Common arc welding hazards and Prevention

the common welding hazards include arc light, smoke, toxic gas, burning, fire and electric shock, which constitute the six major occupational hazards of arc welding< 1. Welding arc. 1ntense arc light will cause acute and chronic damage to eyes and skin. Electro optic ophthalmia is a common occupational disease of arc welder. Excessive exposure of the eye to ultraviolet light in arc light can cause keratoconjunctivitis. 1n light cases, there are foreign body sensation and mild discomfort in the eyes. 1n severe cases, there are burning sensation and severe pain in the eyes, accompanied by photophobia, tears, facial spasm and other symptoms2. Welding fume. Welding rod, weldment and coating produce a lot of harmful smoke and dust under high temperature, which is one of the main factors to pollute the welding environment. The main components of dust are iron, aluminum, manganese, copper, zinc oxide, silicon and so on, and the main toxic substance is manganese. Long term inhalation of metal dust by welders will cause occupational diseases such as pneumoconiosis and manganese poisoning< 3. Welding gas. Under the action of arc light, air will produce toxic gases such as nitrogen oxides. 1n the absence of good ventilation conditions, the toxic gas content in the air of welding site is several times or dozens of times higher than the national standard, which is very harmful to human body< 4. Welding scalding. The high temperature electric arc makes the metal melt and splash, which is easy to burn the human body. When the weld is knocked to remove the slag in welding, the slag that is not completely cooled is easy to hurt the eyes< 5. Welding fire. High temperature arc will make metal melt and splash. 1f there are flammable and explosive materials around, it may lead to fire or explosion accidents< 6. Welding electric shock. When changing the welding rod, the welder should contact the electrode directly by hand. 1n case of electrical failure, protective equipment defects, violation of operating procedures, electric shock accidents may occur. Especially in the surrounding metal objects and wet environment welding, more chances of electric shock, greater risk in order to eliminate all kinds of unsafe and unhygienic factors in welding and do a good job in the prevention of arc welding occupational hazards, the following preventive measures should be taken 1. 1n order to avoid the radiation of arc light to human body, the automatic filter welding mask should be worn. 1t is not allowed to directly watch the arc light with eyes near or peek away from the protective mask; When multiple welding machines are working, non combustible or flame retardant protective screen shall be set; Absorbing materials are used as interior wall finishes to reduce arc reflection; Ensure the lighting in the workplace and eliminate the situation of ignition first and then wearing automatic filter welding mask due to unclear vision of welding seam; 1t is not allowed to change the color number of the filter arbitrarily; The process is reformed, and the manual welding is changed into automatic or semi-automatic welding, so that the welder can work far away from the welding site2. For the protection of metal dust and toxic gas, the reasonable protective equipment should be selected according to different welding processes and occasions; 1n technical measures, local and comprehensive ventilation methods are selected; 1n order to reduce the concentration and toxicity of smoke and dust, low pollution or mechanization, high degree of automation and low dust and low toxic electrode are selected 3. 1n order to prevent welding burning, work clothes, work shoes and welding caps should be worn. Work clothes should be pure cotton with thick texture and good anti scalding effect. Pay attention to foot protection, do not wear fusible chemical fiber socks. The welding area should be clean, the welding pieces should be stacked together, and the cold and hot welding pieces should be placed separately. When dealing with welding slag, the neckline should be well tied and protective glasses should be worn to reduce burning injury accidents 4. Remove flammable and explosive materials from the welding site in advance; A fire plate shall be set under the high altitude welding; The flammable liquid containers and empty barrels should be cleaned and replaced thoroughly; 1t is not suitable for welding and cutting in simple buildings, warehouses, closed roofs of houses and near the stacking of inflammables; Welding in the cabin can prevent the heat conduction of steel plate from causing the back combustible or heat insulation layer to catch fire; When the pipeline and equipment for transporting and storing flammable liquid and gas to be repaired are connected with other equipment, the connected pipeline shall be removed or isolated< 5. 1n order to avoid electric shock, the welding machine grounding and all wiring points should be in good contact; The cable insulation jacket is not damaged; 1t is necessary to connect the secondary circuit to change the welding joint; The power supply must be cut off when the work place is transferred or the fuse is replaced or when the welding machine fails to check; Wear insulating gloves when replacing welding rod; When welding on metal containers or metal structures and narrow workplaces, rubber pads, insulating gloves, welding masks and insulating shoes should be used; The shell insulation of welding tongs should be reliable China labor insurance net