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Article & Tips


In depth articles and tips about air quality control and safety in the production industry.

Even Small OSHA Fines Can Add Up to a Larger Financial Nuisance…

In the past, Dust In Case has covered stories on some of OSHA’s largest combustible dust fines across many industries, but in other cases, even the smaller ones can add up to a huge nuisance of a financial hit. Take Hunter Panels, LLC, a roofing insulation panel maker headquartered in Portland, ME that has other facilities located across the country as far out as Florida, Texas and Utah. They’re now being faced with the prospect of having to pay $123,000 for a wide variety of OSHA violations ranging from workplace environment deficiencies to not having a safety management program in place. 

Part of the hefty six-figure fine proposal is a $5,000 violation labeled as “Serious” over combustible dust. According to the official OSHA citation, Hunter Panels’ “structural supports, pipes, duct work, roofing and equipment were not kept free of hazardous accumulation of explosive combustible dust.” While just a fraction of OSHA’s proposed levy and perhaps a small chunk of change to a large business, it will always be $5,000 that could have easily been avoiding if the manufacturer had heeded OSHA’s combustible dust safety standards, sought out proper dust control equipment in a certified explosion proof vacuum cleaner or immersion separator and spent the time implementing a plan to remove it from their space. 

The takeaway here is that all combustible dust hazards should be taken seriously, and even the slightest infractions can set off further OSHA scrutiny across your facility that may collectively yield a large fine. 


Grain Elevator Explosion Leads to $180 Million Settlement

On April 27, 2010, the small industrial city of Chester, Illinois made headliness after a combustiblee dust explosion at the ConAgra Foods plant rocked its foundation. Aside from the exteensive destruction and immediate production loss that this catastrophe caused to one of the nation’s leading food manufaacturers, the greatest tragedy of all was the severe injuries suffered by three men working near the grain elevator where the accident occurred. John Jentz, Justin Becker and Robert Schmidt were not actual employees of ConAgra, but were contracted to remove a concrete grain bin from the silo. Jentz suffered burns over three-fourths of his body, requiring various surgeries and skin grafts, while Justin Becker sustained burns to his face, hands and eyes on top of permanent heat-related damage to his lungs that has since forced him to lead a sedentary life. The third man, Robert Schmidt, also received life-threatening burn injuries as well. Now, a federal judge isawarding the three $180 million  paid out by ConAgra and their sub-contractor West Side Salvage Inc. after finding that ConAgra failed to heed advice on proper safety and housekeeping measures which could have otherwise prevented this accident from happening.

According to the lawsuit filed against ConAgra, the victims’ attorneys argued that the food manufacturer failed to clean the bin for nearly two decades, irresponsibly maintained wheat middling pellets within the silo and didn’t take precautions to protect and warn workers about hazardous conditionns despite having this informattion availabble to them. The court was also told that a chemical reaction occurred more than a week before the April 27, 2010 explosion which resulted in detectable rising temperatures within the silo and a strange odor that even residents nearby the southernn Illinois facility could smell. And yet, ConAgraa made no mention of this to Jentz, Becker and Schmidt before they made their way inside the silo to remove the grain bin. 

The $180 million payout arrives on top of various citations, fines and public reprimand levied by OSHA against ConAgra over the incident. What can be done to prevent other food and grain manufacturers from falling into the same pitfalls is not so difficult, as it’s just a matter of educating them on combustible dust hazards and emphasizing the importance of acting on potential risks. The failure to implement a housekeeping program and follow OSHA guidelines is at the core of the ConAgra story, serving as yet another stark reminder as to why explosion-proof vacuum systems are the first step in keeping industrial environments just like this operating safely. With the certified capability to remove these overlooked hazards on the work floor, the simple action of cleaning surrounding dust can ultimately avoid a much larger and serious danger altogether.



Combustible Dust Housekeeping Guide

Ruwac has published an excellent guide titled "Ruwac's Combustible Dust Housekeeping Guide". It contains some incredible insight into the cause of and how to prevent an explosion from combustible dust. We've quoted a portion of the guide below with a link for you to download the full version.


How does dust cause explosions?

You may wonder how dust can cause explosions. For a fire to start there must be three elements - oxygen, heat and fuel. A simple spark in a confined area like a building, room, vessel or process equipment where explosive dust particles are dispersed in sufficient quantity and concentration can lead to rapid combustion. These five factors (oxygen, heat, fuel, dispersion, and confinement) are known as the "Dust Explosion Pentagon". If one element of the…


Training Your Staff

It is critical to develop an employee training program for operating, maintenance and emergency response procedures. Employees involved in operating, maintaining and supervising areas where combustible dust is present must be included in the training and annual refresher courses. Some things to include in your training are…


Download the full guide.

