Carbon monoxide has been blamed for the death of one man at a Winnipeg business and for making 20 others ill.

Manitoba Fire Commissioner Dave Schafer confirmed Friday the business was located at 287 Taché Ave. The multi-storey building served as offices for Lombard North Group.

Officials were called to the business after people complained they felt ill. The building was evacuated and one person was taken to hospital and is recovering there.

It wasn't until later that officials were told a man had been found unresponsive in the building the previous day. He was rushed to hospital with what staff presumed was a heart attack and later pronounced dead.

An autopsy has since confirmed the cause of death was carbon monoxide poisoning.

'Be very vigilant'

An investigation has found that a vent cover on the chimney had collapsed, preventing the deadly gas from escaping.

Schafer said the building doesn't have any carbon monoxide detectors, but because it's a commercial space, it's not required to.

Since 2011, any new construction in the province has been required to have carbon monoxide detectors installed, but Schafer said only certain types of buildings were required to put them in retroactively.

"This isn't a location where people are sleeping," Schafer said of the office. "People are usually awake, and that's where we put the emphasis on, where people are in the care of others or sleeping."

Schafer said his message to the public is to "be very vigilant," especially this time of year.

Marc Proulx

Winnipeg Fire Paramedic Service public education coordinator Marc Proulx said people should be extra cautious about carbon monoxide poisoning during the colder months. (CBC)

Carbon monoxide is an odourless, colourless gas that can result from combustion any time fuel is burned in cars or trucks, small engines, stoves, lanterns, grills, fireplaces, gas ranges or furnaces. It can build up indoors and poison people and animals who breathe it.

Those qualities have earned it a reputation as "the silent killer," said Winnipeg Fire Paramedic Service public education coordinator Marc Proulx.

He said it's typically produced by fossil fuel-burning equipment including furnaces, fireplaces and vehicles.

It makes people sick by replacing oxygen molecules in blood, and builds up with continued exposure, he said.

That means the risk of poisoning is higher this time of year as people are using their furnaces and fireplaces more aggressively and spending more time indoors.

The most common symptoms of CO poisoning are headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion. They are often described as flu-like.

How to stay safe

Schafer said all property owners have a responsibility to make sure their equipment is well-maintained, including repairs and annual inspections.

Make sure vents are clear too, he said, especially after a snowstorm.

Beyond that, Proulx said your best protection is a carbon monoxide detector.

A simple battery-operated unit is enough for the average home, Schafer said.

If you think you have too much carbon monoxide in your space, these are the steps Schafer recommends:

  • Shut off the fuel burning appliance, if you know what it is.
  • Open doors and windows to air the building out.
  • Call your gas provider, whether it's natural gas or propane, and request an emergency inspection.