A 14-year-old working at a Saskatchewan grocery store almost died after being exposed to 60 times the regulated level of carbon monoxide. The teen had been instructed to clean an enclosed area of the meat department using a gas-powered pressure washer.

The young worker began to feel seriously ill but managed to stagger to the front of the store. He was airlifted to hospital and spent hours in a hyperbaric chamber to pump oxygen into his blood and carbon monoxide out. He survived but is being monitored for long-term health effects, including heart, pulmonary and neurobehavioural function.

“Breathing in carbon monoxide prevents the body from using oxygen properly, which can harm the brain, heart and other organs,” explains WSPS Consultant Tova Larsen. “Serious effects can happen within minutes.” While this incident occurred in a grocery store, it could occur in many types of Ontario workplaces,” says Tova, unless employers take preventative action.

A true hidden hazard, carbon monoxide is often called ‘the silent killer’ because it gives no clear warning. “It is an incredibly poisonous gas with no taste or smell,” notes Tova. “The first effects include headache, faintness, nausea and fatigue, which a worker may mistake for symptoms of the flu and ignore unless they have received training. Continued exposure can cause confusion, loss of consciousness and even death.”

What types of work could expose workers to carbon monoxide?

“Workers may be at risk in any sector where natural gas, propane, oil, gasoline, diesel, wood or other carbon fuels are used or when working in a building heated by these fuels,” says Tova. “In 2016, a worker in Manitoba died in an office building with a malfunctioning boiler.”

Risk mounts further when carbon fueled equipment, such as generators, pressure washers, or chainsaws, are used in an enclosed space. A space doesn’t need to be fully enclosed or indoors for carbon monoxide to build up quickly. “Even in partially enclosed outdoor spaces, such as alcoves, covered areas, open barns, or garage bays with the door open, accumulations can occur. Moving tools outdoors nearby doesn’t eliminate the risk. The exhaust can be blown inside through open doors or ventilation systems by wind.”

In warehouses, carbon monoxide can be generated from material handling equipment, such as propane or diesel fork trucks, but can also enter the workplace from idling vehicles at loading bays. Parking garages, auto shops, foundries and steel mills and manufacturers also use carbon fuels as a heat source in production equipment.

Lesser-known at-risk sectors include restaurants with gas stoves, ovens, charcoal grills, coffee roasters, or craft brewing. Patio heaters are also a major concern. “Nearly every patio has them, and many patios are covered and/or partially enclosed,” says Tova. “Coffee roasters are at particularly high risk because the beans continue to off-gas carbon monoxide after roasting.”

7 tips for controlling carbon monoxide risks

Employers have legislated duties when it comes to workers’ exposure to carbon monoxide. Under sections 3 and 4 of Ontario Reg. 833, Control of Exposure to Biological or Chemical Agents, every employer must take all measures reasonably necessary to protect workers from exposure to hazardous biological or chemical agents.

“The regulation outlines control measures employers can use to limit exposures to below the time-weighted average threshold limit value of 25 ppm over eight hours, as set by the American Conference of Governmental Industrial Hygienists (ACGIH).”

In addition, employers should follow these 7 tips, says Tova.

1. Choose electric or battery powered tools instead of gas-powered tools.
2. Install continuously monitoring interconnected carbon monoxide detectors with audible and visual alarms in multiple locations in the workplace, such as in proximity to heating systems, process equipment, cooking appliances, loading bays and exterior doors.
3. Ensure adequate ventilation systems at all times but especially if using carbon-burning power sources indoors, such as propane powered fork trucks, process equipment, and cooking appliances.
4. If you must use gas-powered equipment, place the power unit in an open space outdoors far away from doors and air intakes. Check wind direction to ensure exhaust is moving away from the building.
5. Train workers and supervisors on the risks and symptoms of CO exposure – headache, nausea, weakness, dizziness, visual disturbances, changes in personality and loss of consciousness. Any of these symptoms and signs can occur within minutes of starting the equipment or after longer exposures.
6. Have effective emergency response systems in place. Evacuate the workplace at the first sound of an alarm. Affected workers need medical attention, and possibly specialized treatment depending on severity. Moving an affected worker to fresh air is not enough to remove carbon monoxide from the body.
7.  Maintain and use all carbon-fueled equipment according to manufacturers’ instructions and specifications.

How WSPS can help

WSPS’ occupational hygiene consultants can help you identify and control carbon monoxide and other atmospheric hazards in your workplace. Connect with a consultant.

Resources

• Carbon monoxide: 5 ways you and your JHSC can protect everyone against this deadly hazard
• Protecting Against Respiratory Hazards (guideline)
• Carbon monoxide poisoning in workplaces (Ontraio.ca)

The information in this article is accurate as of its publication date.