New-England-Wood-Pellet-combustible-dust-fire-explosion

A massive fire and explosion in the dust collection system of a New Hampshire wood pellet manufacturer demonstrates the need for adequate system design to prevent combustible dust explosions in general industry.

By Dominick DalSanto
Baghouse Technology Expert and Sales Director
Baghouse.com

May 16 2012 – Baghouse.com Editorial | On October 20 2011, a combustible dust fire began in the wood pellet cooler, most likely caused by a spark or ember from the pellet hammer mill. The fire then spread through the ductwork throughout the plant, eventually reaching the dust collector causing it to explode. When the collector exploded, the explosion vented through the baghouse’s explosion vents into adjacent storage silos setting them ablaze further spread the fire throughout the plant. More than 100 firefighters and emergency personnel from at least 14 towns worked for over 15 hours to put out the blaze.

The OSHA report outlines specific areas where the plant lacked adequate spark detection devices, fire suppression systems, and explosion venting/protection within the dust collection system. The fact that the plant had been cited by OSHA for several of the same issues previously after a 2008 incident, led to OSHA assessing total fines of $147,000.

Examining what went wrong in this incident highlights the need for diligence on the part of plant management and operators regarding the dangers of combustible dust.

What Went Wrong?

The October 20 2011 fire and explosion at the Jaffrey, NH plant was not the first combustible dust related incident at the plant. In 2008 the plant experienced a similar fire and explosion that caused more destruction than the most recent one. After completing its investigation, OSHA at that time fined the plant over $100,000 for safety violations that led to the fire. Subsequently, the plant, in an attempt to prevent another such occurrence, “retained engineers and consultants, and spent over $2 million on various improvements to enhance worker safety at its Jaffrey facility” according to a release from the company. This apparently including the installation of some explosion isolation devices in the ductwork (Rembe explosion isolation device) and installed explosion protection (explosion vents) on the baghouse. However the company’s effort and expense failed to prevent another incident from occurring.

Fire fighters work to put out a massive blaze caused by a destructive combustible dust fire and explosion at the New England Wood Pellet Company's Jaffrey, NH facility.

Fire fighters work to put out a massive blaze caused by a destructive combustible dust fire and explosion at the New England Wood Pellet Company’s Jaffrey, NH facility.

The OSHA report is quite thorough in its description each poorly designed, installed and operated part of the dust collection system either caused or intensified fire and subsequent explosion.

For example the report cites the plant for 2 main offenses. The first one is regarding poor housekeeping throughout the plant that led to large accumulations of combustible wood pellet dust forming on top of machinery (such as the pellet cooler where the fire began) and on elevated surfaces such as overhead rafters, ceiling joists, troughs, etc. Secondly, and more seriously, the plant was cited under the General Duty Clause of the OSHA Charter* for failing to take reasonable steps to prevent a combustible dust fire/explosion from occurring. OSHA cited several industry standards such as the National Fire Protection Association building code that the plant failed to heed in the design and construction of the plant’s dust collection system.

Ductwork Lacked Sufficient Spark Detection, Fire Suppression, or Explosion Isolation Devices

A major oversight in the ductwork system, was the lack of appropriate spark detection, fire suppression or fire isolation devices on all of the ductwork between the various machines throughout the plant. For instance, OSHA reported that the connecting ductwork between the pellet hammer mills, the pellet cooler, the bucket elevators storage silos and most of the dust collectors in the plant had no spark detection system, fire suppression system, or explosion isolation devices installed. The only control device the plant had was an explosion isolation device on the conveying duct between the pellet cooler and the pellet cooler baghouse. However, the device did not function properly and allowed the fire to propagate further downstream into the baghouse.

NFPA 664 (2012) Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities: 8.2.1. and Hazard Determination 8.2.4.1. – Conveying systems with fire hazards should be isolated to prevent propagation of fire both upstream and downstream (OSHA isolation can mean spark detection and suppression). 5.2.5.1 Prevention of Fire Extension: When limitation of fire spread is to be achieved the following criteria shall be demonstrated…(4) Particulate processing systems (dust collection systems) shall be designed, constructed, equipped and maintained to prevent fire or deflagration from propagating from one process system to an adjacent process system.

Additionally, the ductwork was not engineered and/or constructed to sufficient strength to withstand the maximum anticipatable explosive pressure resulting from a conflagration involving its intended payload (combustible wood dust). This led to the duct bursting open, releasing the explosion into the plant near firefighters and may have been a contributing factor in the fire by-passing the isolation device.

NFPA 664 (2012) 8.2.2.2.3, Sets forth alternative safety criteria for ducts with a deflagration hazard, to ensure that the ducts are builds with a sufficient strength and with appropriately sized/located protection devices to handle the maximum expected pressure generated by a dust explosion. 

