When work in the confined space, storage worse, waterproof creek narrow space, and poor ventilation place, if have the feelings like burning eyes, runny nose, choking, chest tightness or headache, dizziness, weakness, it may be acute asphyxiating gas poisoning or hypoxia.  

    To prevent being poisoned in the confined spaces, the following acts should be taken: First is to get ventilation; The second is to test the internal oxygen, the danger of, the concentration of harmful substances, electrical isolation, high temperature, low temperature, and hazardous substances in the confined space; at the same time, it is necessary to follow the practices and safety rules. Before entering a confined space,one  must get permitted, and be supervised, and also take oxygen-wearing gas masks the and automatic warning devices according to the regulations,  In addition, workers discovered poisoning, should do a good job in individual protection and rescue, not to rush to enter, so as to avoid unnecessary casualties.

    Common confined spaces are the caves, tunnels, the dumping of the buildings, sewers and other access channels, septic tanks, boilers, such as deformation of the car. Operating in the confined spaces may cause the following harms: lack of oxygen, suffocating; Hydrogen sulfide, carbon monoxide, and other harmful gas poisoning; Fire, explosion; Electric shock; Sandwiched by volume; fall; depressions, such as swallowing depression.