Co is a colorless, odorless gas that is toxic at high concentrations Its toxicity stems mainly from its ability to form a stable compound with hemoglobin(血红蛋白) called carboxyhemoglobin. Co has an affinity for hemoglobin 200 times more than that of O2 Co tends to block the normal distribution of oxygen in the body and leads eventually to suffocation The effect of co on people is a function of concentration and duration of exposure 100 ppm for 10 hours-headaches and reduced ability to think clearly 300 ppm for 10 hours- nausea and possibly loss of consciousness 600 ppm for 10 hours-death can result 1000 ppm -unconsciousness occurs in 1hr and death in 4 hrsCO is a colorless, odorless gas that is toxic at high concentrations. Its toxicity stems mainly from its ability to form a stable compound with hemoglobin (血红蛋白) called carboxyhemoglobin. CO has an affinity for hemoglobin 200 times more than that of O2 . CO tends to block the normal distribution of oxygen in the body and leads eventually to suffocation. The effect of CO on people is a function of concentration and duration of exposure. • 100 ppm for 10 hours — headaches and reduced ability to think clearly • 300 ppm for 10 hours — nausea and possibly loss of consciousness • 600 ppm for 10 hours — death can result • 1000 ppm — unconsciousness occurs in 1hr and death in 4 hrs