Combustable Dust Explosions

Combustible dusts are fine particles that present an explosion hazard when suspended in air in certain conditions. A dust explosion can be catastrophic and cause employee deaths, injuries, and destruction of entire buildings. In many combustible dust accidents, employers and employees were unaware that a hazard even existed. It is important to determine if your company has this hazard, and if you do, you must take action now to prevent tragic consequences.


How Dust Explosions Occur

In addition to the familiar fire triangle of oxygen, heat and fuel (the dust), dispersion of dust particles in sufficient quantity and concentration can cause rapid combustion known as dellagration. If the event is confined by an enclosure such as a building, room, vessel, or process equipment, the resulting pressure rise may cause an explosion. These five factors (oxygen, heat, fuel, dispersion and confinement) are known as the “Dust Explosion Pentagon”. If one element of the pentagon is missing, an explosion cannot occur.


Catastrophic Secondary Explosions

An initial (primary) explosion in processing equipment or in an area where fugitive dust has accumulated may dislodge more accumulated dust into the air or damage a containment system (such as a duct, vessel, or collector). As a result, if ignited, the additional dust dispersed into the air may cause one or more secondary explosions. These can be far more destructive than a primary explosion due to the increased quantity and concentration of dispersed combustible dust. Many deaths in past accidents, as well as other damage, have been caused by secondary explosions.


Comply With OSHA And Stop A Catastrophic Secondary Explosion

See the video in our "Spark Detection" section for more information.

  • KVA can evaluate your plant for areas that need cleaning or explosion prevention equipment.

  • KVA can provide explosion proof portable vacuum to completely clean your plant of combustible dust. Contact us for a quote.

  • KVA can set up a cleaning program for your plant to be in compliance.

Compressed Air Lines

Process compressed air for your dust collection unit should be clean and dry. Oil/moisture in the compressed line will degrade the life of filter bags on a dust collection unit which cleans with compressed air.


Many filter bag life problems can be traced back to problems with the compressed air system from moisture/oil in the line, the wrong pipe size running to the compressed air tank on the dust collection unit, the wrong compressed air pressure and how often the unit pulses.


The “ON” time setting on the timer board should be set to 1/10 of a second, standard time between pulses should be approximately every 15 seconds. Compressed air pressure should be set between 90 PSI and 110 PSI.


Typically a compressed air line running to the unit should be a minimum of 3/4″, typically larger is better up to 1-1/4″. A good dryer should be installed as part of the air compressor or utilize an in-line dryer with a (-) 40 dew point rating.


A moisture/oil separator with regulator combination is vital to a well operating system. A pressure gauge on the air storage tank on the dust collection unit will advise you if the pressure is correct.

Cold Weather Tune-Up

With winter coming make sure your bag house is working properly. KVA ENGINEERING can inspect your filter for any shortcomings. We also can do leak testing to ensure the filter is returning clean air back into your work place to meet OSHA requirements.


Installation Tips

Be sure to check inlet collar ID and OD. When installing a dust collection system, people become frustrated when they are unable to slip pipe over or insert a coupling into the dust collector inlet. This is because blower and dust collector manufacturers do not adhere to standard dimensions on their inlet collars.


Due diligence on your part will avoid the installer’s nightmare of not being able to make the initial connection when their duct order arrives. A construction drawing might state that the inlet is 12-inches in diameter, but it does not specify whether it is the ID or OD. Even if it does, don’t trust it.

Have your equipment supplier measure both dimensions for you in the factory prior to shipping it. It is also critical that you take time after the equipment arrives to measure these actual circumferences yourself.


In over 75% of the cases when the ID or OD are not matched correctly to the duct-work, it becomes necessary for KVA ENGINEERING to fabricate a simple custom adapter that facilitates the inlet connection.


For the OD, wrap a string around the collar until it meets itself. Then measure the length and divide by 3.14. For the ID, attach masking tape inside the collar until it meets itself. Then straighten it on your bench, measure it and divide it by 3.14.


Your figures will pinpoint the actual diameters that should be relayed to your duct fabricator. In addition, this approach is required when the inlet is out of round caused by damage during transport.

Grain Explosion in Minnesota

The heart of the Midwest’s grain production world was recently rocked by a troubling string of dust explosions within days (in two cases, even minutes) of each other. The even more bizarre detail of these worrisome events is that that all of these accidents occurred in the very same state of Minnesota.

