The manufacturing or processing of materials such as wood, plastics, fossil fuels, food, paper, textiles, metals and chemicals can generate dust that is combustible. Combustible dust collected in visible areas, on high surfaces, as well as in the ductwork are a source of industrial fires and explosions. It’s usually when an inspector notices the dust levels on these surfaces is higher than what the code allows that we get called to come out and safely clean it for our customers. Unfortunately, some companies, especially smaller ones, it may seem like a good idea to go ahead and clean it themselves. If they can spare a worker and a shop vac for a day, it’s cheaper, and that should get the job done, right? Wrong! So, then how do you properly clean combustible dust?
First, in order to properly clean combustible dust, we must understand what it is and why it is so dangerous.
What is Combustible Dust
The Occupational Safety and Health Administration (OSHA) defines combustible dust as “a solid material composed of distinct particles or pieces, regardless of size, shape, or chemical composition, which presents a fire or deflagration hazard when suspended in air or some other oxidizing medium over a range of concentrations”.
In other words, combustible dust is any fine material that has the ability to catch fire and explode when mixed with air. 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. Any activity that creates dust should be investigated to see if there is a risk of that dust being combustible. The build-up of even a very small amount of dust can cause serious damage.
Why Combustible Dust Is So Dangerous
For a fire to burn there are three elements needed simultaneously: Fuel, Ignition, and Oxygen – also known as the “Fire Triangle”. But for a combustible dust explosion, two additional elements are needed to form what is known as the “Dust Explosion Pentagon”. These two elements are Confinement and Dispersion.
Dust accumulates over time, and any small fire or explosion that shakes the dust can cause it to ignite. This is dangerous because dust builds up everywhere, such as rafters, roofs, suspended ceilings, ducts, crevices, dust collectors, and other equipment. When the dust is disturbed and under certain circumstances, there is the potential for a serious explosion to occur.
For example, in 2017 A fatal explosion at the Didion Milling in Cambria, WI killed 5 workers and injured 12 others. OSHA officials believe the explosion was preventable and was the result of “Didion’s failures to correct the leakage and accumulation of highly combustible grain dust throughout the facility and to properly maintain equipment to control ignition sources. Didion is facing up to $1,837,861 in fines.
How To Properly Clean Combustible Dust
Knowing how to properly clean combustible dust is important not only for the safety of you and your employees, but in also preventing future dust explosions.
The National Fire Protection Association (NFPA) 654, Chapter 8 - addresses the housekeeping and cleaning procedures. In this chapter it provides details for the frequency that combustible dust needs to be cleaned to reduce risk, what types of methods can safely be used to clean the combustible dust, and what cleaning methods can actually create more of a risk.
Wear the Appropriate Safety Gear
Making sure that wearing safety gear while cleaning combustible dust is an important part of cleaning combustible dust. Using the proper PPE gear will help to ensure the health and safety of the individual who is removing the dust.
- Hard Hat
- Safety Glasses
- N95 Respirator
- Steel Toe Boots
- Hearing Protection
- Gloves
- Safety Harness and Lanyard when working off lifts or scaffolding
- Flame-Resistant Clothing (FRC) when applicable
On occasion, additional respiratory protection and additional PPE may be required.
Use the Right Safety Equipment
Lastly, there are only a few vacuums that are safe to use when cleaning combustible dust. Many dust collection systems just blow the dust around and keep it in the air, trying to have it eventually move into a collection area, but these cause hazards by creating an explosive dust cloud and making the air quality lower. Other dust collection systems do actually suck in and filter the air, but this causes dust to settle in the ductwork leading to the collection system. If the collection area becomes full, the dust can begin blowing backwards out of the vents, making the situation worse than before, and in the case of a fire the dust acts like a fuel, letting the fire travel throughout the building.
- Explosion-proof vacuums
- HEPA-Filtered
- Anti-static / Intrinsically Safe
- Grounded
- Rated for Class I, II, and III environments
- Static dissipative hose with embedded copper grounding wire
- Aluminum brush heads with aluminum extension poles
Using the wrong methods and equipment to clean combustible dust can be catastrophic. From protective clothing to vacuum hoses, every piece of equipment counts when it comes to safety and compliance.
Get the Proper Training and Certification
Having the proper training for cleaning combustible dust is one of the most important parts of cleaning combustible dust. Technicians should be trained in OSHA’s 10- or 30-hour Safety, Aerial Lifts, Confined Spaces, First Aid, CPR, and Combustible Dust Safety and Awareness.
In OSHA’s Combustible Dust National Emphasis Program, two of the most common citations were improper housekeeping, including combustible dust accumulation, and use of compressed air to blow down combustible dust.
This is why a professional cleaning company needs to come in to remove combustible dust. They will have been provided with the proper PPE, OSHA training, and industrial dust removal equipment. However, to keep up with growing demand, our sister company, Safenetix is sharing our vast knowledge of safety practices for combustible dust cleaning and future prevention with facility experts, just like you.
Interested in learning more about what combustible dust is and how to prevent it in the workplace? Click Here to get started with your online learning.
If you have an issue with combustible dust and are unsure about in-house cleaning, Contact Us Here or call 888-845-3952. Hughes Environmental has performed combustible dust cleaning in a wide array of facilities and has dealt with many types of combustible dust. Our technicians that are trained, certified and up-to-date on common best practices. We have an OSHA trainer on staff, and our technicians have been through OSHA 10- or 30-hour training. We also have Council-certified Indoor Environmentalists (CIE) and Council-certified Microbial Remediators (CMR) on staff.
