ENMET SPECTRUM-RAL - Manual (Page 15)

S PECTRUM RAL ENMET Corporation
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Appendix A Appendix A
The Characteristics and Effects of Carbon Monoxide
Carbon monoxide is a colorless odorless toxic gas generated by incomplete combustion of a hydrocarbon fuel in air. It
may be present where internal combustion engines, furnaces, boilers, and other combustion devices are present. It is
toxic when inhaled because of its great affinity to hemoglobin, the oxygen carriers in the red cells of the blood. CO
replaces the oxygen normally carried by the hemoglobin, and thus inhibits the delivery of oxygen throughout the body;
the victim suffers from oxygen deficiency, and may die from asphyxiation. The symptoms and degree of danger
resulting from exposure to CO depend upon the concentration of the gas and the length of exposure; this is shown in
Figure 6. The ENMET SPECTRUM-RAL carbon monoxide monitor is employed to warn the user of the presence of
CO, and to facilitate the assessment of the degree of danger that he or she is exposed to.
Based upon knowledge of the effects of CO, the Occupational Safety and Health Authority (OSHA) has set limits on
exposure to CO in the workplace. For ambient air conditions, these are 35
PPM (parts CO per million parts air) as an
time weighted average for an eight hour day, and a maximum exposure of 200 P P M . For compressed air line
applications, 10 PPM is the maximum acceptable limit. The SPECTRUM-RAL monitor is shipped with the adjustable
alarm set at 10 P P M ; this alarm cannot be adjusted above 50 PPM .
The curves below are for percent carboxalhemoglobin with 50% being the top curve, 5% the bottom. % COHb is a
measure of the amount of hemoglobin occupied by CO rather than oxygen. CO effects upon children, adults engaging
in physical activity, and smokers, are more pronounced.
Figure 6: % COHb vs Time