Dellcos FM-CO User Manual page 17

You may wish to unplug the CO Alarm and store in a
plastic bag during the project.
The following is a list of substances that at high levels
can affect the sensor and cause an alarm.
Methane, propane, iso-butane, ethylene, ethanol, alcohol,
iso-propanol, benzene, toluene, ethyl acetate, hydrogen,
hydrogen sulfide, sulfur dioxides.
Also most aerosol sprays, alcohol based products, paints,
thinners, solvents, adhesives, hair sprays, aftershaves,
perfumes, auto exhaust (cold start) and some cleaning
agents.
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