Originally Posted by **********

Both compounds contain carbon and oxygen, the difference lies in their toxicity. Carbon dioxide (CO2) contains one molecule of carbon and two molecules of oxygen. Carbon Monoxide (CO) contains only one atom of oxygen and two atoms of carbon.

Sit in closed garage with a gasoline engine car running and you will pass out and then die because you are taking in too much CO.

Put your head in a plastic bag and seal it around your neck and in a few seconds you will pass out and die because you are taking in too much CO2.

Now... Dihydrogen monoxide, that's a real killer, right Robbie? ;)