Ottawa fire responds to fatal levels of carbon monoxide in multi-unit home

Ottawa Fire Services responded to a call Monday morning, reporting the presence of carbon monoxide (CO) inside a residential multi-unit house.

Around 10:56 a.m. on March 31, Ottawa Paramedics were responding to a medical call that found possible exposure to the toxic gas when they requested that OFS attend to the scene to investigate the possibility of carbon monoxide inside the home.

Four minutes following dispatch, firefighters arrived to the Glebe four-unit rooming house, wrote Ottawa Fire Services on X.

Equipped with CO detectors, fire crews entered the three-storey home— with four separate addresses — in the 0-100 block of Ralph Street.

According to Ottawa fire, firefighters reported initial readings of 140 parts per million (ppm) in the first unit they entered, with readings of 330 ppm in the basement near the boiler, which was then switched off.

Following detection of fatal levels of CO, residents were evacuated and an OC Transpo bus was called to provide shelter.

A second team entered another unit and discovered readings of 280 ppm at the front door, 300 ppm on the second level and over 999 ppm near the boiler in the basement.

Carbon monoxide levels this high can be fatal within minutes, noted OFS.

Following the discovery of alarming CO levels, firefights began evacuating residents from all four units.

Officials confirmed the source was the boiler in the basement, showing the highest readings of CO in the home. Firefighters proceeded to use high pressurized fans to ventilate all four units within the residence and monitored air quality until the readings dropped to zero.

Ventilation operations concluded at approximately 1:24 p.m. yesterday, when an investigator from Ottawa fire took charge of the scene.

While Carbon Monoxide has no taste, colour, or smell, residents are advised to evacuate immediately and call 911 if they suspect CO exposure.