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Dangers of dust

By COS staff
| www.cos-mag.com
Dust explosion at Imperial Sugar Refinery in Port Wentworth, Georgia on February 2008

Combustible dust has the potential to cost significant damage to life, limb and livelihood, yet information about these hazards is scarce — and the lack of knowledge is putting many workers at risk.

If you were one of the many American industrial workers on the morning of February 7, 2008 unaware of the threats posed by combustible dust, there’s a good chance that things changed pretty quickly by the following morning. That’s because on the evening of the 7th, Imperial Sugar’s Port Wentworth, Georgia, sugar refinery exploded, killing 14 workers and injuring 40, in what has been described as the most catastrophic North American dust explosion since 1980.

The blaze occurred almost four years after the U.S. Chemical Safety Board (USCSB) conducted a study that highlighted the dangers of combustible dust, following three high-profile incidents in 2003 that saw 14 workers killed. That same study made a number of recommendations to the U.S.’s Occupational Safety and Health Administration (OSHA) in the interest of improving preventative regulations — but only a portion of them had been implemented at the time of the Imperial explosion.

Though the overall awareness, regulations and preventative practices surrounding the issue of dust explosions were already beginning to change across the U.S., the incident at Imperial was a wake-up call. Regulatory bodies and health and safety professionals quickly realized it was a serious issue, and one that needed to be addressed immediately to prevent any future tragedies from happening. Legislation was passed. Employers and employees were educated. Plants were temporarily shut down for renovations and refurbishment. The culture began to change and change fast.

Sleeping neighbours

We’re now over three years removed from the Imperial explosion — and while the incident has spurred on its southern neighbours to implement better hazard control and safety management in industries with higher risk of combustible dust — not much has changed in Canada.

“In the States, based on the CSB report, OSHA actually went ahead and started getting much more involved because of all the fatalities that they had,” notes Laurence Polley, president of C&R Engineering Solutions, Inc. and a combustible dust advocate here in Canada. “A lot of states passed laws, and OSHA passed some more laws, so it’s very, very much on their radar screen down there. Up here, to my knowledge — certainly in Ontario and I’m guessing across the country — there has been no activity on the regulation front. It’s kind of business as usual.”

One of the biggest obstacles facing those trying to raise awareness about the topic of explosive dust in Canada is the lack of comprehensive statistical data on this hazard.

“One of the problems you would find if you went to try and get reports of fires caused by dust explosions is that it’s not something that’s captured with the statistics up here,” Polley says. “It’s there in black and white. We do have fires, some of which I’m sure are partially caused by dust explosions. We just don’t look at them that way.”

The fire reporting system currently employed in Canada, the Canadian Code Structure for Fire Loss Statistics, has been ineffective in adequately documenting the incidence and ignition sources of combustible dust fires, according to John Astad, a combustible dust expert based in Texas. It’s an issue that Astad sees down in the States, as well, though not to the same extent as in Canada.

“[Combustible dust fire reporting] isn’t good in our system either,” he says. “I was looking at the Canadian Code Structure— it’s called the CCS— and yours is more watered down than ours; and we still need to do a lot of work on ours. We need to work together more. Your Canadian Fire Code uses the NFPA as a reference. There’s over half a dozen National Fire Protection Association codes for combustible dust— they’ve got codes for wood, for metal, for food parts for sulphur. They’ve got codes for explosion ventilation and explosion suppression.”

What’s missing, though, are data elements that require fire responders to discern the source of ignition for each fire, says Astad, who is also the director and research analyst with the Combustible Dust Policy Institute — an advocacy site dedicated to minimizing the severity and occurrence of combustible dust-related fires and explosions through ongoing exchange of best practices and lessons learned from combustible dust related incidents.

“I’m doing a little bit of research on something called Co-FIRS, or the Computerized Fire Instant Reporting Systems. I’m reviewing it and it’s missing equipment involving ignition. Many of your combustible dust fires start in the dust collectors or in the ductwork. When you do incident reporting, if you don’t report on the equipment involved in ignition, how are stakeholders going to be able to evaluate it and control it comprehensively? How are you going to raise national or provincial awareness without having the correct data elements?”


Because many combustible dusts have relatively low ignition sensitivities when compared with other flammable materials, combustible dust fires can be caused by something as minor as sparking equipment; even cumulative heat created by mechanical friction can cause an explosion. When these types of fires and their causes go unreported, employers and employees alike fail to see the prevalence of dust-related fires and the ways in which they can be prevented. With better statistical fire reporting, however, Astad believes advocates can effectively raise more awareness of the issue and promote better preventative practices.

“Once we have this information,” notes Astad, “then you actually have the information, education and outreach to the facilities, so there’s more awareness.”

