by Imperial Systems | Jul 7, 2016 | Uncategorized
What Makes Good Chromium Go Bad? How This Anti-Corrosion Wonder Metal Can Turn Into an Occupational Health Disaster
Chromium is an amazing metal. Polish to a brilliant shine and will keep that shine without tarnishing or corroding. When allowed with other metals, it makes them harder and more corrosion-resistant. Also, electroplating with chromium gives a durable, high-polish coating. However, chromium can produce toxic metal dust.
Chromium didn’t get its name by being shiny, though. “Chroma” is the Greek word for “color.” Many chromium compounds come in bright, beautiful colors including purple, yellow, and green. For many years, chrome yellow was used to create the familiar yellow school bus. The military uses chrome pigments that reflect infrared rays to conceal vehicles. Some treated wood and tanned leather use chromium salts.
What turns this incredibly useful item into a toxic metal dust health hazard?
Metals exist in a variety of oxidation states, depending on the compounds they are part of. Metals are good at sharing electrons, so chromium, like many other metals, can exist in several different oxidation states. Hexavalent chromium or chromium (VI) is a chromium compound at the +6 oxidation state. In this form, it mimics other essential elements and tricks cells into taking it in. Depending on the site of exposure, the results can be skin damage, stomach, and intestinal injury, lung damage, and eventually lung and kidney cancer.
Many dyes, pigments, and primers contain hexavalent chromium in its direct form. Most exposure, though, occurs when stainless steel or other metals alloyed or coated with chromium are heated by welding, grinding, or cutting. The heat involved in these processes causes previously stable and harmless chromium to oxidize to its dangerous hexavalent form.
Welding fumes, grinding or metalworking dust, and fumes from plasma or laser cutting tables can all contain this form of chromium as a toxic metal dust. So can dust or smoke from treated wood, dust left over from leather tanning and residues from electroplating with chrome or from heat-treating materials with a chromium anti-corrosion coating.
Awareness Is the Key to Prevention
Remember Erin Brockovich? She made a name for herself fighting a facility in southern California. They had been using hexavalent chromium in their systems as a corrosion prevention agent and then allowed it to contaminate the groundwater. She has since gone on to participate in several other high-profile lawsuits involving the contamination of groundwater with hexavalent chromium in Missouri and Texas.
OSHA and environmental groups including the EPA closely monitor all forms of toxic metal dust including hexavalent chromium. If your facility’s dust collection equipment isn’t up to the job of handling this byproduct, your workers are at risk of health problems. Which means you could be at risk of fines. Many companies don’t know that their processes are producing hexavalent chromium. This dangerous version of a common and useful metal is found in more types of dust, smoke, and fumes than you may realize.
Check out our infographic on hexavalent chromium!
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by Imperial Systems | Jul 1, 2016 | Uncategorized
The Mechanics of Deflagration: Dust Testing Research
Some dusts are more dangerous than others. The organizations that set standards for combustible dust management, like OSHA and the National Fire Protection Association, run dust testing on many types of dust to determine how dangerous they are and what conditions make them explode.
In many cases, these formal tests replicate what common sense would already tell you. Combustion chambers are often used to measure the amount of pressure that’s produced when a measured amount of a dust is ignited. They are used to measure the minimum concentration of the dust that’s needed to start a deflagration. This is an important number, because even if you don’t normally produce enough dust to reach the concentration that could ignite, a heavy day of fabrication or dust dislodged from overhead surfaces could raise that into the danger zone.
Methods of Dust Testing
A combustion chamber is also used to test another key component of an explosion: the amount of oxygen needed to fuel it. Fire requires oxygen, but depending on how flammable a material is, it may burn even in an environment with low oxygen.
A spark igniter creates sparks to test the minimum amount of energy needed ignite a deflagration. Materials that are very easily ignited by even a small spark are a hazard in any situation where there is static discharge, even in the absence of any heat or flame.
A furnace is used to test how hot a material has to get before it will spontaneously ignite without a direct heat source. A cloud of dust may not burn even in very, very hot air unless there is a spark or flame to ignite it. If the dust ignites in the furnace, it means that temperature control is a key factor in handling this dust safely.
Some dust testing use a hot surface to test whether dust will ignite when a surface with a layer of dust on it is heated. Again, some types of dust may not ignite even when exposed to very high temperatures unless there is a spark or flame, but some types of dust may ignite from being in contact with a hot surface, and this type of dust is dangerous anywhere that it could come into contact with hot materials.
Conclusion
These factors together are used to calculate a deflagration index, which is an overall rating of how likely that type of dust will produce a deflagration. This index is used to group dusts into explosion classes: Class 0 in non-explosive (silica), Class 1 is weakly explosive (charcoal, zinc, many food products), Class 2 is strongly explosive (wood flour, many plastics) and Class 3 is extremely explosive (aluminum and magnesium dusts, some plastics and other chemicals)
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by Imperial Systems | Jun 29, 2016 | Uncategorized
OSHA scientists aren’t the only ones who know how metal dust hazards can damage the human body. 
In 1954, the famous science fiction author Isaac Asimov wrote the novella Sucker Bait, the story of an expedition sent to investigate the deaths of an entire colony on an alien planet. Even though the planet appeared to be totally safe for human life and none of the local plants or animals seemed dangerous, the entire colony had died within two years of their arrival.
The reason this seemingly perfect planet was uninhabitable: beryllium.
Isaac Asimov knew that high levels of beryllium in the soil and air was the perfect way to gradually poison the colony without the residents even realizing what was harming them. Inhaling beryllium dust causes an often fatal lung disease called berylliosis. The colony was slowly destroyed by toxic metal dust hazards they didn’t know was killing them.
