Dust… Spark… Inferno

InfernoCombustible dust is a deadly wood-industry hazard. Postive steps can help prevent explosions from two sources: regulations and fire.

Four workers have been killed recently, and 42 more injured, as a result of explosions erupting in two B.C. sawmills. Although the investigations — by both the Crown and WorkSafeBC — are ongoing, combustible dust is yet again suspected as the culprit in a wood-industry workplace disaster. Fines may be levied against the employing companies, and individuals may even be facing criminal prosecution.

Think it can only happen in a large sawmill? Think again. Jamison Scott, vice president and corporate officer for Air Handing Systems, has also served as the Wood Machinery Manufacturers of America’s (WMMA) point-man on combustible dust. He says, “Whether we’re talking about a big sawmill or a small manufacturer, too many people in our industry are unaware of the extreme dangers involved with this hazard.”

There are many reasons for this lack of awareness. For one thing, wood-shop explosions don’t happen every day. Complacency can set it. For another thing, although there is a tremendous amount of information out there on the topic, making any sense out of it can be overwhelming

First, although various jurisdictions in Canada and elsewhere define combustible dust differently, the Canadian Centre for Occupational Health and Safety (CCOHS) has a rather common sense definition at the ready: “A combustible dust is any fine material that has the ability to catch fire and explode  when mixed with air.” Combustible dust can come from such organic materials as wood and grain — or even sugar and flour.

According to CCOHS guidelines: “Any activity that creates dust should be investigated to see if there is a risk of that dust being combustible. Dust can collect on surfaces such as rafters, roofs, suspended ceilings, ducts, crevices, dust collectors and other equipment. The guideline continues: “The build-up of even a very small amount of dust can cause serious damage.”

As evidence of such serious damage, Scott has created a demonstration video, and has even received the attention of CBC News. In the video, a small amount of wood flour blew the lid off of a sealed jar after exposure to a small spark. According to Scott, “If such small materials can cause such a large effect, imagine what can happen in a wood shop.”

As with many occupational health and safety hazards, combustible dust can lead to two types of explosions: the real, physical kind, and the legal kind. For Scott, both can be avoided with simple prevention. He says, “People are amazed at just how straightforward prevention can be. I am so involved in this issue for a couple of reasons. First, I don’t want people to get hurt. Second, I don’t want people facing a legal mess if the regulators get involved.”

Jamison Scott
Jamison Scott

Scott believes both types of explosions can be avoided. According to him, “One of the easiest preventative measures is simple sweeping. Don’t let piles of sawdust collect on the floor or anywhere else. When you do sweep, you can’t do it too vigorously, or else you’ll just disperse the dust instead of collecting it.”

Leakage is another area where diligence can prevent problems down the road. Scott says, “It really does depend on the size of the shop. For larger operations, an entire maintenance team can be trained to maintain equipment, look for leaks, and fix problems when necessary. In a small shop, a couple of people might have to do it all, but we’re really only talking about taking a few minutes out of a day, or a few hours in a month.”

For Scott, prevention really should be part of a larger trend occurring in the wood industry today: lean manufacturing. As he describes it, “Shops across North America are training their employees to engage in more efficient operations. That’s exactly what should be happening with health and safety. If workers are in the habit of doing the small things correctly, it no longer becomes a worry. It becomes second nature.”

Christopher Liddy is an occupational health and safety specialist with CCOHS. He also believes that a routine of prevention is achievable in wood shops across Canada. According to Liddy, “The general approach that any organization should take is to implement an occupational health and safety program where they identify, assess and control hazards in the workplace.”

According to Liddy, “Specific issues surrounding combustible dust in the workplace may vary depending on the nature of the activities conducted on the worksite. Organizations should develop and implement a site-specific plan and program that address the hazards on the worksite, and then follow-up to evaluate their effectiveness. Workers should be trained on the hazards in the workplace and how to identify them as well as the controls that are put into place.”

