Alarm warns family of high CO levels

A carbon monoxide detector is credited with alerting four people to high levels of the deadly gas in a southeast Calgary home.

Three people have died from accidental carbon monoxide poisoning in the past month in Calgary.

The family called 911 when their detector went off Sunday evening and they smelled gas.

The fire department said initial readings came in at about 110 parts per million(ppm) and peaked at 240 ppm. In workplaces,Alberta Environment sets a maximum safe exposure level at 25 ppm based on an eight-hour shift.

Three adults and one child were treated by EMS crews, but no one needed to be hospitalized.

Officials from ATCO Gas said the combination of an old wood-burning fireplace and a partially blocked furnace ventmay have caused the elevated gas levels.

The fire department says the first line of defence is properly maintaining gas-burning appliances and ventilating fumes. The second is installing a carbon monoxide detector, which sells for about $60.