerning life safety, structural integrity, and mission continuity. For instance, the NFPA combustible standard’s primary objectives are to protect occupants not in the immediate vicinity of an explosion and fire. The contractors that suffered burn injuries in the Wisconsin coal dust explosion were in the immediate vicinity and this is where the problem arises in the reintroduced combustible dust bill in not addressing other important issues.

A potential solution in addressing worker protection concerning combustible dust explosions and fires is incorporating key aspects of the OSHA Process Safety Management (PSM) standard. This might be difficult for many to envision since the PSM standard centers around over 130 highly hazardous chemicals (HHC) that are toxic, corrosive, and reactive.

Combustible dust does not fall into any of these categories. But is does fall under one category in the PSM, and that is the explosive effects quite similar to flammable liquids and gases that can cause propagating explosions. Laying aftermath pictures side by side of the BP Texas City incident and Imperial Sugar Refinery explosion would be difficult for many not familiar of the specific processes to differentiate the two. Both caused severe loss of life, injuries, and property damage.

Contractor Awareness
The OSHA PSM does address contractor participation such as ensuring that contractors attend training concerning the hazards of the perspective workplace. Since contractors work in the immediate vicinity of fire and explosion hazards the PSM standard would provide an appropriate basic layer of protection, where the NFPA combustible dust standard does not, with the conflicting objective of occupants not in the immediate vicinity. Why can’t all layers of protection be crafted into the combustible dust bill?

Better yet, instead of another form of costly regulation that creates an administrative overburden requiring a force of over 10,000 OSHA inspectors for implementation, formulate combustible dust workplace protection around the current OSHA Process Safety Management standard (PSM). There is no need to differentiate another propagating explosion as a separate entity when the issue has already been addressed with flammable gases in the current OSHA PSM standard.

In fact many dusts have deadly overpressure effects more damaging than flammable gases. So what’s the difference and why so much of a disconnect? Is loss of life, injuries, and adverse economic damage more important of an issue in the PSM refinery sector than in the manufacturing sector? It’s time the same level of protection be provided for all the nation’s workers.

Layers of Protection
Combining the protection measures of the national consensus NFPA combustible dust standards and the OSHA PSM standard would go a long way in providing appropriate layers of protection. Already the NFPA combustible dust standard outlines process hazard analysis, process safety information, management of change, and many other criteria quite similar to the current PSM standard.

It doesn’t make sense to reinvent the wheel when the protection measures in the current OSHA PSM could provide an excellent guidance in providing workplace protection for the manufacturing and non-manufacturing sectors concerning combustible dust, just like it currently does for the refinery and petrochemical sector. When many stakeholders fail to take into account, is that all the above falls under the same umbrella of propagating explosions.

Fires Now Explosions
To further complicate the confusion of combustible dust hazards is the profusion of misinformation that the media has recently been expounding on concerning over 350 combustible dust explosions since 1980. For instance, after the CSB Combustible Dust Hazard study, submitted to OSHA in 2006 it was 281 combustible dust explosions and fires from the 1980-2005 period.

Then after the June 2008, CBS 60 Minutes segment on combustible dust, the fires from the CSB Dust Hazard Study, all of a sudden evolved into explosions, with the fires not being reported through many media sources. Hence adding to misinformation like a propagating combustion zone where soon the next media outlet, like unreacted dust ahead of the reaction front, will be consumed with more misinformation.

Conflicting Research Data
Most of the combustible dust incidents are fires not explosions. For instance out of the over 150 incidents in 2008 occurring in the manufacturing and non-manufacturing sector only 30 were combustible dust explosions. But don’t get a false sense that this is a mediocre number, since many dust explosions where previously combustible dust related fires, months earlier in prior repeatable incidents.

