CO is toxic, because CO binds to hemoglobin in the blood, so that the blood cannot bind well with oxygen, and people suffocate and even die due to lack of oxygen. This process can be represented as follows:
Hemoglobin - oxygen + CO = hemoglobin - CO + oxygen
This is a reversible reaction, when too much CO is inhaled, it will bind hemoglobin, causing hemoglobin to lose its function of transporting oxygen. According to the characteristics of reversible reactions, CO poisoning can be infused with oxygen to increase the biological concentration, and the chemical equilibrium will move in the direction of the reverse reaction and re-release hemoglobin.
Of course, CO cannot be emitted into the air, if the concentration of CO in the air reaches 50-55 ppm (mg/m3), it will cause poisoning. However, CO is flammable and emits a lot of heat when burned, so the ignition method can be used in large factories. The process is as follows:
2CO + O2 = 2CO2