1.5 Arc Welding and Cutting Safety
Welding and cutting is considered “hot work” by the National Association of Fire Prevention. Whenever welding or cutting is done outside of the shop, the welder may be required to obtain a “hot work” permit from the local fire department. Many fires occur in buildings in which arc welding or oxyfuel cutting is being done. These fires can start when hot metal droplets or sparks are projected from the weld or cutting area into other areas that contain flammable materials. Posting a fire watch is an important safety procedure to help prevent fires. See Heading 1.4.2, covering fire prevention and fire watches. Wherever appropriate, the safety precautions mentioned in the general shop and oxyfuel gas safety sections of this chapter should be applied to arc welding and cutting operations. Many of the safety hazards involved in arc welding and cutting deal with the dangers of work with and around electricity. The American National Standard ANSI 249.1, Safety in Welding, Cutting, and Allied Processes, suggests that a notice similar to the one shown in Figure 1-22 be placed on major equipment used in an arc welding process. 1.5.1 Electrical Hazards A safety inspection of the arc welding station should be made regularly by the welder. With the welding machine power off, the cables should be checked over their entire length for worn or cut insulation or exposed wires. Cable connectors should be checked for tightness. The electrode holder or welding gun should be checked for cracked insulators, loose contacts, and worn or cut hoses. To avoid electrical shocks, a welder should never work with wet or damp gloves or while standing on a wet or damp floor. If work must be done under such conditions, a floor of nonconducting material should be built up above the wet areas. Welders who must weld in a seated or lying position should sit or lie on an insulated material or mat. Electrical repairs should be attempted only by qualified electricians. Repairs to feed wire drives should be made only with the power off. Nothing other than the base metal, electrodes, and approved welding cables should ever be used to carry welding current. |
1.5.2 Arc Ray Hazards
An arc welding face shield with the correct filter shade number lens must be worn while welding. Refer to Figure 1-7. The face shield protects the eyes, face, and neck from burns caused by the ultraviolet or infrared rays emitted by the electric arc. It also protects against flying sparks, Figure 1-23.
1.5.3 Breathing Hazards
Arc welding must be done with good ventilation, with proper protective clothing, and with the same precautions described in the general and oxyfuel gas welding safety sections. Ventilation should always be arranged so that the fumes are picked up before they reach the welder's eyes, nose, or mouth. The hazards from toxic fumes are the same for the arc welding processes as they are for all other forms of welding. See Figure 1-9 and refer to Headings 1.3.2, 1.3.3, and 1.3.4 to review the safe limits for various air contaminants that can be found in welding fumes and the proper safety precautions to minimize exposure.
1.5.4 High-Pressure Cylinder Hazards
When high-pressure shielding gases or other gases are used, cylinders must be stored, moved, and fastened down as described in the oxyfuel gas safety section. Regulators must be operated and cared for in the same way as oxygen or acetylene gas regulators.
1.5.5 Burn Hazards
Burns are the most common injury encountered in the welding or cutting processes. Burns can occur to the body or eyes. Burns to the body generally are caused by ultraviolet or infrared rays given off when welding. They may also occur from hot metal or molten metal thrown off while welding. Wearing appropriate clothing for the work involved is the best way to prevent body burns.
There are three classifications of burns. The classifications are: first degree, second degree, and third degree burns. A first degree burn occurs on the outer surface of the skin. First aid for this type of burn is the application of cold water or cold water compresses to the burn area.
With a second degree burn, the surface of the skin is severely damaged with small breaks in the skin and blisters appearing on the surface. First aid for such a burn involves applying cold (not freezing) water and cold water compresses. The burn area is then covered with sterile bandages or pads. Do not apply ointment, butter, or any other home remedies. A doctor should be seen for further treatment.
The third degree burn is the most serious. The surface of the skin will appear white or charred like burned meat and the third or deeper layer of the skin may also be severely damaged with nerve and blood vessel damage. It is suggested that in first aid for the third degree burn that NO water or ice be placed on the burn area. Also, NO clothes should be removed from the burned area of the body. This may further damage the skin and place the patient in further pain or shock. DO NOT put ointment, antiseptics, or any home remedies on the burn area. Cover the wound with sterile dressings. Call an ambulance or take the patient to the nearest hospital.
An arc welding face shield with the correct filter shade number lens must be worn while welding. Refer to Figure 1-7. The face shield protects the eyes, face, and neck from burns caused by the ultraviolet or infrared rays emitted by the electric arc. It also protects against flying sparks, Figure 1-23.
1.5.3 Breathing Hazards
Arc welding must be done with good ventilation, with proper protective clothing, and with the same precautions described in the general and oxyfuel gas welding safety sections. Ventilation should always be arranged so that the fumes are picked up before they reach the welder's eyes, nose, or mouth. The hazards from toxic fumes are the same for the arc welding processes as they are for all other forms of welding. See Figure 1-9 and refer to Headings 1.3.2, 1.3.3, and 1.3.4 to review the safe limits for various air contaminants that can be found in welding fumes and the proper safety precautions to minimize exposure.
1.5.4 High-Pressure Cylinder Hazards
When high-pressure shielding gases or other gases are used, cylinders must be stored, moved, and fastened down as described in the oxyfuel gas safety section. Regulators must be operated and cared for in the same way as oxygen or acetylene gas regulators.
1.5.5 Burn Hazards
Burns are the most common injury encountered in the welding or cutting processes. Burns can occur to the body or eyes. Burns to the body generally are caused by ultraviolet or infrared rays given off when welding. They may also occur from hot metal or molten metal thrown off while welding. Wearing appropriate clothing for the work involved is the best way to prevent body burns.
There are three classifications of burns. The classifications are: first degree, second degree, and third degree burns. A first degree burn occurs on the outer surface of the skin. First aid for this type of burn is the application of cold water or cold water compresses to the burn area.
With a second degree burn, the surface of the skin is severely damaged with small breaks in the skin and blisters appearing on the surface. First aid for such a burn involves applying cold (not freezing) water and cold water compresses. The burn area is then covered with sterile bandages or pads. Do not apply ointment, butter, or any other home remedies. A doctor should be seen for further treatment.
The third degree burn is the most serious. The surface of the skin will appear white or charred like burned meat and the third or deeper layer of the skin may also be severely damaged with nerve and blood vessel damage. It is suggested that in first aid for the third degree burn that NO water or ice be placed on the burn area. Also, NO clothes should be removed from the burned area of the body. This may further damage the skin and place the patient in further pain or shock. DO NOT put ointment, antiseptics, or any home remedies on the burn area. Cover the wound with sterile dressings. Call an ambulance or take the patient to the nearest hospital.