Highly complex mixtures of organic vapor pollutants are found in the atmospheres of both nuclear submarines and SeaLab II. There are continuing sources of these and they must be removed by proper use of activated carbon or by catalytic burning. In both craft the concentration of methane increases with time because it is not removed easily and there are continuing sources. Tobacco smoking in submarines generates large quantities of carbon monoxide which is catalytically burned. Its presence in significant quantities in SeaLab II is not fully explained. The low oxygen concentration in SeaLab precludes fires.