Baghouse Was Not Adequately Protected Against Explosion Hazards

The plant recently installed explosion vents on the baghouse explosion vents.* However, the design and installation of the explosion protection on this particular baghouse may actually made things worse than if there had been none at all.

When the fire reached the baghouse and caused the finely dispersed dust to ignite, the resulting pressure and fireball should have been vented outside the building. However, the explosion vents on the baghouse faced the direction of adjacent storage silos (containing wood dust). When the explosion was vented out it ignited the storage silos resulting in a major portion of the fire.

Additionally, OSHA’s investigation showed that the baghouse lacked an explosion suppression system, was not designed and/or constructed to withstand the maximum unvented pressure of a combustible dust explosion, and in the absence of proper explosion protection, was located indoors.

As a result of these failures, when the reached the dust collector, the resulting explosion: blew the dust collector’s door off its hinges, creating a missile hazard, blew backwards into the duct, which burst open, and blew out the dust collector’s exhaust muffler and roof stack, causing the pressure/deflagration to be vented inside the building near responding firefighters.

NFPA 664 (2012) 8.2.2.5.1.4. Requires an outdoor location for the dust collectors with fire or deflagration hazards, unless they are equipped with one of the following: (4) listed deflagration suppression system, (5) deflagration relief vents with relief pipes extending to safe areas outside the building and the collector meets the strength requirement of this standard (i.e. built with sufficient strength to withstand the maximum expected explosions pressure). NFPA 664 (2012) 8.2.2.5.3 requires dust collectors with deflagration hazards be equipped with an appropriate-sized explosion suppression system and/or explosion relief venting system designed per NFPA 68 (Explosion Protection by Deflagration Venting) and NFPA 69 (Explosion Prevention Systems), and also that such dust collectors be built to design strength that exceeds the maximum expected explosion pressure of the material being collected. NFPA 69, 12.1.2 requires “Piping, ducts, and enclosures protected by an isolation system shall be designed to withstand estimated pressures as provided by the isolation system manufacturer”. NFPA 69, 12.2.2.3 “System Verification” requires that systems shall be verified by appropriate testing under deflagration conditions to demonstrate performance.”

These design oversights directly increased the destructive power of what had until then been only a dust fire in the ductwork.

Lessons Learned From Wood Pellet Company Dust Explosion

Simply put, this disaster was bound to happen due to glaring design and/or construction flaws throughout the entire system.

The fact that multiple similar incidents have occurred at the facility demonstrates that the dust collection system, and perhaps even the entire production process requires modification to ensure this kind of incident does not occur again.

Under OSHA’s National Combustible Dust Emphasis Program, OSHA inspectors are on heightened alert for any combustible dust hazards in facilities in all industries. Indeed OSHA is under a federal mandate and its has as its own goal to issue a comprehensive combustible dust standard for general industry. In the meantime, OSHA has been citing plants under the general duty clause for having combustible dust hazards. In most cases, OSHA is informally requiring general industry to conform to the NFPA’s guidelines for combustible dust hazards. As seen in this case following they suggestions would have prevented this kind of incident from occurring.

Therefore, we can take away from this the need to be conscientious and proactive regarding combustible dust hazards in your facility. As we have seen, being reactive will simply not do.

Footnotes:

* OSHA General Duty Clause (a) Each employer — (1) shall furnish to each of his employees employment and a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees; (2) shall comply with occupational safety and health standards promulgated under this Act.

*  Baghouse Explosion Vents – Explosion vents are a form of explosion protection used on baghouses. During normal operation the vents are closed and maintain an air-tight seal. However, if an explosion occurs within the baghouse, the vents are designed to “strategically fail” being the weakest part of the baghouse structure, thus allowing the pressure from the explosion to vent out and away from other combustible materials and workers.

 

| Dominick DalSanto is an Author & Environmental Technologies Expert, specializing in dust collection systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as Sales Director at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.

Al Armendariz EPA

EPA chief resigns after outrage over comments saying EPA should figuratively “crucify” EPA offenders to set an example.

April 30 2012 – Baghouse.com News | A top EPA regional administrator resigned today over controversial comments regarding his views of how the EPA (Environmental Protection Agency) should enforce its environmental regulations, saying that the EPA should do like the ancient Romans who would crucify conquered villagers to set an example. Al Armendariz, the administrator for the EPA’s 6th region tendered his resignation after his remarks draw the ire of various members of Congress and the media.

In his letter of resignation to EPA Administrator Lisa Jackson, he expressed his regret over his statements, and claimed they did not reflect his work as an EPA administrator, or the EPA’s views general. However, he acknowledged that with the controversy his continued work at the EPA cause an undue distraction, and therefore he felt it necessary to resign.

At a local government meeting in Texas in 2010, Armendariz liked his “philosophy of enforcement” of EPA policy to how the Romans would use crucifixion to intimidate recently conquered lands. “It was kind of like how the Romans used to, you know, conquer villages in the Mediterranean,” he said. “They’d go in to a little Turkish town somewhere, they’d find the first five guys they saw, and they’d crucify them. And then, you know, that town was really easy to manage for the next few years,” he added.

