Every year, carbon monoxide (CO) kills 200 to 300
Americans and poisons more than 5,000 others. This poisonous
gas — which can't be seen, tasted, or smelled — can
originate from a wide variety of sources, including a car or
lawn mower left running in an attached garage, improper
venting of a kitchen range, or a cracked or disconnected vent
pipe for a combustion appliance (see illustration above).
As construction technology has advanced, the danger of carbon
monoxide poisoning has actually increased. Chimneys in
tighter, energy-efficient houses are more likely to backdraft, and
high-efficiency heating units now produce cooler flue gases that
are less likely to vent naturally. Consumer awareness is