Liddy points to WorkSafeBC, the worker’s compensation board of B.C., as an excellent source of information on best practices in dealing with wood dust. This should come as no surprise, since the province has needed to respond to two of the biggest wood-related explosions in recent memory. Yet their resources on the issue are symptomatic of a larger challenge related to combustible dust: there is no single source to turn to for information on prevention, or regulation — both here in Canada and in the U.S.

Let’s take the publication WorkSafeBC has made available on its website. It’s called Wood Dust in Sawmills: Compilation of Industry Best Practices. Dedicated to the memory of workers that have died from combustible-dust hazards, this document is a smorgasbord of best practices taken from various sources, including primary-wood producers, a forestry council, the WMMA, and even the United Steelworkers. At almost 400 pages in length, it doesn’t serve as an easy guide for any business — large or small.

If you’re looking for more clarity south of the border, you might want to look elsewhere. Wood-industry facilities across America are being fined and penalized despite the lack of a specific federal regulation on combustible dust.

Says Scott, “Although the OSHA [Occupational Health and Safety Administration] has tended to use the NFPA’s [National Fire Protection Association] standards on wood dust as a guide, they usually resort to the “general duty” provision of their current regulations, which can make it difficult for manufacturers to know what specific compliance provisions are necessary.”

Here in Canada — as is the case with most issues on health and safety — we have at least 10 different sets of regulations (even more if you count federal regulations as well as those from the territories) on combustible dust because we have 10 provinces, which tend to have regulatory jurisdiction. CCOHS, which is the federal government’s resource guide on occupational health and safety, has literally nothing to say on regulation and compliance.

According to CCOHS communications officer, Ashleigh Blackmore, “Our mandate is to offer best practices, resources and information on subjects related to occupational safety, but we generally don’t speak to the legislation or different laws that exist in various jurisdictions.”

So what’s a wood-industry professional that wants guidance on combustible-dust compliance to do? A two-tiered approach might help. On the one hand, learning about all the prevention measures available, regardless of jurisdiction, will help in local compliance. For example, routinely sweeping up floor dust will probably impress an inspector in Kamloops as much as one in Trois-Rivières.

On the other hand, as with most safety compliance issues, getting in the practice of doing some homework in your province might go a long way. We can help get you started. First, the federal government is not completely without regulation on combustible dust. Section 17.11 of Canada Occupational Health and Safety Regulations specifically covers combustible dust as a hazard. It’s available at the Justice Laws Website.

Several provinces have regulations that specifically pertain to combustible dust, including Newfoundland and Labrador, Quebec, Ontario and B.C. Ontario even has regulations covering the processes leading to combustible dust. Section 63 of the Occupational Health and Safety Act includes this provision: “A process involves risk of ignition or explosion that creates a condition of imminent hazard to a person’s health or safety.” It can be found online, too.

Other jurisdictions, including Saskatchewan, Manitoba and Alberta, address combustible dust as a general fire or health hazard. This makes sense in that dust that is combusted can and will lead to fires. The federal law also treats combustible dust as a fire hazard. Manitoba’s laws include a definition of flammable substances that covers combustible dust. In Alberta, a workplace can be defined as a hazardous location if it is at risk of fire due to combustible dust.

Some Canadian jurisdictions, such as Nova Scotia, New Brunswick and Prince Edward Island, treat combustible dust in a different manner by banning certain kinds of work under certain kinds of conditions. For example, welding or soldering in the presence of combustible dust is prohibited in these jurisdictions. In New Brunswick, such work is to be done only after an area has been inspected for and cleared of combustible dust.

Yet, regardless of what laws are to be looked up in your local jurisdiction, regulatory compliance doesn’t necessarily make your workplace safe. It’s employers that have to learn about hazards such as combustible dust,  and take preventative measures, and it’s the employees that need to be trained and encouraged to practice prevention at all times. In other words, laws don’t create working conditions that prevent combustible dust from exploding, people do.

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