Armendariz went on to related that “you make examples out of people who are in this case not complying with the law … and you hit them as hard as you can” — to act as a “deterrent” to others. He went on to say that the oil and gas industry needed to be an “enforcement priority” for the agency. The oil and gas industry along with the power generation industry have been coming under increased pressure from new and tougher environmental regulations such as the Cross-State rule, Mercury MACT, NESHAPs, and more. Many companies will need to make extensive investments in pollution control technologies such as dust collection systems, air scrubbers and mercury capture systems to comply with the new rules.

In accepting his resignation, EPA Administrator Jackson reiterated earlier sentiments that the EPA did not agree with Armendariz comments or views as expressed in his speech. “I respect the difficult decision he made and his wish to avoid distracting from the important work of the agency,” she said, thanking him for his service.

Critics Claim Remarks Are Evidence of Obama-EPA’s “Assault On Energy”

Critics of the EPA have taken the controversy as the latest proof that the “Obama-EPA” is playing partisan politics and is acting in bad faith to further the Administration’s alleged vendetta against the U.S. energy industry.

The controversy began earlier this week when Sen. James Inhofe (R-Okla.), a vehement critic of the Obama Administration (particularly on environmental issues) referenced the remarks in a speech on the Senate floor. Sen. Inhofe then proposed to launch an investigation into alleged politically-motivated bias on the part of the “Obama-EPA”.

Sen. Inhofe was not the only member of Congress to weigh in on the controversy. Several Republican lawmakers also expressed outrage and called for Armendariz to be fired including Reps. Steve Scalise (R-La.) and Pete Olson (R-Texas).

Rep. John Fleming (R-La.), called the comments “enviro-fascism at its worst.” The EPA’s Region 6 includes Louisiana, Texas, New Mexico, Arkansas, and Oklahoma.

House Speaker John Boehner (R-Ohio) reached out on Twitter, stating that the “Obama admin admits ‘crucify’ strategy for energy job creators.”

And Texas Gov. and recent Republican Presidential Primary candidate Rick Perry took the comments as “another reason to all-but-eliminate EPA” called the comments “unacceptable & offensive”.

Another top Republican, House Oversight and Government Reform Committee Chairman Darrell Issa (R-Calif.), plans to question EPA about the remarks. “He’s writing to EPA to seek clarification and express outrage with comments that are clearly at odds with the president’s prior comments on domestic energy production and that are clearly anathema to the cause of job creation,” a spokesman for Issa said.

In addition to lawmakers, several business and trade organizations are taking aim at the EPA over the controversy. Energy in Depth, an oil-and-gas industry group, is also highlighting the comments over Twitter and on its website, providing updates on the controversy including the calls for GOP members for his resignation. Other groups including the Business Roundtable and the Institute for Energy Research also took to Twitter to vent their feelings on the matter, criticizing the EPA and the Obama Administration.

The White House Denies Link To Armendariz Controversy – Cites Record As Proof

White House Press Secretary Jay Carney on Thursday called the comments at odds with the administration’s record of promoting oil-and-gas development and EPA’s approach. He pointed to increased oil and natural gas production in recent years as proof.

“The president’s approach, his all-of-the-above approach to our energy needs, I think documents and proves that those comments do not reflect his policy or the approach that the EPA has taken,” Carney said.

Carney also reiterated that the regional EPA official has apologized for the remarks. “What he said is clearly not representative of either this president’s belief in the way that we should approach these matters, or in the way that he has approached these matters, either from this office here in the White House or at the EPA,” Carney said at a press briefing.

While the ousting of Armendariz from his position is likely to be sufficient to reassure most, it is not likely to be the end of the matter. Given the serious implications of these words from a top level EPA administrator (one of the most important regions, the oil-rich South and Southwest), the Obama Administration’s tough stance on environmental issues, and role the booming U.S. oil fracking industry has in the nation’s future, ensure this issue will not go away. Republicans are likely to use this experience as a part of a continuing rally against Obama’s energy and environmental agenda…a fight that does not have a clear victor in sight.

 

| Dominick DalSanto is an Author & Environmental Technologies Expert, specializing in Dust Collection Systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as Online Marketing Director & Content Manager at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.

A factory that has been destroyed by a Dust Explosion

Nine years after the first of a series of deadly combustible dust explosions in the U.S., the CSB (Chemical Safety Board) is imploring OSHA to take decisive action and finalize its court-ordered Combustible Dust Standard. Investments in plant dust collection systems will be vital to meeting the new proposed standards.

