Combustible Wood Dust Explosions | WorkSafeBC

Learn how to reduce the hazards associated with combustible wood dust in the workplace.

Combustible wood dust refers to the fine, dry wood particles that are a by-product of milling wood. This animated video explains why it's a hazard in sawmills and wood shops, and how it only takes a spark to create a fire or explosion that can cause catastrophic injuries, loss of life, and destruction of buildings. Fortunately, these incidents are preventable.

This educational video is a useful health and safety training tool to help employers and workers identify, manage, and control risks associated with combustible wood dust. It’s designed to be watched in conjunction with training in combustible wood dust hazard recognition and mitigation controls.

Timestamps:
0:00 Intro
0:49 What is combustible wood dust?
1:13 What conditions can make fine wood dust explosive?
1:59 Where can wood dust settle?
2:19 How much wood dust is needed to create a fireball?
2:40 What is deflagration?
3:42 A potentially enormous destructive power
4:05 Where can a combustible wood dust explosion occur?
4:18 How to prevent combustible wood dust explosions

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[jizzle]

This can happen with nearly any fine dust. Even powdered coffee creamer is flamable..
Also happens to grain silos.

[KCFZZ]

I think the cascading effect is pretty interesting... each explosion knocks loose more dust, priming the air for the next blast.

[paulcooper]

As a teenager, I was janitor at a wood-art hobby shop.
One of my first assignments was to use compressed air and a wand to clear wood dust from the suspended lights.
Until now I didn't realize just how dangerous that task was. My only protection was a face mask in literally a fog of wood dust.
All the doors were closed so dust would not enter the art facilities. That building would have been blown to smithereens by a spark.

[davidmicheletti]

I’ve seen this happen many time while working in the paper industry. The second or third explosions become so powerful.
I remember one time there was a fire and the fire department was working to contain the fire. The trouble was they were spraying the beams with water. While some of the dust became wet the majority of it remained dry and caused more and more fires to spread. The firemen were then ordered to stop spraying straight streams of water and just spray a fine fog of water in order to not raise more dust into the air. Then crews went to work with front end loaders to dig out burning bins of wood chips and wet them down outside the mill on the ground. This happened at a subsidiary OSB plant that we were called out to help. In time tricks were learn that would reduce the need for the fire departments to come the fight the fires. House keeping and learning how to deal with these fires were very effective.

[joehoe]

Very informative!! Should be shown in school woodworking class.

[anb]

I’ve seen this happen inside grain elevators. The results are catastrophic.

[Plumber]

Having worked in a lumber plant for 15 years.

They have suction hoses for anywhere they are cutting to catch 85% of the dust that is created. Tuesdays and Fridays over time was offered to walk around the plant sucking up piles of saw dust with a 10 gallon cordless vacuum on your back.

That had been part of the safety protocol for 200 years before I worked there. And Osha copied it and made it mandatory for lumber processing plants of all kinds in New Hampshire

[dwaynerobertson]

I worked for a short time at a (retired), grain elevator in Thunder Bay, Ontario. It was re-outfitted to make compressed pellets of wood for some new-fangled type, high efficiency furnaces. I wasn't working that day; Frank called me up and said he was at work. He had a pair of April Wine tickets (they were playing at the university pub), and he offered them to me. I said "EFF YEAH!!", and drove over to the elevator to get the tickets. I hung out with him and the guys working that afternoon/evening, for a bit, had a coffee and a smoke, shot the shit...and went home to relax before the night started. I missed that explosion by a few minutes, at most. No warning, and extremely volatile - instantly. The sound must have been deafening. From what I understand, it started in the basement and spiraled up the staircase, through consecutive floors, and it blew a massive section of the silo onto the ice where the big lakers would load up (in an inlet kind of protected area, on Lake Superior). Massive section of one side just KA-BOOMED. Frank sustained some nasty injuries, Darcy was probably close to death, throat swollen up and serious burns, but he survived. Man, I hope these guys are all still alive and well. The boss was a super guy...terrible event that took place that day, and the boss certainly didn't deserve that in his life. Who would? A brand new business, probably major personal and outside investment with promise of decent returns, he was employing people...went completely awry for everyone there, and I barely missed it. For me, just looking at the aftermath of the explosion(s), a few days after the fire dept, police, insurance were finished investigations, was frightening. Metal doors wide enough to accommodate forklift passage were bent and torn apart like a scene from the 2001 9/11 evil event. You'd probably need a forklift to install those doors -- they were huge steel doors. Looking straight down the staircase...straight up the staircase. MASSIVE detonation. The main room that we bagged the product in, and the shipping/receiving area basically, always had about 30 or 50 or maybe more skids, all loaded and shrink wrapped - they were blown all to hell. The power that that alone would require. Comparable to blowing seeds of off a Dandelion - that easy. Honestly, I don't know how any of them survived, looking at the aftermath. I didn't even see it all. I just saw the main area, the staircases I just looked up and down...and that massive section blown out the side of the silo onto the lake ice. That was more than enough for me to witness. The devastation on the boss's face...damn near as terrible as the elevator/silo itself. I shook his hand, said I am so damned sorry, and never saw him again. I think 5 guys were there that afternoon/evening shift, and they all survived. I have posted this same comment before, on a youtube video or two elsewhere. Quite the story...about dust.

[fastnbulbouss]

Wood dust is used in special effects in films to make explosions. We used to fill air canons with it and shoot it through windows....makes a huge flame that lasts only a few seconds and dies off. It's cheap, and available anywhere without a special permit.

[daltanionwaves]

Props to whoever did the 3D Animation. Beautiful work.

[Syclone]

I have a basement workshop at home with lots of sawdust from a radial arm saw, jigsaw, band saw, etc. I never thought of this hazard. My water heater has a pilot light. I wonder why you never hear of home workshop explosions? Is there any risk I need to watch out for?

[heronimousbrapson]

Years ago, many homes in Vancouver were heated with sawdust burning furnaces. This is likely one of the reasons they were ultimately banned.

[normferguson]

This is why shop dust collection systems are so important.

[richardcranium]

The coal used in power plants to generate electricity comes in as chunks but before is it delivered to the boiler it is ground into dust that’s as fine as powder. It helps with heat regulation and release.

[cliffcannon]

This is the first time I have seen a good explanation of how a small explosion lofts more dust to create a larger explosion, starting a rapid sequence of larger and larger explosions. The whole team behind this excellent video deserves the highest praise for a job well done.

[FordGTmaniac]

"Keep your nose to the grindstone" is one of those quotes that's often misunderstood. People think it means to simply work hard and pay attention to what you're doing, but its original meaning was for workers to use their sense of smell to identify when something was overheating (like a grindstone in a grain mill being pushed too hard), which was often their first and only warning before disaster could strike.

[johnnydawad]

I worked for a flooring manufacturer several years ago in the maintenance department. One of my jobs was to run a diesel engine bobcat in the dust accumulation building, and feed the auger that fed the sawdust fired boiler, the heat of which was used in the manufacturing process of the flooring. Sometimes the dust in the dust building was so thick, visibility was zero and you had to stop the Bobcat and wait a minute before you could see. How there was never a dust explosion is beyond me. One job Im glad I don't do anymore.

[InVinoVeritas]

I worked for years doing cleanup in a lumber mill. Trying to prevent exactly this. It never happened, but boy there were a lot of fires.

[robertthomas]

i had two coworkers die from such an explosion at the same time and it started with a boiler exploding.

[edwardianeccentric]

“This video should be viewed in conjunction with training in combustible wood dust hazard recognition and mitigation controls.”

Lol nah I’m here for the boom boom.