By now, if you deal with combustible dust in your facility, you have probably heard about NFPA 652, the new Standard on the Fundamentals of Combustible Dust. According to this new standard, your company must have completed a Dust Hazard Analysis by October 2018. OSHA inspectors making overall safety checks can ask for a company to present its DHA and may fine any company that hasn’t conducted one if the dust is a safety hazard.
How do you know if NFPA 652 applies to you and if you need to conduct a dust hazard analysis?
This standard applies to both new installations and existing facilities, so if your process produces dust of any type, it might apply to you. The first step is to conduct safety testing on your dust or particulate if you haven’t already. Because NFPA 652 is a combustible dust standard, the first step is to have a dust test performed. This will give you key information about whether your dust is combustible, how dangerous it is, and what steps you may have to take to address it.
A dust hazard analysis is a review process that looks at each part of the facility’s processes and evaluates any fire, deflagration, or explosion hazards that are present anywhere in the facility as the result of combustible dust. By this standard, it is not good enough to be able to show that you had your dust tested and that you have a dust collection system in place. The entire hazard analysis must be documented. This includes checking for the following hazards and documenting them completely:
Is the dust in this process or area combustible?
Is there dust accumulation in any part of the area?
At any point in this process, is the dust airborne or in a cloud (where it is easier to ignite)?
Are there any ignition sources that could ignite the dust?
Is there enough dust present during the process to allow a deflagration?
Once all these factors have been assessed, the dust hazard analysis needs to answer some very important questions about what’s being done currently and what needs to change in managing the hazards.
What hazard management is in place right now to deal with the combustible dust hazard in each area or process?
Does the current hazard management address all the issues that the hazard analysis uncovered?
If current hazard management isn’t enough or doesn’t cover everything, what steps need to be taken to improve it?
Keep in mind that this is necessary for each area or process in your facility, even if you have one centrally located dust collection system. For example, if your metalworking facility has plasma cutting, welding, and grinding or other fabrication processes, the DHA has to assess the hazards for each one. The weld fumes present a different type of risk than the dust from grinding, for example, and some processes produce a fine airborne fume instead of a heavy accumulating dust.
It’s possible that your DHA will find that you have your combustible dust and fume hazards under good control. If that’s the case, conducting the DHA will give you a full hazard report that meets NFPA 652 standards and that you can present to an OSHA inspector.
If your DHA identifies hazards that still need to be addressed, it’s still very important that you’ve done your work, documented all the combustible dust hazards, and are taking steps to fix problems. Contacting a dust and fume collection professional like Imperial Systems will help you identify your options. We can help you make sure that every area of your facility passes the dust hazard analysis.
NFPA 652 is the organization’s new attempt to prevent combustible dust damage, injury, and death in the workplace. A dust hazard analysis may take time and require good documentation, but it might help you catch a potentially dangerous problem. Take the time to conduct a dust hazard analysis, or have professionals come in and assist you. Address problems if you find them, and you’ll have a safer and healthier workplace.
Download our Dust Testing Sheet and call our team to have your dust tested for a KST value.
Creative Pultrusions manufactures fiber reinforced plastic for the infrastructure, marine, and other corrosion-resistant markets. Fiber reinforced plastic is durable, resistant to corrosion and damage over time, and makes an excellent support material for many projects.
The company not only manufactures large pieces of fiber reinforced plastic, but they also do many kinds of secondary work, including drilling, sanding, cutting, and CNC machining, which produce large amounts of dust. Testing identified this dust as weakly combustible.
When Creative Pultrusions ran into OSHA’s increased interest in combustible dust management, they considered upgrading their current system of vacuums and slide gates, but discovered that a new system from Imperial Systems was just as cost-effective as trying to rebuilt the old one.
Working with Creative Pultrusions, Imperial Systems was able to design for them a turnkey CMAXX Dust & Fume Collection system that met all of their needs. Once main concerns was air flow to the very large CNC machines that the company uses on large pieces of material. With specially engineered and placed fans, the CNC machines got all the airflow they needed, and the rest of the facility got the dust protection that it needed.
In a large facility where there are so many different stations for grinding, sanding, drilling, and machining, there are many locations for dust to be produced. Imperial Systems was able to design a system where dust was safely captured at all of these check points and removed from the work area.
One important aspect of the system designed by Imperial Systems was the complete fire and explosion prevention equipment that helped them meet NFPA standards on combustible dust. The system even allowed them to increase safety and dust control in areas that hadn’t had sufficient dust collection before the new system.
