Welding fumes ingredients of the use of different welding vary. Electrode welding core and the coating composition. In addition to the core wire contains a lot of iron, there are carbon, manganese, silicon and the like; coating within the material mainly consists of marble, fluorspar, manganese and other components. When welding, arc discharge a 6000 ℃ 4000 ℃ high temperature, melting the electrode and weldments, while generating a lot of smoke, which composed mainly of iron, manganese, silica, silicate, grain dust filled in the operating environment and can easily be inhaled into the lungs. (B) the harm of toxic gases at high temperatures and strong ultraviolet light produced by the welding arc around the arc area will produce carbon monoxide, nitrogen oxides. 1, carbon monoxide, a colorless, odorless, non-irritating gas, it easily with human hemoglobin to transport oxygen in combination, and is extremely difficult to separate, therefore, when after a lot of hemoglobin and carbon monoxide combined with the hemoglobin loses oxygen opportunity to combine, so that the body transport and use oxygen dysfunction, resulting in tissue due to hypoxia and necrosis. 2, nitrogen oxide, a toxic gas with a pungent smell, which often come into contact with nitrogen oxides mainly nitrogen dioxide. It is reddish-brown gas with special smell, when inhaled through the respiratory tract into the alveoli, to work gradually with water to form nitric acid and nitrous acid, to produce severe lung irritation