In any construction project involving explosives, care must be taken to protect workers from carbon monoxide (CO) generated by blasting operations. CO is an odorless, colorless gas that can cause illness and death by asphyxiation. In general, the first symptoms include headache, fatigue and lightheadedness. At higher exposures to CO, skin flushing, rapid heart rate, and lowered blood pressure occur. At even higher exposure levels, decreased attention span is followed by nausea, vomiting, impaired coordination, fainting, coma, convulsions and, finally, death. The detonation of explosives in blasting operations generates a range of toxic fumes, but CO is the most insidious because it is colorless, odorless, and is long lasting, since it is not readily removed by reaction with ground water, soil or rock.
NIOSH Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236