Canadian Occupational Safety (COS) magazine is the premier workplace health and safety publication in Canada. We cover a wide range of topics ranging from office to heavy industry, and from general safety management to specific workplace hazards.
Issue link: https://digital.thesafetymag.com/i/1164813
27 2019 OCTOBER/NOVEMBER combustion can leak into the work area and expose workers to carbon monox- ide or other hazardous substances. The workers who install the system must be certified or licensed by the provincial regulatory authority, such as Technical Safety B.C., which con- ducts practical testing to ensure a technician's competence. "People may not be fully trained on how to install properly. They may take shortcuts because of budget pres- sures, time pressures or simple lack of knowledge. They're getting into a business in which they are not fully qualified," Lalli says. In jurisdictions with a permit system, such as British Columbia, companies need to apply for an instal- lation permit and for an operating permit for equipment of a certain size. Technical Safety B.C. will then conduct annual inspections of the equipment to determine if it is still being main- tained and operated properly. As well as the venting, other items of equipment can go wrong. One of these is the burner, Sanderson says. If the burner, which is intended to act as a controlled air-fuel mixing device, is not getting the correct air-fuel ratio, it may not mix the fuels correctly. "As a result, you may get incom- plete combustion, which can cause the wrong products of combustion to come off. For example, you may get higher aldehydes or carbon mon- oxide. If it's out of tune, you may get more greenhouse gases, such as NOX, which are nitrous oxides." Valves also need to be inspected regularly for fuel leakage, he adds. Valves are mechanical devices that have "seats" and "seals" that create barriers to control flow. These seats and seals can wear out. "With time, debris and throttling, the seats and seals will age, get brittle and eventually leak. All valves leak. It's a question of what is an accept- able rate of leakage. Is it one drip per year, one drip per day or one drip per second?" Sanderson says. "So, annually, many of the sys- tems are supposed to be inspected and checked for leakage. By doing an annual inspection, you can docu- ment how a seat or seal is leaking: Is it increasing? Is it wearing out? And you can try to be preventive on that." An inspection should also include a check of the many safety switches and devices that monitor the valves, he adds. For example, pressure switches should be examined to make sure pressure isn't too low or too high, which could be indicative of equip- ment failure. Safety interlock devices, as well, should be checked to make sure they are working properly. Lack of proper maintenance is a common problem, Marshall says. Boilers should be cleaned regu- larly and venting systems should be checked. When a venting system becomes blocked, due to debris or squirrel or bird nests, the heating unit may continue to operate, but, instead of sending the fumes up the chimney, it may spill them out into the workplace, exposing workers to carbon monoxide. That could put at risk not just those in the area but all the people in a building or factory. "The key is regular maintenance and inspection," he says. "That's one of the most important things you can do to protect workers. That's a require- ment in the [Occupational Health and Safety] code. Owners and users must maintain their equipment in safe working order. That means you should be following the maintenance requirements recommended by the manufacturer. You should be cleaning the units, and if you see that the piping or venting is starting to rust and deteri- orate, then you might want to do some work or look at replacing something." One common cause of incidents involving combustion systems, Lalli says, is management decision-mak- ing and responsibility. In one 2017 incident, in which an explosion in a natural gas-fuelled boiler caused vent- ing to collapse, Technical Safety B.C.'s investigation found the boiler had not been serviced in the three years since its installation, although the manufac- turer recommended annual servicing. A responsible manager recognizes the necessity to follow manufacturers' instructions and the need to comply with both the provincial OHS code and regulator, he says. "The manager says, 'I have to be responsible and comply, despite the fact that it may cost money, downtime or hassle.'" One critical aspect of managers' decision-making is asset management, he adds. As the Fernie curling rink inci- dent showed, managers must monitor the age of equipment and be willing to replace those pieces of equipment before they fail, injuring workers and causing damage to facilities. "We need to make people aware, what is your end-of-life strategy for this equipment? Have you put a budget aside? Have you increased maintenance? Have you increased your inspection frequency? Are you taking into account this is aging equipment and it's going to become more risky as time goes on?" Lalli says. "It's surprising to see that a lot of companies, large and small, either are not aware of it or turn a blind eye." Everyone who works with or ser- vices thermal energy equipment must be trained on that equipment, Mar- shall says. If a food manufacturing facility, for example, has a malfunc- tioning oven, a trained worker would know to call in an expert technician, instead of repeatedly trying to light the oven. An untrained worker might not realize the oven is not working. "If the person hasn't been properly trained, they may try re-lighting that oven over and over again. At some point, they'll get a combustible mix- ture in that oven and it will light, but it will also have an explosion," Lalli says. "Sometimes, there may be what we call a delayed ignition, which is fairly minor, and the user might get a flash back and a minor burn. But, sometimes, they're much more criti- cal than that. In a factory, there can be a boiler explosion." Training should continue through a technician's working life, Marshall says. No matter how thorough, the person's initial training for certifica- tion cannot possibly cover the many different scenarios they are likely to encounter. Certainly, re-training is essential where a technician who is experienced working on smaller appliances plans to start working on larger equipment, such as an indus- trial boiler. Following the Fernie curling rink tragedy, Technical Safety B.C. issued a province-wide safety order requiring all public facilities with ammonia refrigeration systems to test their equipment. The regulator's investigation into the incident pro- duced 18 recommendations, some aimed at improving maintenance of ammonia chillers, including regular monitoring of aging systems. During the investigation, Lalli says, they found a large number of munici- pal ammonia refrigeration systems were more than 25 and even 30 years old. Yet, as statistics show, systems over 30 years old are bound to fail. "We did a thorough investigation into that incident and shared our knowledge with the public. We got the message out. Now we're seeing a lot of municipalities and cities putting a priority on budgets to replace this aging equipment because we've made them aware," he says. "We've affected that change we're hoping to make." COS Linda Johnson is a freelance journalist based in Toronto. She has been writing for COS for eight years. a culture of unconditional dedication to safety