Common causes of gas poisoning: 1. Using a coal stove for heating and cooking in a closed room can produce a large amount of carbon monoxide accumulation in the room due to poor ventilation and inadequate oxygen supply. (1) Doors and windows are closed, and there is no ventilation, not installed or incorrectly installed air hopper; (2) negligence, paralysis, resulting in a large amount of gas overflow; (3) chimney installation is not reasonable, the mouth of the tube is facing the wind, so that the gas backflow; (4) bad weather conditions, such as wind, snow, cloudy days, low gas pressure, it is difficult to circulate gas discharge. 2, urban residents use piped gas, the amount of carbon monoxide is 25-30. if the pipeline leakage, the switch is not tight, or cooking in the flame was extinguished, the gas overflowed a lot, can cause poisoning. 3, the use of gas water heaters, poor ventilation, bathing time is too long. 4.Starting the car in the garage in winter or sleeping in the car after turning on the air conditioner in the car can cause gas poisoning. Because the car exhaust contains carbon monoxide 4-8, a 20 horsepower car engine can produce 28 liters of carbon monoxide in a minute. 5. Other things such as gun smoke from blasting in mines, fertilizer plants using gas as a raw material, equipment failure, pipeline leakage, etc. can cause gas poisoning.