Normalization of deviation

One obstacle standing in the way of better statistical fire reporting is something Astad calls the “normalization of deviation.” He points out minor combustible dust fires happen all the time, and can usually be contained with little to no assistance from a local firefighting authority. In cases where the fire department is called to the scene, the effort to extinguish the fire is often so minimal that the incidents go unreported; in cases where they’re not, the incidents rarely make it beyond the company’s outer walls.

“It’s called normalization of deviation,” says Astad. “No catastrophic incidents have occurred, no incidents have occurred where you’ve had fatalities, and no incidents have occurred where you’ve had injuries. Say I own a business and I’ve been doing it for ten or fifteen years. I know the fire department — they come out regularly and put out fires in my dust collector and my ductwork. Nothing bad ever happens. Basically it’s called a smoke scare. The first doesn’t go outside the dust collector, and it doesn’t impinge on the structure. A lot of times the workers at the facility put it out with hoses and fire extinguishers.”

Astad points to an industrial fire that broke out this past January in a hopper building at a manufacturing warehouse in Caledon, Ontario, as an example. It took 80 firefighters and six hours to contain the blaze, and the damage done to the building was estimated at $250,000. The fire occurred at a site the local fire department was well familiar with: They had made numerous visits to the grounds dating back to August 2003, and had extinguished at least four previous fires in that same time period.

In a news report about the Caledon fire, the local fire chief said he feared the possibility of a full-on dust explosion while his crew worked on the roof of the building. The fire chief also acknowledged the nature of the process in that company — which reportedly manufactures medium density fibre board sheet and trim — and felt it was just the nature of their business.

Polley says it’s an opinion all too common amongst fire responders and business owners. Summarizing the view many stakeholders hold regarding dust fires, he says, “[For them,] it’s business as usual. It didn’t blow up, and in a lot of cases I don’t even think the fire departments even become aware of some of the smaller little dust explosions that happen within a facility.”

It’s this sort of resigned complacency that makes Astad uneasy. When fire response teams accept the inevitability of fighting these sorts of dangerous and potentially preventable fires, and business owners understand them and their financial impact as an unavoidable consequence of their processes, the goal of raising awareness and reducing catastrophic dust explosions becomes more difficult to achieve.

“The incident reporting is very important,” he says. “It brings life to the subject. It’s one thing to tell someone that they need to do this or they need to do that, but once they see these actual incidents — these lessons learned — it starts opening up a lot more eyes and bringing awareness to the subject.”

As much as it frustrates him, Astad understands why these attitudes exist. “An explosion is a very rare event,” he says. “You look at the thousands and thousands of businesses, and it’s very rare.”

While that may be true, he also knows that as rare as they are, dust explosions can cause immeasurable loss when they do happen. “People get injured and killed. It’s about awareness of the fire hazards, and of the dust. It can create a lot of harm — death, injury, property damage, etc.”

The way he sees it, something’s got to give.

The bottom-line

The reality of minor dust fires is they are often precursors to full-on dust explosions. Failing to address repeated minor dust-related fires and minimize the hazards, employers run the risk of suffering a far more serious incident that could potentially have far greater financial consequences.


Polley believes that financial factor is another obstacle standing in the way of greater awareness of the issue and the possibility of implementing safer work practices. As he points out, one of the first steps to diagnosing a potential dust explosion threat is getting your dust tested, and that comes at a price.

“One of the problems is that, in order to get your dust tested, it gets very expensive,” he says. “Typically, if you want to run a series of tests on what you suspect might be combustible dust, you’re going to be looking at anywhere from $5,000 to $15,000, so it’s not an inconsequential [number]. You’re not taking it to the hardware store and getting it done for $100.”

But while those numbers are no small potatoes, they pale in comparison to the cost of damages and lost productivity for even the smallest of dust fires. Consider, for example, the fire that occurred in Caledon earlier this year, which cost the company $250,000 in damages alone — that’s before factoring in lost productivity, and doesn’t include any fines that might be levied against the company for health and safety violations. When you see the numbers side-by-side like that, it’s clear that taking necessary safety precautions is a pretty wise investment.

However, conducting dust test is just one of many steps to help protect against combustible dust explosions — and right on top of that list is awareness. Even with the recent string of high-profile incidents in the U.S., Polley says there are still plenty of issues people aren’t aware of when it comes to combustible dust.

Among them, he says, is the fact that “there’s still an awful lot of people who have no idea what’s explosive and what isn’t.”

“It’s not totally visible,” he adds. “It’s not like a machine guard where you look at it and it’s obvious it’s a hazard. People can wade through dust and not even think about it.”