April 4, 2012 – Baghouse.com News | Fed. 20, 2003, CTA Acoustics plant in Corbin, Ky, 7 dead; Feb. 7, 2008 Imperial Sugar Refinery in Port Wentworth, Ga, 14 dead, 38 injured; various dates in 2011, Hoeganaes powdered iron metal manufacturing plant in Gallatin, Tn, 5 dead in 3 separate incidents in 5 months. These are just a few of the deadly industrial dust explosions to occur in the U.S. over the last decade. In each of these incidents, the lives of these workers were tragically cut short by the seemingly-innocuous dusts present in the facilities.

The Chairperson of the U.S. Chemical Safety Board (CSB) Rafael Moure-Eraso, in a recent article has called attention to the fact that despite several deadly incidents occurring in the nine years since the CTA explosions, OSHA still has yet to follow through with its pledge to issue a comprehensive combustible dust safety standard for general industry.

Chairperson Moure-Eraso  relates the progression of events that lead to the CSB calling for OSHA to implement a comprehensive standard for combustible dust.  “The safety board launched a study into the hazards of combustible dust. Our 2006 report revealed there is no national regulation that adequately addresses combustible dust explosion hazards in general industry. Although many states and localities have adopted fire codes that have provisions related to combustible dust, a CSB survey found that fire code officials rarely inspect industrial facilities to enforce the codes. The board clearly stated that American industry needs a comprehensive federal combustible dust regulation.”

While the explosion at the CTA Acoustics plant in Corbin, Ky did lead the CSB to issue a number of recommendations to both plant management, local and state regulators, it was not until the 2008 Imperial Sugar Refinery explosion in Port Wentworth, Ga, that left 14 dead and 38 injured, that the CSB made its recommendation to OSHA to issue a “comprehensive combustible dust standard for general industry”.

The CSB is an independent governmental agency charged with investigating industrial chemical accidents. And while they do have limited authority to investigate and issue recommendations, they do not have the power to enforce safety regulations.

Despite its repeated recommendations to OSHA for the urgent need for hazardous dust standards, he relents: “ Yet, nine years after the CTA catastrophe, and more than five years after our recommendation to OSHA, there is still no comprehensive OSHA standard to prevent these accidents.”

After the CSB’s recommendations, OSHA in April, 2009 announced that it planned on issuing a comprehensive dust standard for general industry. However, its recent 2012 agenda does not include any specific mention of goals or targets for the development of the standard during the course of this year.

Will There Ever Be a Comprehensive Combustible Dust Safety Standard?

While the U.S. is still struggling to prevent these kinds of incidents from occurring, the rest of the world is not immune from them either. In fact, major manufacturers such as China, which often lack extensive safety regulations, are even more prone to experience these kinds of incidents. According to recent reports, last year saw two electronics manufacturers in China that produce parts for Apple Computer products experienced dust explosions when fine particles of aluminum ignited, killing four workers and injuring dozens of others. Apple’s Supplier Responsibility documents state that the company is now requiring improved ventilation, inspections and cleaning methods for dust deposits.

Without a standard that comprehensively addresses the hazards of combustible dust, American workers will continue to be put at risk for future catastrophic explosions and fires.

“I don’t know what steps China is taking to prevent its dust explosions, but I do know what can be done here in the U.S. It’s time for OSHA to move on a comprehensive regulation to adequately address combustible dust hazards” – stated CSB Chairperson Moure-Eraso.

What Does This Mean For U.S. Manufacturers?

While the current status of combustible dust regulation is not fixed on a federal level, (i.e. OSHA) the dangers of combustible dust still present a clear and present danger to both the financial interests of U.S. manufacturers and the lives of U.S. workers.

As a result of the long history of combustible dust explosions in the U.S. many state and municipal fire codes and other regulatory agencies already have combustible dust regulations for most industries.  In addition, many insurance providers are requiring plants as part of regular safety audits to improve dust hazard protection in their facilities as a condition of maintaining their coverage.

dust collection systems

Maintaining a sufficiently-sized dust collection system is vital to prevent combustible dust explosions.

The first step to preventing these incidents is recognizing the dangers combustible dusts present in an industrial setting. Measures to control or mediate combustible dust hazards include maintaining a adequate dust collection system (i.e. a baghouse), good house-keeping practices and good facility design.

A main contributing factor in all of the above mentioned incidents was an improperly operated or maintained dust collection system. From inefficient collection pickup points, to bucket elevators that were not properly cleaned and sealed, to conveyor systems that were overloaded to baghouses of insufficient size and fire protection. A relatively minor investment in a facility’s dust collection system, such as changing to a sufficiently sized collector (i.e. larger CFM, larger baghouse with more dust collector bags) or additional baghouses will prevent the kind of massive capital loss and loss of life seen in these past incidents.

While governmental regulation will not ensure that these tragic incidents are the last of their kind, it is hoped that along with increase corporate awareness and ever-improving dust collection technology, these incidents will become rarer and rarer. Saving not only billions of dollars for companies, but safeguarding millions of workers in these industries.