The company feels safer from combustible dust risks, and they feel confident that they are meeting all NFPA standards and they are prepared for any of OSHA’s expectations. Because Imperial Systems products are built to last, the company remains just as happy with their system today as they were the day it was installed, and confident that they made the right decision in choosing to go with Imperial Systems.
At the time, as a company still building our reputation in the dust collection field, the opportunity to work with a local Pennsylvania company to showcase our skills was a great chance to prove everything we are capable of, and the system we designed was, and continues to be, a showcase of the quality of work that we provide to our customers every day.
We continue to provide as-needed maintenance and support to Creative Pultrusions as their needs grow and adapt. Customer service is a hallmark of Imperial Systems and our field service teams are second to none in their level of expertise and skills.
If you are looking for a new dust collection system, please take a few minutes to watch the video and hear the people from Creative Pultrusions describe in their own words how this system has changed their facility and provided them with exactly what they were looking for.
With the exploding popularity of 3D printing, it’s inevitable that combustible dust hazards would become part of the process. After all, 3D printing uses materials from plastics and nylon to aluminum and titanium. Almost all of them are combustible and can form explosive airborne dust around the work area.
3D printing is also called additive manufacturing, and it works by fusing layers and layers of extremely fine dust to create the final shape. When using metals, plastics, or ceramics, the layers are often fused by a laser that has the precision to carry out computer-guided designs.
The term “additive manufacturing” is most often found in applications like metalworking, where it is used as an opposite of manufacturing that involves removal of material, like cutting or grinding. 3D printing is a much broader term and can apply to a wide variety of processes.
If the combination of combustible dusts and high-powered ignition sources doesn’t sound like an explosion hazard, consider the fact that this is still a new technology, and many dust collection systems on the market aren’t equipped to handle this kind of hazard. OSHA has already cited at least one company for an explosion that occurred when combustible aluminum and titanium metal powers from their 3D printing process ignited, causing serious injuries.
Besides the risks of a combustible dust explosion, the extremely fine powders needed for 3D printing or additive manufacturing are often hazardous to human health. In other blog posts we’ve discussed the health risks of inhaling these particles, which can be as fine as welding fume dust. With the materials being fused by lasers or other high-heat techniques, harmful particulates are being released into the air along with the dust from the manufacturing process.
These harmful particles can include plastic particles, known toxins like hexavalent chromium, or even byproducts of high-tech aircraft alloys like beryllium. Many of them are health hazards and almost all of them are explosive if the conditions are right. Additive manufacturing or 3D printing often creates perfect conditions for a combustible dust explosion.
How do you mitigate the risk of combustible dust in your 3D printing operation? Proper dust collection will remove all excess dusk from the work area, preventing an explosive situation from occurring. With the CMAXX dust and fume collector, the most efficient filtration and best explosion protection are on your side to make sure your 3D printing areas, expensive pieces of equipment, and workers all stay safe.
Imperial Systems is ahead of the game in designing custom solutions for 3D printing and additive manufacturing applications. If you’re looking for a solution for the combustible dust problem that your application creates, contact the company that’s already designing systems to handle exactly these kinds of problems.
With the best design and quality on the market along with unbeatable fire and explosion protection options, the Imperial Systems CMAXX is the solution 3D printers need to keep their process efficient and safe. High efficiency filters allow for the capture and reuse of expensive powders and keep your work area clean of combustible dust. They also keep your air clear of dangerous byproducts and toxic substances your process might use or produce.
Jeremiah Wann, Imperial Systems, discusses the benefits of Spot Filters when dealing with dust at cement plants.
SPOT FILTERS: ALL-PURPOSE CEMENT DUST SOLUTIONS
There are many opportunities when working with cement for dust to start accumulating. Anywhere that the material is moved around, dust is produced. With companies facing new and stricter OSHA silica exposure laws, there is a tremendous need for filters in cement applications. Respirators may not be able to handle the high levels of dust produced, and even if they can, they are uncomfortable and often not used correctly.
OSHA’s hierarchy of hazard management considers the first line of defense as eliminating the hazard. Since it’s probably impossible for you to eliminate all the processes in your facility that produce dust, it makes sense to move to the next step, which is to use engineering controls to manage the hazard. A dust collector is an engineering control because it manages the hazard without the employees needing to actively do anything (like wear PPE) to be protected.
