>>2855205since op is concerned of carbon monoxide, and though he's about propane and butane, i'd recommend a spirit stove (trangia and similar brands) using methanol (methil alcohol).
methanol is on every Chinese store here, and readily available. it's toxic, so dont drink it, but is kind of safe if you dont do much contact or inhale much of it.
point is, it has one single carbon atom, so it combines stechiometrically perfect with an oxygen molecule (2 oxygens) making perfect combustion: no monoxide but maybe some traces.
the stove has no mechanical pieces: long life. just learn how much alcohol you'll need for every dish and it's all.
it's cheap also. silent, etc.
very happy with it, inside a boat, at home, etc. i use it with no ventilation if it's rough outside. no problems by now. stable, and if you take the time to learn the amount of alcohol, you can forget about it, as, when the lentils are done, alcohol is finished. no risk to forget and burn.
you can use any alcohol, also: ethil alcohol (sanitary one), isopropyl, even vodka, but the only one which will not soot black your pots is still methanol.
take care.