Dominick DalSanto is an Author & Environmental Technologies Expert, specializing in Dust Collection Systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as Online Marketing Director & Content Manager at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.

Clogged machinery,  exposure to hazardous chemicals, and disruptions in plant processes,  are just a few of the problems that come from using your dust collector hopper for dust storage. 

February 25, 2012 | Baghouse.com News – One of the most common baghouse operation practices that we find when we send a dust collector technical advisor out to various facilities is that many plants unwisely use the hopper on their dust collector for storage of the collected dust. Sometimes this is done unwittingly, as maintenance staff simply overlook emptying the hopper on a regular basis. Other times, this is more or less included (unwisely), into the design by neglecting to install a discharge system, such as a screw conveyor, or slide gate mechanism.

Dust Collector Bags

“You dust collector is NOT designed to store collected material for extended periods of time.”

However, whether this course of action is planned or not, using your dust collector hopper for storage of any collected material for an extended period of time can cause a myriad of problems. Among the various problems that can arise are damage to dust collector bags, increased emissions, increased pressure drop (i.e. increased system airflow resistance), and clogging and damage to dust discharge systems (conveyor systems, slide gates, etc.).

In addition, in some instances involving compounds that may be considered hazardous, storing collected materials in the hopper can lead to extensive fines and prosecution from governmental regulators such as OSHA or the EPA.

A Foundry Runs Afoul of OSHA and The EPA, Lands President and Company in Criminal Court

Recently, a Franklin, New Hampshire metal parts manufacturer and its president pleaded guilty to charges stemming from what OSHA found to be unlawful storage of hazardous compounds. The hazardous or toxic compounds in question were byproducts of the plants manufacturing process, that contained high levels of lead and cadmium. The plant and its president according to court records, knowingly stored the waste with the hazardous levels of lead and cadmium in unapproved containers throughout the plant for longer than the 90 days allowed by law without notifying OSHA and the EPA.

During an inspection of the plant by OSHA in 2009, the plant was found to be in violation of the Resource Conservation and Recovery Act (RCRA), which requires a permit to store hazardous waste on site for longer than 90 days. OSHA notified the EPA of their findings, and then a few months later, the EPA executed a search warrant on the plant found drums of hazardous waste being stored at the plant.

In the end, a federal grand jury indicted Wiehl and Franklin Non-Ferrous Foundry for unlawfully accumulating and storing lead and cadmium hazardous waste at the foundry site since July 2005. Wiehl faces a possible maximum sentence of two years in prison and a maximum fine of $250,000. Under the terms of a plea agreement filed with the court, the United States Attorney’s Office has agreed to recommend that he serve two years of probation, six months of house arrest, and that he publish a public apology. Franklin Non-Ferrous Foundry, Inc is facing a possible maximum fine of $500,000.

Dust collection screw conveyer

Ensure your dust collection system regularly discharges into a dust conveyor system, such as a screw conveyor.

What’s The Lesson? Store Collected Dust Properly! 

While the situation with manufacturer discussed above did not involve storing material in the dust collector, it does demonstrate that the EPA, and OSHA (and other safety organizations) do not take kindly to the storing of chemicals and compounds in inappropriate ways. You dust collector is NOT designed to store collected material for extended periods of time. 

As already mentioned, using your hopper to store dust will lead to a score of problems that adversely affect not only the efficiency of your dust collection system, but your entire plant. These problems drastically increase if the collected dusts contain hazardous materials (lead, mercury, etc.), are an explosion hazard (food products, metal powders, fertilizer, etc.) or are corrosive to machinery. In these instances it is imperative that proper dust transportation, storage and disposal methods are implemented. These include the use of continuous hopper cleaning (such as timed or sense actuated slide gates, pneumatic locks, etc.). It is also vital to regularly check these systems, specially those components most prone to wear and failure such as slide gates, seals, etc.

| Dominick DalSanto is an Author & Environmental Technologies Expert, specializing in Dust Collection Systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as Online Marketing Director & Content Manager at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.

The Chemical Safety Board issued a final report on a series of deadly combustible dust explosions in Tennessee. It highlights dust collection systems as the only way to prevent deadly combustible dust explosions. Recommends OSHA issue new comprehensive dust regulations within one year. 

January 6th, 2012 Baghouse.com News | The Chemical Safety Board has issued its final report regarding a series of deadly industrial dust explosions accidents that occurred at the Hoeganaes powdered metals plant in Gallatin, Tennessee in 2011. The main cause of these three deadly explosions and fires that claimed five lives and injured many others was determined to be negligence regarding combustible dust hazards. The CSB further noted that a main factor in these accidents was the constant neglect of the plant’s dust collection system.

All three of the incidents occurred when large amounts of accumulated highly combustible iron dust where dispersed into the air and then ignited. The plant manufactures various metal powders for industrial use, the most produced of which is iron powder.

Hoeganaes Cumbustible Dust Hazard

Picture of combustible dust accumulations near a bucket elevator that killed 2 workers when the dust was ignited by the motor.