BAGHOUSE VS. CARTRIDGE COLLECTOR
While baghouses have dominated the cement industry in the past, they have many disadvantages. A major one is that very high airflow needs to be maintained to move dust-laden air from the various points of capture to the baghouse, requiring high energy usage and large fans. Also, baghouses often have a huge number of bags, which are very difficult and messy to change. A confined space procedure may be required to get into the air plenum where the filters are accessed. The bags often have to be pulled onto metal cages and there are a variety of complicated mechanisms for attaching them to the tube sheet.
Cartridge collectors are appropriate for almost all types of fine dust, as long as it is dry, and they are more efficient and much easier to change than bags in a baghouse. Cartridge filters are pleated, which allows them to have a much higher surface area than a bag and pack a lot more media into a smaller space. The ease of changing filters and overall maintenance is often a major factor in choosing a cartridge collector over a baghouse. Baghouses may still be preferred for certain applications; a systems engineer can help determine which will work best. High temperature applications, for example, often require a baghouse because the bag material can handle extreme temperatures better. Systems engineers are experts in system design and should always be consulted on a dust collection project.
Many applications, particularly those handling large amounts of bulk solids, have had excellent results with cartridge collectors. Grain and silica industries are two examples of applications where cartridge collectors are often in use. Especially where silica dust is involved, cartridge collectors are becoming increasingly popular because of the extremely high efficiency of the filter media, which helps companies make sure they are meeting OSHA’s new silica dust regulations.
Some companies have questioned whether cartridge filters are durable enough to handle tough applications like silica or cement dust. The answer is that yes, with a properly designed system they can definitely handle this material. Options such as overbags can help protect the filters if the dust stream contains some larger particles in addition to smaller ones. A cartridge collector will also have baffles that cause the air to slow down and larger material to drop out of the air stream before it reaches the filters, protecting them from damage.
SPOT FILTERS
Another issue may pop up with a central vacuum system. Whether it uses bags or cartridges, there may be very long runs of ductwork to access all of the points of dust capture. It may not be practical to run duct all the way down a very long conveyor, for example, or to a machine that’s a long way from the collector. You may even need dust collection on a mobile piece of equipment like a cement dust transport truck that moves material around the site. For all of these situations, spot filters are a great option to consider.
A spot filter is a small cartridge collector that is placed directly at the location where dust is being produced. Examples of good locations for spot filters include:
• Drying areas
• Conveyor belts
• Transfer points
• Dump pits
• Roller mills
• Blenders and mixers
• Bucket elevators
• Hammer mills
• Transport trucks
• Vents and openings in storage areas
• Material loading and unloading
Spot filters usually have two or four cartridges. Because of the pleated material, cartridge filters are perfect for applications where the collector needs to be small and compact. They are also self-contained, which means they do not need any ductwork run to them. They have their own fan and run independently, so you can put one a long way from your central dust collection system, or use them if you don’t have a central dust collection system. Spot filters sit directly at the point where the dust is generated, allowing them to capture the maximum amount of dust and prevent any of it from getting out into the air of your facility or exposing your workers to silica-containing dust.
An advantage of spot filters is also that they are very easy to maintain. In a well-designed collector, cartridges slide out easily on rails and new ones slide back in. This only applies to vertical collectors where the cartridges hang from a tube sheet at the top of the collector; horizontal collectors where the filters are inserted horizontally on a supporting yoke are much more difficult to change. The filters do not need to be cleaned; they clean themselves with compressed air according to their scheduled settings and maintain efficiency by pulsing excess dust off the filter surfaces.
Spot filters are perfect for those areas in a facility where fugitive dust escapes into the environment. This dust can accumulate around the area and cause a health and safety hazard. Certain pieces of equipment may be inconvenient or nearly impossible to reach with ductwork or attach to a central collection system. For these, spot filters can capture that fugitive dust before it gets loose to build up around the area.
A patented version of a spot cartridge collector is specifically designed to be mounted on trucks transporting and unloading bulk dust. Specifically designed for sand on hydraulic fracturing sites, these collectors are able to be mounted directly on a truck that’s used to load and unload cement dust. This is is a complete plug‑and-play system. It can be mounted on sand transport trucks, at the points where material is being moved onto and off of transport belts, and over mixers and other equipment. The fans and airlocks are operated with hydraulics powered by the vehicle, and the compressed air is powered by a generator.