Beryllium doesn’t just exist in the domain of science fiction, though. Beryllium is often alloyed with iron and aluminum, which makes these metals stronger and lighter. Beryllium is frequently used in aerospace applications because its alloys are lightweight and can tolerate high heat. Beryllium alloys with copper and nickel are used to make tools that don’t spark and can be used near flammable substances.
OSHA regulates beryllium exposure due to the potential for lung disease and its status as a cancer-causing agent (https://www.osha.gov/SLTC/beryllium/). If your dust collection system is protecting your employees from other metal dust and fumes, it should protect them from this hazard as well. Just one more reason why a properly functioning dust collector with filters capable of capturing very fine particulate are a key part of keeping workers healthy.
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by Imperial Systems | Jun 27, 2016 | Uncategorized
You may have heard about explosive dust before. You’ve read news about a manufacturing facilities that suffered a catastrophe due to combustible dust ignition. Did you ever wonder how it happens? How a small collection of dust particles can explode with such tremendous power and scale? We at Imperial Systems, Inc pose an even greater question: Is your workplace and employees safe from this risk?
Read this industry alert that was written by the North Carolina Department of Labor Safety and Health Division about the Dangers of Combustible Dust. It is an excellent learning resource that clearly defines the dangerous and sometimes fatal results of instantaneous dust explosions.
Imperial’s CMAXX dust collector deflagration testing
Over the years Imperial Systems has posted many blogs about explosive dust dangers. We have the knowledge, the experience and the right equipment to prevent explosive dust ignition in your facility. Need more information? Give one of our professional team members a call today at 800-918-3013.
To learn even more, check out our other articles on combustible dust dangers. Knowledge is the real power in prevention.
Eliminating Fumes And Dust From Your Metalworking Facility
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by Imperial Systems | Jun 21, 2016 | Uncategorized
Welding Fumes Meet “CSI”: Why Scientists Are Collecting Welders’ Toenails
A group of researchers interested in exposure to metals in welding fumes come to your workplace to collect samples. You might think they’d be there to test the air quality or to take samples of fumes or dust. However, these researchers didn’t come to do any of those things. The only equipment they bring with them: paper envelopes and toenail clippers.
That’s right… these researchers are here for your toenails.
That’s how researchers from the Harvard School of Public Health (Grashow et al, 2014) studied the long-term exposure to toxic metals in weld fumes in a group of welders in Massachusetts. The welders provided several toenail samples over a period of time for analysis of the clippings.
Some forensics television shows have investigators acquire a hair sample and test it for poison. This works because many things that get into our bloodstream, including metals, deposit into our hair and fingernails as they grow. The researchers chose toenails because they grow more slowly and give a record that covers a longer period of exposure.
So what did they find?
Even among workers who wore respirators, researchers were able to detect lead, manganese, cadmium, nickel, and arsenic. Lead is a well-known health hazard, and you probably know that arsenic isn’t a good thing either. Long-term exposure to manganese often leads to central nervous system problems that can mimic Parkinson’s disease. Cadmium can cause cancer, and nickel can cause skin problems and lung irritation.
Respirators are a key part of controlling exposure to welding fumes. However, exposure to enough of these metals would reveal their presence in their toenails. While it wasn’t within the scope of this research study to determine exactly how workers were exposed, one possibility is that respirators may be worn while welding, but not while doing other work around the shop in places where dust from cutting and welding may have accumulated.
A dust collection system that removes welding fumes and dust from the air completely will prevent toxic metal particles from accumulating in your work areas. Respirators may prevent inhalation during welding, but if the weld fumes aren’t being removed from the air, workers can still be exposed to it. A system that keeps the air clean for your entire facility doesn’t just protect workers while they’re wearing respirators. It protects all of your workers, all of the time.
Grashow, R. et al (2014). Toenail metal concentration as a biomarker of occupational welding fume exposure. Journal of Occupational and Environmental Hygiene, 11, 397-405.
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by Imperial Systems | Jun 14, 2016 | Uncategorized
Dust collection management is one of the main investments that those in the timber industry must face in the near future. In fact, Timber Processing Magazine (www.timberprocessing.com), which conducts research on industry production, supply, and investments, notes that many facilities will need to plan for additional equipment needs above and beyond those they have already planned for.
Areas where facilities may need to plan for investments include:
Complete BRF System Installation
- Loading equipment
- Drying kilns
- Planer mill sorting and packaging
- Forklifts
- Conveyors
- Dust control
Because of the highly combustible nature of wood production dust and OSHA’s increasingly strict regulations on combustible dust collection management, dust collection equipment is one of several investments that companies in this industry may need to consider.
Modernization of equipment is often essential to streamline production and materials handling. According to the surveys conducted by Timber Processing Magazine, almost 75% of facilities rated their return on investments in 2015 as “good” or “excellent.”
Investing in Reliability, Safety
When considering where to put that investment, dust control equipment should definitely be top on the list. Processing more product creates more dust, and nothing can shut your production down faster than a malfunctioning dust collection system or, worse, a fire.
Even if your current dust collection system is handling your dust adequately, equipment such as explosion isolation valves, spark arrestors, and backdraft dampers can be a valuable investment in fire and explosion prevention. Wood processing dust has unique demands on dust collection and fire suppression systems, and an experienced systems engineer should be consulted to ensure equipment is optimized for your particular application.
Good news for the timber industry is also good news for manufacturers who produce dust collection management equipment for this industry. This recent report makes it clear that this industry is alive and well, and that companies are likely to see long-term benefits from investments they make in new equipment.
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