The CSB investigation found that iron dust was present in high enough concentrations in the air to be clearly visible, and had accumulated on nearly all surfaces including elevated ledges, rafters, and other overhead spaces in amounts of 4 inches or greater. In addition the CSB clearly documented through photos and videos how dust handling equipment such as bucket elevators, conveyor belts, etc.  were not adequately sealed, regularly leaking large amounts of dust into the air when in operation, and were not connected to the plant’s dust collection system. Additionally, plant workers told investigators that the dust collection system was regularly out of service due to maintenance.

Three Combustible Dust Incidents At One Plant In Six Months

The CSB investigation begin after the first of the three incidents occurred on January 31st, 2011 when fine iron dust particles coming from a broken bucket elevator were ignited while two maintenance personnel were performing repairs. The airborne particles were ignited by a spark from the bucket elevator’s electrical motor when it engaged. The resulting explosion and fire severely burned both workers, and eventually proved fatal for both men.

Just two months later, while the CSB was still conducting an investigation into the first incident, another flash fire occurred on March 29th when a maintenance worker used a hammer while reconnecting a gas line on the side of one of the plant’s furnaces. When he struck the side of the furnace with the hammer it lofted accumulated iron dust into the air, which then ignited, severely burning him, and causing him to fall from elevated working position further injuring him.  According to CSB officials, “the build up of so much iron dust near a furnace with open flames and hot surfaces was a recipe for disaster. A fire was basically inevitable the moment the dust was dispersed into the air.”

Hoeganaes Cumbustible Dust Hazard

March 29, 2011 Combustible dust fire in Gallatin, Te Hoeganaes powdered metals plant. The second of two serious dust fires/explosions in six months at the plant

Even with two such incidents within two months of each other, Hoeganaes management and its parent company still failed to take action to address the combustible dust safety issues at the Gallatin, Tennessee plant.

This failure proved to be catastrophic as just a few months later on May 27th when the an even deadlier third incident took place. Workers were repairing a corroded furnace pipe containing extremely flammable hydrogen gas caught fire when workers used a forklift to raise a metal floorplate to access the pipe. Workers has assumed the leaking gas was non-flammable nitrogen. After the initial explosion, the leaking gas continued to burn as a continues jet fire. The force of the initial explosion shook loose largeamounts of accumulated iron dust from overhead rafters. As the large plumes of iron dust fell they were ignited by the jet fire causing massive explosions further injuring workers and damaging the plant. One worker stated that so much iron dust was lofted into air, that even with a flashlight he was only able to see two to three feet in front of him as he tried to escape.

Hoeganaes Combustible Dust Explosion

The aftermath of the third Hoeganaes combustible dust explosion in 2011. Notice the dislodged metal floor grating.

Evidence of Danger Present Well Before

All of these incidents were easily preventable. However plant management refused to take appropriate action to improve dust collection at the plant.

Even before the series of incidents, the plant had twice tested its dusts for combustibility. They ever were warned of the potential for a dust explosion after an insurance audit, which cited the potential for a such an accident due to the plant’s poor dust collection system policies, and housekeeping.

In addition to these warnings, the plant had firsthand knowledge of the combustibility hazards present in the plant, when on several occasions flash fires had occurred when workers performed maintenance using welding torches on dust covered conveyor belts. In fact the Gallatin Fire Department Hoeganaes facility in the last 12 years. These included one in June of 1999 where an iron dust fire in the baghouse lead to the hospitalization of one worker for smoke inhalation.

The CSB found that part of the core problem was that the plant, which was built over thirty years ago, was not designed according to good practice guidelines for combustible dust hazards, such as those set forth by the NFPA (National Fire Protection Association). “During its decades of operation, [the plant] was never redesigned to address the serious dust hazards” states CSB investigator Johnnie Banks.

Hoeganaes Cumbustible Dust Hazard - Accumulated Dust

Accumulated combustible iron dust on rafters at the Hoeganaes plant lead to several deaths when a series of dust fires and explosions occurred in 2011.

The plant has numerous flat elevated surfaces that easily accumulate large amounts of dust, and are difficult or impossible to clean with regularity. NFPA 484, which covers combustible metals safety, recommends that “floors elevated platforms, and gratings be designed to prevent dust accumulations and facilitate cleaning.” The same standard also requires that any machinery that emits combustible dust be connected to a dust collection system. Both of these recommendations were not followed by the Hoeganaes plant.

Many have asked how is it that these accidents were allowed to happen, even when plant management had all of these warnings and was in clear violation of best industry standards?

The city of Gallatin requires industrial facilities, including the Hoeganaes plant, to comply with the International Fire Code, which includes a brief chapter on combustible dust standards and references the more detailed NFPA standards. However the code does not require compliance with the more stringent NFPA standards. As a result the plant was not directly in violation of the International Fire Code that it was mandated to follow.