OSHA SILICA REGULATIONS
Because of the silica content of cement dust, new OSHA silica laws taking effect in 2018 will impact health and safety in the cement industry. These new laws strongly endorse engineering controls such as dust collection systems to prevent exposure to silica dust in the air.
In many places, we’ve seen a central baghouse removing dust from several main points of dust production. However, a lot of these places also have a number of other sites where fugitive dust is escaping and contaminating the area, accumulating around the facility. This dust can be easily stirred up and inhaled.
Health risks of inhaling silica dust include silicosis, a chronic lung disease where inhaled silica dust, such as the kind that is a component of cement, damages and scars the small air sacs of the lungs. This results in difficulty breathing and getting enough oxygen to the rest of the body. Exposure can also cause an acute form of silicosis where the damage causes the lungs to swell and fill with fluid. This type of silicosis is uncommon but very dangerous.
Chronic silicosis is very common among people exposed to silica dust. The scarring can progress to a condition called progressive massive fibrosis, where the lungs become stiff and full of scar tissue. When the disease is severe, people may need oxygen support to be able to breathe. Silicosis can cause death.
The health risks of silica include other deadly conditions. Silica is a known carcinogen, meaning it causes lung cancer. It also makes you more likely to get lung diseases like emphysema, tuberculosis or bronchitis. Because the cement industry has been targeted as one in which the dust includes silica, OSHA is likely to be very vigilant about dust management in cement handling applications.
CONCLUSION
Spot filters may be exactly the solution you are looking for if you have equipment such as conveyor transfer points, mixers, elevators, or other places where dust has a tendency to escape. If you don’t have a current dust collection system, or if it’s not practical to attach these pieces of equipment to the current system, a spot filter can be a very efficient solution. It sits directly on the area where dust is produced, captures it before there is any opportunity for it to get out into the air in the facility, and contains it safely.
Sometimes it’s necessary to cut or weld, or hot work in the vicinity of your dust collector. However, this can be extremely dangerous if your dust is explosive. A dust collector, after all, is an accumulation of dust. If that material is combustible, careless hot work could lead to a catastrophic explosion.
“Hot work” is defined by OSHA as “welding, brazing, cutting, soldering, thawing pipes, using heat guns, torch applied roofing and chipping operations, or the use of spark-producing power tools, such as drilling or grinding”. Most of us would think twice about welding or cutting in near a dust collector or any other combustible dust. But some tools, even ones that shouldn’t produce sparks, may have faulty wiring. This can lead to a fire or explosion.
Hot Work Procedures
No hot work should be done near the dust collector without the correct procedures (see NFPA 51B). This NFPA standard specifically defines the procedures for conducting this type of work anywhere that it might cause an explosion.
Hot work near or on a dust collector might include repairs or adding/removing a piece of equipment or ductwork. It may include any number of other projects. Before doing this kind of work around the dust collector, you must have a hot work procedure IN WRITING:
Shall be in writing and available to anyone conducting hot work in the area
It must require an inspection of the work area before the work starts
Must have a permit signed to show that all phases of the work have been inspected and approved
The program should assess safety equipment in the area. On a dust collector that might include a spark arrestor, spark detector, fire suppression or sprinkler system, abort gate, explosion venting, or other types of fire and explosion safety devices.
Hot work may require completely blocking the ductwork to the dust collector, or if the work is on or close to the collector, may require removing the filters, emptying or removing the hoppers, and thoroughly cleaning the entire dirty air side of the dust collector. a strong g recommendation is that a fire suppression system is in place before hot work begins. This will suppress any fire that might start. Further, remove as much of the dust as possible if it is explosively combustible.
Permits Ensure Safety
NFPA 51B specifies that the company safety specialist will issue a permit for work to proceed once achieving an inspection and determination of safety for hot work. It’s the job of this designated safety specialist to inspect the area of hazards. The specialist ensures the removal of all combustible dust. They confirm the isolation of all sparks and heat and establish safety procedures in the event of a fire.
No one should be allowed to perform ANY type of hot work, including the use of spark-producing power tools, in the vicinity of the dust collector without a permit. However, it happens all the time and puts lives at risk if the dust is combustible. Take the time to assess this hazard in your own workplace. If the hazard exists, your safety professional should set up hot work procedures to make sure no one puts themselves or the facility at risk.
Jeremiah Wann, Imperial Systems, discusses the benefits of Spot Filters when dealing with dust at cement plants.