Incident reporting as stipulated in the OSHA PSM standard would provide stakeholders with a better idea of the probability and severity of occurrences instead of solely relying on incomplete data from governmental and media reports in formulating occupational health and safety policy

Conclusion
There are many more aspects in formulating a solution in developing comprehensive occupational safety measures concerning the hazards of combustible dust in the workplace. Hopefully a few of the above issues will provide insight into the depth and breadth of the issue that at times is like peeling back the many layers of an onion.

The reintroduced combustible dust bill needs to be rewritten to incorporate all layers of safety and not just from the 30,000 foot view following the tragic Imperial Sugar Refinery dust explosion. The future of our nation’s workforce is at stake. Instead of the threat from outside as in Homeland Security regulations, we now have a threat from within. Question is, just how much resources we are all willing to put forward.

Dust Explosions Public Relations Priorities

Over that past couple weeks several dust explosions have occurred in facilities throughout the United States. These events mostly go unnoticed by the national media unless there are a multitude of injuries or fatalities like the recent coal-fired energy plant in Wisconsin that sustained a dust explosion in the dust collector, where several contractors sustained burn injuries.

Congressional leaders where quick to respond with a press release after the Wisconsin coal dust explosion with Representative Lynn Woolsey (D-CA), chair of the Workforce Protections Subcommittee, stating that, “ yesterdays accident was just another reminder of the unacceptable risk posed to workers by outdated regulations on combustible dust,”

This knee jerk emotional response to a multi-dimensional problem of dust explosions throughout our nation’s industrial sector where fuel and ignition sources are continually present does not fully address workplace protection measures that already are in place.

National Consensus Standards
For example, We Energies, the facility where the coal dust explosion occurred had already instituted proactive protective measures with national consensus good engineering practices in minimizing the probability and reducing the severity of dust explosion as outlined in the National Fire Protection Association (NFPA) combustible dust standards. Reading in between the lines of many news accounts the reader will find mention of explosion ventilation panels that vented the harmful overpressure effects of the explosion to safe levels, preventing the duct collector from fragmentating like a hand grenade.

Explosion ventilation panels ensure that after an explosion, life safety, structural integrity, and mission continuity of a facility is maintained. Unfortunately life safety was breached with the burn injuries to the contractors, yet the facility continued functioning in providing electricity to its customers. There is always a risk to workers when handling combustible particulate solids that generate combustible dust in the diverse spectrum of industries and injuries cannot be totally prevented, only minimized as was the case in this incident where fortunately there were no fatalities on site.

Reintroduction Combustible Dust Bill
Most importantly, the protective and mitigative control measures that We Energies utilized in protecting the worker from harm is in the same content of the recently reintroduced congressional bill that was initiated last year following the Imperial Sugar Refinery dust explosion. The Worker Protection Against Combustible Dust Explosions and Fires Act, H.R. 849, will require the U.S. Occupational Safety and Health Administration to issue rules regulating combustible dust in industry. The bill explicitly states that the proposed rules would be based on effective voluntary standards devised by the National Fire Protection Association. Ironically, We Energies are following the rules. So what outdated regulations on combustible dust, is the Congresswoman referring too?

Facilities that sustain dust explosions where injuries and fatalities occur are best served in providing complete transparency to the public, as We Energies has done, in sharing information to the media concerning protective administrative and engineering control measures that have been implemented such as the case with the explosions ventilation panels. Many coal fired electrical energy plants throughout the nation are collectively addressing combustible dust hazards through the PRB Coal Users Group in which We Energies and many other plants are alliance members.

Combustible Dust Industry Awareness
Most recently, several members of this alliance attended the Combustible Dust Hazard Awareness workshop, hosted by the Combustible Dust Policy Institute at the 4th Annual Industrial Fire, Safety, Security Conference in Houston, Texas February 3-6 2009 in the Reliant Center (next to the Astrodome). In addition to understanding how to identify, evaluate, and control combustible dust hazards at a facility, it is equally important after a major incident to provide the media essential information concerning the proactive control measures that were utilized.