CSB Recommendations Based On Its Investigation

As a result of the CSB investigation, the CSB has proposed several actions be taken to reduce the risk of more combustible dust incidents from occurring elsewhere.

First, the CSB recommended that the International Code Counsel “revise the International Fire Code to mandate compliance with the combustible dust safety standards set forth by the NFPA.”

Secondly, in its 2006 report on the dangers of combustible dust hazards in industry, the CSB recommended that OSHA (Occupational Health and Safety Administration) issue a comprehensive combustible dust safety standard for general industry. As a result in 2007 OSHA instituted a national emphasis program for combustible dust, with the stated goal of eventually issuing a comprehensive combustible dust standard in the near future. In 2009 OSHA announced that it would begin the rule making process for combustible dust hazards. However, in 2011 at the time of these accidents, no standard had yet been proposed, or completed.

As a result, in its final report on the incidents, the CSB recommended that OSHA issue its long awaited combustible dust standards “within one year”, and that the standard include combustible iron and steel powders.  In the meantime, the CSB recommended that plants that manufacture steel and iron powders be included in the national emphasis program. for combustible dust.

 What This Means For Facilities With Combustible Dust Hazards

The continued loss of life due to combustible dust hazards is no longer being ignored by the CSB, OSHA, or other governmental agencies. The only way to prevent the loss of additional lives is for industry to begin following best industry standards as set forth by the NFPA and eventually the comprehensive standard by OSHA.

In the meantime, plant mangers and operators can educate themselves on the dangers of combustible dusts by reviewing educational articles on the subject such as those published here on Baghouse.com (http://www.baghouse.com/2011/01/19/the-potential-for-dust-explosions-in-dust-collection-systems/). They can also seek the assistance of experts in the dust collection industry to identify areas where improvement can be made, and make suggestions of ways to increase dust collection efficiency at their facilities.

For more information about the dangers of combustible dusts, please see the following links:

The CSB video reports on the Hoeganes incidents:

The following LinkedIn groups work specifically to raise awareness of combustible dust hazards, and lobby for comprehensive standards for general industry:

http://www.linkedin.com/groups?gid=1184577&goback=%2Egmp_1184577

http://www.linkedin.com/groupRegistration?gid=2076996&csrfToken=ajax%3A2562522142432018780&goback=%2Eanb_2076996_*2

 

 

About the Author

| Dominick DalSanto is an Author & Environmental Technologies Expert, specializing in Dust Collection Systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as Online Marketing Director & Content Manager at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.

 

Determining which type of dust collector system you need is a specialty of  Baghouse.com dust collection specialists. The three basic types of industrial baghouse dust collection systems are filter bag collectors, cartridge collectors, and cyclone collectors.

Filter bag collectors are produced in a wide variety and have numerous uses. They are very practical for a number of reasons including, but not limited to: overall repair cost is generally low; they efficiently recover heat; it effective against and not affected by gas-dust particulate matter, making it ideal in most situations to utilize.

Cartridge collectors use cartridges, usually cylindrical in shape, with perforated openings that are designed to collect uniquely shaped and sized dusts and other particulate matter. Cartridge collectors are usually compatible with reverse-air cleaning as well as pulse-jet cleaning. They are commonly used for sandblasting, welding fumes, and other fine chemical powders.

Cyclone collectors generally use gravity and an artificial vortex, or cyclone, to separate particles from other gases. Air is pointed and directed through a cylinder and spun creating a centrifugal force which separates and filtrates the air, causing the harmful materials to fall into the collection hoper.

Contact Baghouse.com today to see how we can assist in determining your industrial dust collection system needs.  We are your dust collection experts.

Determining which type of dust collector system you need is a specialty of  Baghouse.com dust collection specialists. The three basic types of industrial baghouse dust collection systems are filter bag collectors, cartridge collectors, and cyclone collectors.

Filter bag collectors are produced in a wide variety and have numerous uses. They are very practical for a number of reasons including, but not limited to: overall repair cost is generally low; they efficiently recover heat; it effective against and not affected by gas-dust particulate matter, making it ideal in most situations to utilize.

Cartridge collectors use cartridges, usually cylindrical in shape, with perforated openings that are designed to collect uniquely shaped and sized dusts and other particulate matter. Cartridge collectors are usually compatible with reverse-air cleaning as well as pulse-jet cleaning. They are commonly used for sandblasting, welding fumes, and other fine chemical powders.

Cyclone collectors generally use gravity and an artificial vortex, or cyclone, to separate particles from other gases. Air is pointed and directed through a cylinder and spun creating a centrifugal force which separates and filtrates the air, causing the harmful materials to fall into the collection hoper.

Contact Baghouse.com today to see how we can assist in determining your industrial dust collection system needs.  We are your dust collection experts.

