In a totally closed environment such as that of the nuclear submarine, exposure to raised ambient levels of carbon monoxide is continuous. The principles on which the maximum permissible concentration (MPC) for such exposure should be based are explored with particular reference to non-smokers and smokers, and to the effects on individual and overall system performance and on health. Reference to ambient carbon monoxide levels in submarines; induced carboxyhaemoglobin levels in smoking and non-smoking crew members; the financial, material and operational cost constraints on the MPC; and to current evidence regarding toxic levels, leads to an assessment of the MPC based primarily on safeguarding the non-smokers.The recommendation is made that the current submarine MPC of 25 ppm by volume should be reduced to 15 ppm, bringing it into line with recommendations for spacecraft, and providing an MPC which is applicable in any closed-environment situation.
展开▼