It all began on Monday, August 6th in Tracy, Minnesota around 1:40pm at CHS Inc., an agricultural business owned and operated by farmers, ranchers and co-ops from across the U.S. that specializes in supplying livestock feed, food and food ingredients. According to a report by the The Star Tribune, two men – an employee of CHS Inc. and a non-employee truck driver — were unloading grain using equipment intended for the job when an explosion occurred in one of the facility’s grain elevators. Both men were taken to the hospital where they were treated for burns, and thankfully, no other injuries were reported as a subsequent fire did not break out. As of this time, the extent of the men’s injuries is not yet known while the explosion is currently under investigation.

20 minutes later in Fairmont, MN (about 100 miles southeast of Tracy,) CHS Inc. suffered another damaging grain explosion blow when a fire broke out at their soybean processing plant. reports that a CHS Inc. employee and two firefighters on the scene were dealt minor burned in the mishap. Luckily, the blaze was quickly contained and extinguished by firefighters before it reached the building’s extraction sector, which contains highly combustible hexane gas.

Later that same week around 2pm on Thursday, August 9th, another grain dust elevator explosion took place at the Greenway Co-Op in Kasson, MN, just a little over 100 miles east of Fairmont. spoke with Greenway’s general manager Tim Clemens who says the accident occurred at the top of an 80 ft. leg that lifts corn before it’s loaded into a truck. He also suspects that the explosion may have been caused when a heat source (such as a bearing or moving part) caused the grain dust to ignite. No one was injured in the explosion, as staff followed an in-tact emergency procedure to evacuate and cut power to the facility, minimizing damage to the elevator in the process.

While the extent of damage and injury caused by this rash of grain explosions may not have been as severe as previous incidents throughout history, their frequency and proximity to each other in such short time should raise a red flag to anyone within the industry that has yet to grasp how easygrain dust is to aggravate. Fines and probationary actions from OSHA are likely be levied against CHS Inc. and Greenway Co-Op once investigations are complete, applying unwanted stresses to their business. While credit should be given to both for having emergency response plans in place, the incidents themselves indicate a lack of proper housekeeping inside their facilities that could easily be remedied through explosion proof vacuums. This equipment not only provides superiorgrain dust removal, but does so while keeping work areas clean with certified trust and OSHA compliance. Ultimately, an explosion proof vacuum is an investment that protects both your employees as well as your business’ future.

Texas Metal Dust Fire Justifies Need for Immersion Separators

Three Texas facilities have been cited by OSHA after it was determined combustible metal dust was responsible for causing a flash fire at a work site last summer. The incident, which took place on July 14, 2012, occurred at Watco Mechanical Services in Hockley, TX after employees cutting metal with a torch accidentally set nearby combustible dust aflame during routine blasting procedures at a rail car building. The ensuing fire killed two contracted workers employed by Jordan General and left a third injured according to the OSHA news release. The companies at fault — Watco Mechanical Services, Jordan General Contractors, Inc. and JP Electric — now face penalties collectively totaling $119,840:

  • Watco Mechanical Services, a Kansas-based company, was dealt 14 serious violations, including “failing to adequately control fugitive emissions of combustible dust; keep work areas clean of combustible dust; provide warning signs to alert employees of combustible dust hazards; and keep emergency cylinder respirators fully charged.” Confined space violations were also discovered, with proposed penalties totaling $91,300.

  • Jordan General Contractors was served seven serious violations, with those relating to combustible dust being their failure to provide proper training on the dangers of working with combustible dust and ensuring cutting operations were put on hold while combustible dust was present. Proposed penalties levied by OSHA sit at $20,240.

  • JP Electric, a company contracted to assist with demolition services, was cited with one serious safety violation for failing to prohibit cutting operations in the presence of combustible dust, amounting in a proposed fine of $2,800.

Dust In Case’s coverage of OSHA fines over combustible dust hazards usually can be remedied with certified explosion proof vacuum equipment alongside having a housekeeping program in place to eliminate the presence of combustible dust altogether, but in the instance of a metal dust, an immersion separator is needed to safely contain the material. With an immersion separator, 100% of the intake air is completely submerged in liquids, and the chance of an outside ignition source entering the vacuum is safely ruled out. Had Watco and its contractors been aware of the dangerous atmosphere they were creating by working with and around metal dust, their facility could have potentially avoided this deadly and costly incident altogether. The value of keeping your workers safe, resources in tact and avoiding the future scrutiny of OSHA inspections easily justifies any investment in combustible dust education and the correct explosion proof equipment. Source:

Welding Fumes and Your Health

The American Society of Safety Engineers have published a great article titled “Are Welding Fumes an Occupational Health Risk Factor?“. It contains some incredible insight into the dangers and negative impacts welding fumes can have on your health. We’ve quoted a portion of the article below with a link to the full article.


