Is flammable dust always a problem? The basic requirements for a dust explosion to occur is that combustible dusts are suspended in air and are ignited. In practice, for a dust explosion to occur, a number of conditions must be met including: The dust must be combustible and release enough heat when it burns to sustain the fire.
How do I know if my Dust is combustible?
face area to volume ratio greater than that of a 420 μm diameter sphere should also be considered a combustible dust.2 The vast majority of natural and synthetic organic materials, as well as some metals, can form combustible dust. The
Is a liquid that can burn flammable?
Flammable and combustible liquids themselves do not burn. It is the mixture of their vapours and air that burns. Gasoline, with a flashpoint of -40°C (-40°F), is a flammable liquid. Even at temperatures as low as -40°C (-40°F), it gives off enough vapour to form a burnable mixture in air. Phenol is a combustible liquid.
What is the difference between flammable and combustible?
Training might cover:
- Spill response procedures
- Proper use and handling procedures, including storage and transfer of materials
- Suitable ventilation systems
- Area limitations and restrictions, including no-smoking and open-flame rules
- Housekeeping procedures, including equipment maintenance
- Use of fire extinguishers
- Emergency protocols, including an evacuation plan
Is My Dust combustible?
Is My Dust Combustible? It is up to YOU, the manufacturer, to know the composition of the material(s) you process and all applicable laws. MSDS sheets are a good starting point, but most do not address explosivity. NFPA standards 61, 484, 499, 654 and 664 are helpful resources to learn more about your specific dust.
Is regular dust flammable?
Most types of dust are flammable, though it will depend on the type of dust. Due to the extremely high ratio between the surface area of the particles and their total volume (because dust particles are so small), it is often very easy to get dust to burn, even when the material is not otherwise very flammable.
What is a flammable dust?
Combustible dust, also known as explosive dust, is a by-product created from manufacturing processes that involve combustible raw materials. These materials include wood, light metals, several kinds of chemicals, but also agricultural products such as grain, spices, and tobacco.
How much combustible dust is too much?
However, in accordance with the National Fire Protection Association, OSHA developed its Combustible Dust National Emphasis Program, which recommends not letting dust accumulate to more than 1/32 of an inch (about the thickness of a dime or paper clip) over more than five percent of a work area.
Is all dust explosive?
If a concentration of dust is too low, there is not enough of it present to fuel an explosion. If the concentration is too high, there is not enough oxygen to support combustion. While some combustible dusts are easy to guess—wood and paper dust, for example—others aren't, such as aluminum dust.
Is dust a fire risk?
If you don't make an effort to regularly dust your home you could be creating a fire hazard. “Dust can ignite quickly and spread throughout your home if your heaters or electrical sockets cause a spark,” says Dirocco.
How much dust does it take to cause an explosion?
The lower explosive limits of many materials have been measured. They vary from 10 grams per cubic metre to about 500 grams per cubic metre. For most practical purposes it may be assumed that 30 grams per cubic metre is the lower explosive limit for most flammable dusts.
How do you know if dust is combustible?
A value over 0 and below 200 could result in a “weak explosion.” A value between 200 and 300 could result in a “strong explosion.” These substances might include cellulose or wood flour. A value over 300 could see a “very strong explosion.” These materials might include aluminum or magnesium dust.
How do you clean combustible dust?
Some general takeaways for every facility handling combustible dust: Vacuuming is the preferred method of cleaning. When vacuuming is impractical, sweeping or water wash-down are permitted. Blow-down is permitted only when other methods mentioned above already have been used.
How does OSHA define combustible dust?
Combustible dust is defined as a solid material. composed of distinct particles or pieces, regard- less of size, shape, or chemical composition, which presents a fire or deflagration hazard when. suspended in air or some other oxidizing medium.
Is concrete dust flammable?
Certain materials in their pure chemical state will not form combustible dust, including cement, gypsum, limestone, sand and salt. Workers have the right to: Working conditions that do not pose a risk of serious harm.