Without this information, a negative reaction is likely to occur as is the case with the recent congressional press release that provides the public with an inaccurate depiction of the events. The Combustible Dust Policy Institute, with a diverse knowledge of combustible dust incidents and regulations, can assist all stakeholders when major catastrophic incidents occur in working collectively with public relations personnel in the development of positive proactive post incident media response.

Photo Credit: Enrique Rodriquez-Journal Sentinel

Resources:
Oak Creek Power Plant expansion
Journal Sentinel- excellent news coverage

Dust Explosion Suppression Implemented

Staubexplosions (dust explosions) are in the news again but in a good way. Kraiburg TPE, a German company, which manufactures thermoplastic elastomers (TPE) products based on HSBC (hydrogenated styrene block copolymers) has shared with all industry stakeholders the preventative and mitigative control measures implemented at their facilities in reducing the severity of dust explosions.

The informative article "Playing it Safe," notes that of over a thousand different materials utilized in the various Kraiburg TPE manufacturing processes, approximately 50 are characterized as combustible dust. To address the potential combustible dust explosive atmosphere in the plant, Karl-Heinz Ortmeier, project manager at Kraiburg TPE initiated a thorough process hazard analysis (PHA).

Subequently, after conferring with fire protection engineers concerning the results of the PHA, Kidde, a global leader in fire/explosion protection, installed an explosion suppression system in the plant. The system includes explosion pressure sensors, detecting an initial explosion, which then transmits the signal to a detection and control center, were next the HRD (High Rate Discharge)-cylinder is activated suppressing the verpuffung (deflagration) with sodium bicarbonate in milliseconds.

It's not to often where such transparency is offered for others to witness and maybe think about what dust explosion methods are utilized at their manufacturing facility. NFPA 654 " Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids," has an excellent section in the Annex concerning explosion suppression that is a must to read.

For many of us not yet fluent in German, use the Google Toolbar to translate the very informative "Playing it Safe," article.

Staubexplosion German Pellet Mill

Here is an interesting global update with a dust explosion (staubexplosion) at a wood pellet mill in Ettenheim, Germany that occurred January 4. Use the Google Toolbar to translate from German to English for the rest of the story, as Paul Harvey would say. It's interesting to note how well versed the news reporter is in reporting that a dust explosion occurred while providing readers detailed information about the process equipment where the explosion originated, the hammer mill.

Last year in the United States, nearly a half a dozen combustible dust related fires and explosions occurred in wood pellet plants within a short time span of three months. Of the over 150 combustible dust related explosions and fires that the Combustible Dust Policy Institute found through media reports in 2008 at manufacturing facilities, most of the time there's never a headline like in the German online article where the incident was actually a dust explosion (staubexplosion). Instead in our regional news, readers must carefully search for key words as the reporter describes the fire or explosion. Such as a fire in the ductwork or explosion in the dust collector.

An exception to news reporting of dust explosions in the United States occurred January 20, 2009 when news reporter Cara Spoto of the Freeport, Illinois Journal Standard, reported on the dust explosion at an Ethanol plant in Monroe, Wisconsin. One does not easily find news reports like this describing the event in such detail and even mentioning the dryer. Quite similiar to the mention of the hammer mill in the German wood pellet mill dust explosion

Most revealing, the term deflagration (verpuffung), was used three times in the informative article. A deflagration is rapid subsonic combustion where there is also a rapid rise in pressure and heat. There's good deflagrations, like the reusable solid rocket boosters when the Space Shuttle launches with the assistance of over 320,00 lbs of micronized aluminum dust and of course there is bad deflagrations that we sometimes read about in the news with dust explosions occuring in a diverse spectrum of industry.

Many fires and explosions that occur in the manufacturing and non-manufacturing sectors that are combustible dust related never get reported as such, since reporters and the general public are not yet knowledgeable about deflagrations. It's difficult enough to say the word without getting tongue tied. Much less acknowledge that products on the supermarket aisle, so harmless as milk powder and dairy creamer can level a production facility, causing fatalities and injuries.