Visible or not, the threat is pervasive, and exists across a wide variety of materials and processes. “It’s amazing how broad the product spectrum is under which you can have dust fires and dust explosions,” notes Polley. “It’s plastics, it’s rubbers, it’s agricultural, it’s some metals, it’s foodstuff.”

Without knowledge of the threat posed by combustible dust, it’s hard to protect against it in the first place. “Most people don’t know that they may have a potential situation and that they should therefore get their dust tested.”

Another problem Polley sees with the current state of affairs is the question of who is responsible for raising awareness on the issue. While he feels it’s important that all interested parties seek to raise awareness and bring the issue to the forefront, he says that’s not always the case. “Most equipment manufacturers don’t do a risk analysis on how [their equipment] is going to be used. They sell it as is and turn the problem over to whoever is going to plug it in.”

“A lot of companies are aware of this,” he adds. “Certainly insurance companies are aware of it. Anybody that’s insured through the factory mutual sort of groups . . . the insurance company is sometimes the one that says, ‘No, you’ve got to put explosion-proof equipment in this area because of the dust problem.’ No other regulatory agency has really stepped up to the plate.”

Astad says awareness can start with health and safety practitioners. “Regulation is fine, but it needs to go hand-in-hand with education and outreach to the stakeholders, and working with different associations.”

Good place to start

One thing both Astad and Polley feel strongly about is the importance of Material Safety Data Sheets (MSDS) in informing stakeholders of the danger posed by combustible dust. When asked what the next step is for raising the profile of combustible dust in Canada, Polley said adding additional information about explosive dust to MSDS is a good start.

“The problem is that the MSDS doesn’t give proper indication whether something is actually explosive in dust form,” he says. “Think about candy manufacturers for sugar and sugar substitutes. If you get the regular MSDS for sorbitol, which is a sugar substitute, it doesn’t say anything about it being explosive as a dust. If you dig deeper — which I did, because I had an application where I didn’t believe the MSDS — you find out the information. An engineer is trained to dig deep and make sure he has all the facts, whereas a joint health and safety committee is just going to accept the piece of paper.”

The real importance of having this information available on MSDS, as Polley points out, lies in its ability to inform health and safety professionals who may not have the technical background to understand the dangers posed by combustible dust in the workplace.

“Let’s assume you have a properly functioning joint health and safety committee, and somebody is reviewing MSDSs and doing risk analysis,” he explains. “If it’s not even identified on the MSDS, those people aren’t going to know to go any further. If they read it and did their analysis, they would then be asking questions and then hopefully someone would take it further; but if it’s not even there to trigger a question, everybody’s going to assume it’s okay.”

The guidelines for MSDS requirements in Canada are established under the Workplace Hazardous Materials Information System (WHMIS), which is administered federally by Health Canada. According to a statement from the federal agency, between 2009 and 2010, it conducted a national outreach campaign to remind suppliers of their obligations to communicate the hazards and precautionary measures related to combustible dusts under an existing requirement of WHMIS’s Controlled Products Regulations (CPR).

The CPR, however, does not set out specific classification criteria for the explosiveness of dusts, and addresses only the intrinsic hazards of products and materials. Because dust explosions are the result of an interaction between materials and outside conditions, the issue falls outside the scope of the CPR — in accordance with the Canadian Constitution— falling instead into the jurisdiction of Canada’s provinces and territories as a labour issue, the Health Canada statement said.

Health Canada also indicated that the United Nations Sub-Committee of Experts on the Globally Harmonized System for the Classification and Labelling of Chemicals (GHS) has convened a working group to address the issue of dust explosion hazards, as well as what information should be included in the GHS. Canada is a member of the working group. However, it is not anticipated that the project will be completed before 2013. According to the statement, Health Canada is currently considering possible regulatory changes as well.

For their part, both Astad and Polley remain cautiously optimistic. Astad understands we will never be able to eliminate dust explosions completely: the processes and materials used in so many industries today are such that minor explosions are bound to happen. He hopes, however, that with greater awareness and better preventative efforts, we can avoid seeing anything like what happened in Georgia in February of 2008.

“Because of the inherent nature of the manufacturing process, you’re never going to get rid of your primary combustible dust fires and your primary combustible dust explosions,” he admits. “But you can minimize the probability and reduce the severity. That’s why they have explosion ventilation panels, dust collectors, and isolation valves and explosion suppression in the ductwork. They’re always going to have [incidents] in the industry, but we don’t want these catastrophic secondary events.”

Polley, meanwhile, just hopes that day would come sooner rather than later. “I just hope we don’t find out about how big the problem is when we end up with a tragedy on our hands, that’s all.”

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