Canadian Biomass • Summer 2022 • Mind your dust

A decade ago, two people died and 20 were injured in an explosion at the Babine Forest Products facility in Burns Lake, B.C. Just three months later, two more people died and 22 were injured in a similar explosion at Lakeland Mills in Prince George, B.C. The incidents, caused in part when fine sawdust from wood ignited, are a sombre reminder of the importance of dust management programs in the wood manufacturing industry.

“Tragically, we know too well that if combustible dust is not managed properly, it can catch fire and burn or cause a deflagration and explosion, potentially resulting in serious and life-threatening injuries to workers,” says Budd Phillips, prevention field services manager at WorkSafeBC.

Over the past decade, WorkSafeBC has seen significant progress to ensure the hazards associated with combustible dust are effectively managed, by working alongside industry partners and employers to share and promote tools, techniques and knowledge about wood dust mitigation and control.

However, recent factors such as the COVID-19 pandemic and timber supply issues have impacted plant operations and changed the work environment in many mills and wood processing facilities. In addition, the risks can be hard to spot. Combustible dust can accumulate in out-of-site areas like basements, ceiling beams, and trusses.

“Over the past couple of years, manufacturers have been impacted significantly. Many have had to vary their production levels or reduce their workforce, which may draw resources away from proper maintenance and evaluation of dust management programs — leaving them vulnerable to potential hazards,” Phillips says. “Employers need to stay focused.”

Phillips says now is the opportune time for all employers to revisit their dust management programs. “Dust management programs should be constantly evaluated to ensure they meet the needs of current operations and keep workers safe.”

This begins with a risk assessment to determine what operations are generating dust and where vulnerabilities exist in any given workplace. Find someone qualified – such as a health and safety professional or industry representative – to assess the fire and explosion risks associated with combustible dust.

“Look at your processes, equipment, and buildings to ensure you can accurately evaluate your current handling practices, equipment, fire extinguishing systems, and other dust mitigation efforts,” Phillips says.

Risks should be logged in a comprehensive report that is readable and well-presented. When the risks are clearly defined and understood, optimal controls can been identified, and implemented – typically through a combination of robust cleaning programs and engineering controls – to mitigate dust build-up when it exceeds allowable limits.

“While cleaning processes are important, there is also a human factor to consider,” adds Phillips. “Ensuring cleaning crews are conducting proper assessments and can keep up with the pace of work can sometimes be challenging in a plant that generates lots of dust.”

Phillips says that high-speed chainsaws can generate 33 pounds of sawdust per minute in multiple locations, which is why capturing dust at its source is critical to a successful dust management program.

Employers should examine ventilation systems to ensure proper airflow and have mechanisms to encapsulate dust such as covering conveyers. Employers should also ensure proper electrical cabinetry is in place and cleaned properly so it does not become an ignition source.

“There are many engineering controls available that extract excess dust more effectively and also help monitor dust levels. For example, some mills have comprehensive monitoring systems that include new sonic fans that help remove dust from high elevation surfaces.”

However, enhanced technology does not replace the need to consistently evaluate dust management programs to ensure they’re sustainable. Plans should be re-evaluated and new risk assessments should be done if any of the following occur:

“The smallest change in personnel or operations could make a difference, so employers must regularly evaluate their programs to ensure they have the capacity required to keep dust levels below the allowable limits,” says Phillips.

Even if nothing changes in a workplace, employers should review their programs at least once a year to ensure they meet occupational health and safety standards, and do not put workers at risk.

Phillips says most employers know their business and are aware of where and when dust is generated. The challenge is controlling and mitigating it.

Engineers that specialize in ventilation can also provide employers with a detailed assessment of a system’s effectiveness.

WorkSafeBC’s prevention efforts, inspection initiatives and collaboration with industry partners have been successful in combating combustible dust in wood manufacturing. One of the challenges, however, is providing guidance and regulation to support smaller operations and other industries that face similar risks.

“Current legislation does not address all industries that are generating hazardous amounts of combustible dust, like cabinet shops for example,” Phillips says.

Pulp and paper waste, commercial laundry facilities, iron fillings, and sugar plants are just a few examples of the thousands of manufacturers that could experience catastrophic outcomes if dust levels from those products accumulate over certain levels.

“Our current regulations for combustible dust are minimal in terms of what we can require for combustible dust programs, and are limited to specific employers groups,” explains Phillips. “Since our combustible dust strategy was developed in 2012, we realized that there is a significant risk in many industries that needs to be addressed to keep workers safe.”

New proposed legislation changes are currently in the consultation phase in B.C. These revised regulations will become part of the B.C.’s Occupational Health and Safety Regulation providing WorkSafeBC prevention officers with the opportunity to enforce safety programs in a broader range of industries.

In the 10 years since the sawmill explosions in Burns Lake and Prince George, there has been significant progress and tangible improvements in managing hazards associated with combustible wood.

“We owe it to those who lost their lives or were injured to never forget the impact those explosions had on their families, their job sites and their communities – and to remain vigilant in order to prevent a tragedy like that from ever happening again,” Phillips says.

WorkSafeBC has developed several dust management resources, available on their website: www.worksafebc.com/en •

Alexandra Skinner is a manager of government and media relations with WorkSafeBC.