Is wood dust a combustible dust?
Wood Dust is Combustible and is an Explosion Hazard: Woodworking facilities are inherently prone to fires and explosions mainly due to the accumulation of dust. Preventing and controlling the accumulation of dust through good housekeeping is a key means of controlling fire and explosion hazards.
Is sawdust a combustible dust?
Sawdust can become a combustible dust hazard when conditions are right. Fine sawdust from beetle- infested wood may increase risk for explosions at Washington State sawmills.
What does "fire hazard" mean?
that which can be ignited easily and, when ignited, burns so vigorously or persistently as to create a serious fire hazard.”
Is dust a fire hazard?
When thinking about dust hazards within your facility, the first thought is typically: “Is my dust an explosible hazard?” Even though that is a great question to investigate, another question to ask should be: “Is my dust a fire hazard?” Depending on the answer to this question, your dust may fall into the flammable solids category for identification.
Why is dust a problem?
Household dust can be a problem if left to get too dry, too build-up, and if it settles in the wrong places. A large build-up of dry dust can form clouds if disturbed and can settle around electrical equipment.
What happens if you have enough dust particles?
These particles could be minute, but if there are enough of them you could get a fire or a dust explosion.
What happens if a fire breaks out in a workshop?
So, if a fire were to break out in a workshop, such as from an electrical fault, there is the risk that the dust on the ground will act as an accelerant. Then there is the risk that sparks in the air will ignite dry particles of dust floating around.
How to prevent dust fires?
The best way to prevent dust fires at home is to get into a habit of regular cleaning and to pay attention to where dust settles.
What is the first thing we tend to think of when it comes to dust?
Household dust is the first thing we tend to think of when it comes to dust. But, what about sawdust or the dust created from other industrial processes?
What happens if you have no ventilation?
If you get a high enough concentration of dust in a small space, with no ventilation, you increase the risk of the combustible material igniting. All it takes is enough pure oxygen and an ignition source for a significant fuel-air explosion.
Is it safe to have sawdust in a garage?
Thankfully, most of us don’t have to worry about the dangers of dust explosions unless we have a health and safety role in a mine or factory. You are unlikely to create that much sawdust in a garage and your household dust isn’t that dangerous.
How many workers died in the US from combustible dust?
The U.S. Chemical Safety and Hazard Investigation Board (CSB) identified 281 combustible dust incidents between 1980 and 2005 that led to the deaths of 119 workers, injured 718, and extensively damaged numerous industrial facilities.
How many people died in a 2010 explosion?
The force from such an explosion can cause employee deaths, injuries, and destruction of entire buildings. For example, 3 workers were killed in a 2010 titanium dust explosion in West Virginia, and 14 workers were killed in a 2008 sugar dust explosion in Georgia.
Can a combustible material be explosible?
Any combustible material can burn rapidly when in a finely divided form. If such a dust is suspended in air in the right concentration, under certain conditions, it can become explosible. Even materials that do not burn in larger pieces (such as aluminum or iron), given the proper conditions, can be explosible in dust form.
What is the #1 problem facing industries handling combustible dust?
Question #1: “The #1 problem facing industries handling combustible dust is to recognize and effectively remediate the hazards and ensuing risks posed by the bulk powders being processed. This is as much a social science/management problem as it is a natural science/engineering problem. Safety culture is key to addressing all process safety issues – none more so than dust fires and explosions.”
What is the greatest challenge to companies handling combustible dust in the U.S.?
is the relatively new requirement in NFPA combustible dust standards to conduct a combustible Dust Hazard Assessment (DHA) for every process/equipment/area in which combustible dust is handled or processed. This requirement is a major financial burden for many companies, particularly because of the limited number of personnel with the training and experience to conduct these DHAs. There is a potential for people and organizations with limited experience and understanding of combustible dust hazards and protection options to do these DHAs at a lower cost than more qualified people, producing results of questionable applicability and effectiveness. Another aspect of this issue is the absence of federal regulations clarifying what is required in an effective DHA, and what are the corresponding required minimum protection measures (or risk reduction levels) that companies must implement.”
