Two carpet cleaners were using a truck-mounted unit to clean carpets in an unoccupied townhouse. The truck was parked in a garage attached to the townhouse and the main garage door was closed. The door from the garage into the townhouse was open so that the hoses could run from the cleaning unit into the house.

Throughout the day, the cleaning unit was running. Its engine used gasoline for fuel. Carbon monoxide from the engine built up and entered the open door into the townhouse. Both carpet cleaners died from carbon monoxide poisoning.

Carbon monoxide is a gas produced during the combustion of fuels such as gasoline, diesel, and propane. Victims of carbon monoxide poisoning cannot see or smell this gas so they don't realize they are in danger.

• Park vehicles with truck-mounted cleaning units outdoors. Do not run engines fuelled by gasoline, diesel, or propane inside buildings or enclosed areas.
• Follow the manufacturer's safety instructions.
• Watch for symptoms of exposure to carbon monoxide such as headache, watery or itchy eyes, rosy cheeks, nausea, weakness, and dizziness. If you or co-workers have any of these symptoms, immediately get to fresh air in an open area. Call for medical help.
• Do not enter an area that is suspected to have high levels of carbon monoxide. Phone for emergency help. You could lose consciousness too quickly to rescue a victim or escape yourself. Even emergency personnel must enter only if they are trained and equipped to rescue someone in a hazardous atmosphere.
• Follow a plan to check on the well-being of workers who are working alone.