Industrial baghouse dust collection systems are an air quality purification system for industrial, commercial, or even residential production shops that purify air improving the quality of breathable air while reducing harmful matter. Safe dust collection makes air safer to breathe by removing harmful materials from the environment. Baghouse.com specializes in safe dust collection through capturing particulate matter that would otherwise be released into the environment and possible inhaled, transferring it to collection devices, filtering the air before venting back into the environment, and keeping harmful particulates together for proper disposal.

The purifying of harmful air is most commonly accomplished through use of capture hoods that contain dust and other matter from entering and escaping into the environment. Most safe devices have direct ventilation ports attached directly to them that allow the contaminated air to be easily and efficiently transferred. After harmful particulate air is collected, it is transferred through a ducting system, usually through a controlled vacuum, and is quickly and efficiently deposited into a safe dust collection device. Industrial baghouse safe dust collection systems devices collect the harmful materials, filtering the air, before releasing the air back into the environment while keeping the gathered waste together for easy and safe disposal.

Industrial Baghouse utilizes three different air filtration and dust collection systems: filter bag collectors, cartridge collectors, and cyclone collectors.

Filter bag collectors use filter bags to capture and separate harmful particulates, dusts, and other contaminates. They are very versatile and easily be modified to fit almost any need. When properly maintained they are very durable. They are not suitable for most wet or moist contaminates and do require regular maintenance.

Cartridge collectors are used for very fine dust and other special or uniquely shaped contaminates. Usually cartridges cylindrical shaped and have a cloth or other filtration material covering the cylinder. Cartridge dust collectors can be easy to clean, often being self-cleaning. Cartridge dust collectors are able to vary in size, and larger collection systems might contain numerous cylinders and cartridges.

The advantages of a cyclone collector is that is has low capital cost, it has the capability of operating under high and extreme temperatures, easily and efficiently handles liquid mists or dry materials, usually has low maintenance costs and requirements with no moving parts, and takes up very little space. Disadvantages are that it can be expensive to operate due to creating a pressure drop, has low efficiencies with smaller particles, and cannot process most sticky particulates.

 Next year the Chinese government will update its method of measuring particulate pollution (dust pollution). However these figures will not be released to the public until “an appropriate time” according to the government. 

December 30th, 2011 Baghouse.com News | After years of being derided for its views on air pollution by international and domestic environmentalists, as well as its own people, the Chinese government has conceded to change the way it measures particulate matter pollution (the amount of dust particle pollution in the air) to a stricter standard known as PM 2.5.

The PM 2.5 standard, which is used by most industrialized countries including the U.S. and the E.U., measures airbourne dust particles that are 2.5 microns in size or larger. Currently, China uses the older PM 10 standard that only measures particles larger than 10 microns in size.

Research has shown that the smaller particles are the ones that pose the greatest danger to humans, since their small size allows them to penetrate deep into the lungs.

Particulate matter is generated in many ways, the largest of which are from automobile exhaust and heavy industrial sites.

In the U.S. large industrial sources of PM 2.85 such as coal-fired power plants are required to install and maintain dust collection systems such as baghouses to capture dust pollution before it escapes into the atmosphere.

China, ever the target of environmental criticism, has regularly been attacked by environmental NGOs, as well as foreign governments for allegedly underreporting its air quality situation. The difference is highlighted in its capital of Beijing by the stark contrast between the official government reports, and the regular readings taken by the U.S. embassy which, it then publishes daily on Twitter. The official government air quality reports are consistently orders of magnitude lower than the readings issued by the U.S. embassy. At times the government reports the air pollution as being only “slight” while the U.S. embassy reports readings  of “very hazardous” or “beyond index” on the same day. Needless to say, this is somewhat of a sore spot between the two countries, one that might see improvement once the Chinese government adopts the new measurement standards.

Is Changing To The PM 2.5 Standard The First Step?

While the change to PM 2.5 is encouraging, it alone does not signal a new environmental resolve on behalf of the government. The new measurement system will only be used in large cities, and then the entire country starting in 2015 stated Environment Minister Zhou Shengxian in state owned the People’s Daily. The environmental ministry claims the timeframe is required to prepare for new equipment and personnel.

So while this step is encouraging, and does signal a acknowledgment of the complaints of residents and environmental activists alike, until China adopts stricter air pollution control policies, and pushes for the adoption of pollution control equipment such as dust collection systems in its factories, the amount of particulate pollution in China, no matter how its measured, will continue to adversely affect the lives of all who reside there.

About the Author

| Dominick DalSanto is an Author & Environmental Technologies Expert, specializing in Dust Collection Systems. With nearly a decade of hands-on working experience in the industry, Dominick’s knowledge of the industry goes beyond a mere classroom education. He is currently serving as Online Marketing Director & Content Manager at Baghouse.com. His articles have been published not only on Baghouse.com , but also on other industry related blogs and sites. In his spare time, Dominick writes about travel and life abroad for various travel sites and blogs.