What are the challenges of dust explosions?
Response: “One of the key challenges in dust explosion research is finding better ways to characterize dust reactivity. While there are great advantages to having a single parameter like KSt to characterize a specific dust under carefully controlled conditions, its widespread use, and lack of viable alternatives, severely limits our ability to quantify the effects of individual parameters, such as dispersion, turbulence generation, and ignition. This impedes our ability to develop models that accurately predict the consequences of dusts explosions over a wider range of initial conditions, as well as our ability to tailor protection methods to specific scenarios and environments that are present in industries.”
What is combustible dust?
Essentially, a combustible dust is any fine material that has the ability to catch fire and explode when mixed with air. Combustible dusts can be from: most solid organic materials (such as sugar, flour, grain, wood, etc. ) many metals, and. some nonmetallic inorganic materials. Some of these materials are not "normally" combustible, ...
What happens to the air in a dust explosion?
In a dust explosion, the deflagration processes happens so rapidly that the heated air and gaseous fire products (such as carbon dioxide) produce extreme air pressure that can blow out walls and destroy structures.
How to get rid of dust?
Do not use brooms or compressed air hoses to clean surfaces. Only use vacuums approved for dust collection. Only use a dust collection / dust extraction system that is designed to eliminate or control combustible dust.
What happens when dust is disturbed?
When the dust is disturbed and under certain circumstances, there is the potential for a serious explosion to occur . The build-up of even a very small amount of dust can cause serious damage.
How are dusts created?
Dusts are created when materials are transported, handled, processed, polished, ground and shaped. Dusts are also created by abrasive blasting, cutting, crushing, mixing, sifting or screening dry materials. The buildup of dried residue from the processing of wet materials can also generate dusts.
What is a deflagration fire?
A deflagration is an "ordinary" fire such as a gas stove, burning wood or paper, and even the burning of gasoline vapour inside the cylinder of an automobile. In a deflagration, a burning substance releases heat, hot gases, and energetic particles or sparks that ignite and spread the fire.
How to reduce dust in a house?
Remove open flames, sparks, friction, heat sources, and other sources of ignition. Select and use intrinsically safe tools or machinery. Put covers around pipes and cables, or embed pipes and cables in the walls, where possible , to reduce surfaces where dust can accumulate.
How to determine if saw dust is dangerous?
The best way to determine the danger level of saw dust is to hire a certified testing facility that will check the material’s fineness, its moisture content — dry wood is more dangerous than a damper product — and other factors, Scott says. “Testing is the most important thing at this point,” he says.
Why is it important to keep dust contained?
Also important is keeping dust contained and preventing buildup on flat surfaces. It’s when the dust goes air borne that danger levels crank up, he says. It was a buildup of dust on unseen flat surfaces that is believed to have caused the secondary explosion in the 2008 Imperial Sugar disaster, Scott says.
What does Scott say about wood dust?
He often speaks to woodworking groups about wood dust dangers and seeks to prepare them for possible regulation. While there might be disagreement about the appropriate level of regulation, there is no debate about the hazards of combustible wood dust, Scott says.
What disasters reinforced what has long been known in the woodworking industry?
These catastrophes reinforced what has long been known in the woodworking industry: Combustible wood dust and a spark spell disaster.
When did OSHA start regulating wood dust?
In 2008, OSHA increased dust inspections and in 2009 announced it would begin development of a federal standard for industrial dust. The agency began writing its first regulation governing wood dust. Years later, that regulation has yet to reach the draft stage.
Why is plastic piping dangerous?
Plastic piping, because it’s prone to static electricity, is another potential danger, he says.
Will the fire protection association change the wood dust standard?
The fire protection association will likely not include major changes to the wood dust standard, Colonna says.