Welding fume exposure in the workplace is a serious occupational hazard. Employee exposure to welding fumes, specifically to those that contain manganese, has garnered national media attention within the last few years. Thousands of welders have filed lawsuits against welding rod manufacturers, distributors and suppliers alleging that the manganese present in welding fumes causes a host of illnesses, including…

Exposure to welding fumes can cause numerous health problems. When inhaled, welding fumes can enter the lungs, bloodstream, brain nerve cells, spinal cord and other organs and can cause both short- and long-term health effects.


Of the many welders who work in factories or in the construction, ironworks, manufacturing, mining, metallurgy, petrochemical, railroad, shipbuilding or steel industries, most suffer from some sort of respiratory illness or pulmonary infection. In recent years, however, the effects of manganese welding fume exposure on welders’ health have warranted closer study.


Read the full article.

OSHA Combustible Dust Emphasis Program


Special Bulletin: OSHA Combustible Dust Emphasis Program and NFPA

OSHA makes program changes due to a series of dust related explosions in the sugar, petrochemical and metalworking industries.


While this program is not an OSHA standard yet, nor has it been passed into law by Congress, the “OSHA National Combustible Dust Emphasis” program was implemented to reduce the number of fatalities related to workplace explosions. While this is not a standard, non-compliance with the program can and has already resulted in fines and has required process changes in the industries affected by the change. The main attention is focused on the following industries:

  • Metal Dust such as aluminum and Magnesium.

  • Wood Dust

  • Coal and other carbon dusts

  • Plastic dusts and additives

  • Bio-solids

  • Other organic dust such as sugar, flour, paper, soap and dried blood

  • Certain textile materials


But, local inspectors have the leeway to also look at any other type of dust deemed to be a potential explosion hazard. OSHA inspectors are specifically looking for potential ignition sources and the accumulation of dust in the plant which could fuel a secondary, and usually more powerful blast. This could occur if an explosion ever happened in a dust collector or plant equipment, causing the dust accumulations on rafters, floors and other flat surfaces to shake loose and become airborne in a concentration that, if ignited would cause the secondary explosion. To that end, housekeeping becomes an area of vital importance.


OSHA inspectors are looking for dust accumulations that are at least 1/32″ thick and over a surface area exceeding 5% of floor area of any given room or plant. If the inspector deems it necessary, samples of dust must be sent to a testing laboratory to gauge their level of explosiveness. This is site and dust specific and generally accepted values for the dust are no longer considered to be valid. If the dust is considered to be a hazard, any dust collector located in the building or outside the building must now comply with all applicable NFPA standards.


In addition, the program emphasizes the need for prevention of dust clouds forming off of equipment such as grinders, mixers or other dust producing operations. Thus, the need for properly equipped dust collection is further mandated within the program.

Spark Detection


Nine years after Corbin explosion, still no dust regulations

On Feb. 20, 2003, powerful dust explosions tore through the CTA Acoustics plant in Corbin, where fiberglass insulation was manufactured for the automotive industry. The loss of seven lives and scores of injuries made the accident one of the state’s deadliest. U.S. Chemical Safety Board investigators found that the explosion was fueled by resin dust which accumulated in a production area and that was likely ignited by flames from a malfunctioning oven. The resin involved was a phenolic binder used in producing fiberglass mats.


Read more:


Spiral pipe is designed to be easy to install. All pipe ends are female, and all fitting ends are male, allowing pipe and fittings to easily slip together. There are several methods of joining Spiral pipe and fittings, depending on your application and your applications requirements.

  • Slip Joints: Slip joints are the simplest method of joining Spiral pipe.

  • Fitting-to-fitting joints (male to male) require a separate coupling, C-1-F: or a short, hand cut section of Spiral pipe can be used as a coupling for quick, in-the-field connections.

  • Pipe-to-pipe joints (female to female) also require a separate C-1 coupling.

  • Pipe-to-fitting joints slip together without the need of a separate coupling.

Slip joints are fastened with screws or pop-rivets, and duct sealant or sealant tape when additional air tightness is required. (The screws or rivets hold the pipe in place as the sealant cures.) The standard recommendation is for screws or pop-rivets to be used at a maximum of 15″ intervals with no fewer than three screws or pop-rivets per joint. We recommend a maximum interval of 6″.

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