Pressure Washing Operation Leads To Carbon Monoxide Incident

A carbon monoxide (CO) incident at a west side apartment building was the result of a gas-powered pressure washer being used inside the building. No occupants reported feeling ill, but 911 was called after an alarm activated in a third floor hallway.

Engine Co. 4 responded to the 700 block of Knickerbocker Street, entered the building, and proceeded toward the third floor. While in the elevator, firefighters’ air monitors alerted them to CO levels of approximately 80 parts per million (ppm). On the third floor, readings clocked in around 60-70 ppm. Firefighters retrieved a fan to begin ventilating the hallways, and that’s when they identified a cleaning crew on site. The cleaning crew stated they were using a gas-powered pressure washer in the basement to clean the floor of the parking area. By this time, the crew had already completed its work, but they were advised not to use gas-powered equipment indoors again.

Engine 4 returned upstairs and began methodically ventilating each floor of the building to clear the air. The garage doors were propped open to ensure thorough air exchange in the area where the pressure washer was used. Firefighters cleared from the scene after confirming all CO levels were below 5 ppm.