As the weather turns colder throughout much of the country, the U.S. Consumer Product Safety Commission (CPSC) urges consumers to have a professional inspection of all fuel-burning appliances - including furnaces, stoves, fireplaces, clothes dryers, water heaters and space heaters - to detect deadly carbon monoxide (CO) leaks.

These appliances burn fuels - typically gas, both natural and liquefied petroleum; kerosene; oil; coal; and wood. Under certain conditions, these appliances can produce deadly CO. However, with proper installation and maintenance, they are safe to use. An annual inspection and service is the first line of defense against this silent killer.

CO is a colorless, odorless gas produced by burning any fuel. The initial symptoms of CO poisoning are similar to flu, and include headache, fatigue, shortness of breath, nausea and dizziness. Exposure to high levels of CO can cause death.

"Each year, CO poisoning associated with using fuel-burning appliances kills about 200 people," said CPSC Chairman Ann Brown. "Having this inspection performed could prevent a terrible tragedy."

CPSC recommends that the yearly professional inspection include checking chimneys, flues and vents for leakage and blockage by debris. Birds, insects and other animals sometimes nest in vents and block exhaust gases, causing the gases to enter the home. Leakage through cracks or holes could cause black stains on the outside of the chimney or flue. These stains and strange smells can mean that pollutants are leaking into the house. In addition, have all vents to furnaces, water heaters, boilers and other fuel-burning appliances checked to make sure they are not loose or disconnected.

Have your appliances inspected for gas leaks and adequate ventilation. A supply of fresh air is important to help carry pollutants up the chimney, stovepipe or flue, and is necessary for the complete combustion of any fuel. Never block ventilation air openings. Also, make sure the appliance is operating on the fuel that it is designed to use. An appliance must be modified by a professional to burn propane.

CPSC recommends that every home should have at least one CO alarm that meets the requirements of the most recent Underwriters Laboratories (UL) 2034 standard or International Approval Services 6-96 standard. CPSC worked with UL to improve the CO alarm standard to improve the reliability of alarms, and reduce the potential for nuisance alarming.

Consumers should also have the vent pipes on their heating systems inspected. In 1998, CPSC worked with the furnace and boiler industry and the manufacturers of high-temperature plastic vent (HTPV) pipes to conduct a vent pipe recall program. The program's purpose is to replace, free of charge, an estimated 250,000 HTPV pipe systems attached to gas or propane furnaces or boilers in consumers' homes. The HTPV pipes could crack or separate at the joints and leak CO. Consumers should call the recall hotline toll-free at (800) 758-3688, between 7 a.m. and 11 p.m. ET, seven days a week, to verify that their appliance venting systems are subject to this program.

CPSC continues to work with the furnace industry to develop new technologies to address the hazards of CO poisoning and fire. Results include a standard that added blocked-vent shut-off devices to protect against blocked vent pipes and chimneys, and requirements to guard against a vent pipe becoming separated from the furnace. Both of these conditions could lead to CO poisonings. Also, all gas-fired furnaces manufactured since 1987 have flame roll-out protection technology that prevents flames from shooting out of the furnace's combustion chamber and starting a fire.