German research scientists have been studying dust explosions for over a century and have assisted their global trading partners with the wealth of knowledge they have acquired. Check out the GESTIS-DUST-EX database on the German BGIA - Institute for Occupational Safety and Health website for ignition sensitivity and explosion severity data of more than 4,000 dust samples from a multitude of sectors.

Its interesting to note that the deflagration index Kst, in regards to testing for explosion severity in the laboratory also has German roots, as the subscript (st) denotes staub, the German word for dust, thus staubexplosion. So remember next time you turn the ignition with your keys to start your car, your having a good verpuffung when the fuel-air mixture in your engine ignites creating a good deflagration transforming chemical energy into useful mechanical energy for the daily commute to work or run errands in town.

Industry Leader Mitigates Dust Explosion

Badger State Ethanol an industry leader provides an excellent example how best engineering practices in reducing the severity of dust explosions can be utilized in preserving life safety, structural integrity, and mission continuity following the recent combustible dust related fire and explosion at it's Monroe, Wisconsin ethanol plant.

An excellent news report by Cara Spoto of the Freeport, Illinois Journal Standard describes how a fire originating in the dryer after a dust explosion spread to the ductwork. Firefighters from surrounding communities successfully battled the blaze in subfreezing weather and damage was kept to a minimum according to General Manager Gary Kramer.

The most interesting and educational aspect of the story, is mention that explosion ventilation panels successfully reduced the severity of the incident. Additional information on best engineering practices in preventing and mitigating combustible dust related fires and explosions in dryers can be found in the NFPA 86 Ovens and Furnace Standard and NFPA 61: Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities,

Over the past year, through media accounts, there's been over a dozen combustible dust related fires and explosions in the nation's 172 operating ethanol plants. The Combustible Dust Policy Institute has found that over 50% of these incidents have occurred in the dryer. The United State is not alone where combustible dust related fires and explosion are occuring at ethanol plants. Last month, at Manildra, Australia's largest ethanol distillery in New South Wales experienced a dust explosion in the dryer that also was successfully mitigated with explosion ventilation panels.

According to the excellent text, Handbook of Industrial Drying 3rd edition, edited by Arun S.Mujumdar, data has indicated that the accident rates concerning dryer fires and explosions is prevalent on a global basis. It's only when proactive preventative and mitigative measures are implemented as outlined in the National Fire Protection Association combustible dust standards that the probability and severity of the occurrence is substantially reduced.

For additional information on identifying, evaluating, and controlling the risk from combustible dust related fires and explosions throughout industry, be sure to attend the Combustible Dust Hazard Awareness workshop at the 4th Annual Industrial Fire, Safety, and Security conference (IFSS 2009), Feb. 3-6 2009 at the Reliant Center (next to the Astrodome) in Houston, Texas. Call (832) 242-1969 for additional information.

Dust Collector Explosion Protection-Webinar

Tomorrow at 12:00 NOON (EST) Gary Johnson, an experienced industrial ventilation and process safety consultant will be presenting a two hour webinar on "Dust Collection: Dust Collector Explosion Protection/Prevention Options,"moderated by Robert Harkin, Associate Editor of Powder and Bulk Engineering.

After the webinar, attendees can e-mail questions and comments. Thats a great deal for $50. Especially since over 50% of combustible dust related fires and explosions in 2008, through media accounts, have occurred in the dust collector. Don't find out the hard way that the dust collector at your facility can possibly create some costly downtime without the proper preventative and mitigative fire/explosion control measures. This is a great way to start the new year out right.

In the meantime be sure to check out the multitude of educational resources that can be found online at Powder and Bulk Engineering. and Gary's website Workplace Exposure Solutions LLC

Resources
Gary Q. Johnson-Workplace Exposure Solutions LLC
Dust Collector Webinar
Webinar Registration $50
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