Carbon Monoxide (CO)
Carbon monoxide is a product of the incomplete combustion of carbon compounds and is absorbed by inhalation. The relative toxicity of CO increases with altitude. Carbon Monoxide (CO) is absorbed by the blood in the alveoli and competes with oxygen for haemoglobin.
The haemoglobin has a greater affinity for the CO than it does oxygen (approximately 200 times). The stable compound carboxy-haemoglobin is formed and because of this the amount of oxygen available for absorption is reduced by as much as 10%.
CO is deadly; being colourless, odourless and tasteless. It has a four hour half-life in air.
Carbon monoxide does not naturally occur in any quantity in the atmosphere. Its effects can be cumulative and are not easily corrected. Oxygen does not bring quick relief and several days may be required to rid the body completely of carbon monoxide. The presence of carbon monoxide results in hypoxia where it can have the same effect as an altitude increase of 8,000 to 10,000 feet.
The symptoms of carbon monoxide poisoning are headache, dizziness, weakness, nausea, rapid heart beat, respiratory failure and death. After death a person shows a redness in the lips and cheeks.