Although gas cooking ranges do emit carbon monoxide (CO), a well tuned (flame color), non-standing pilot flame (electronic ignition) produces minimal CO when the time involved in the useage as well as the size of the room in which the stove is installed is considered. Stuidies here in the U.S. show natural gas (NG) as well as bottled gases (propane, etc.,) CO emissions are primarily related to the use of the standing pilot lights, which are now mostly outdated and the pattern of use... Old fashioned standing pilot lights once used in ovens were the worst offenders...