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FUMES and GASES can be hazardous to your health.
Keep your head out of the fumes. Do not breathe fumes and gases caused by the arc. Use enough ventilation. The type and the amount of fumes and gases depend on the equipment and supplies used. Air samples can be used to find out what respiratory protection is needed.
Provide enough ventilation wherever welding and cutting are performed. Proper ventilation will protect the operator from the evolving noxious fumes and gases. The degree and type of ventilation will depend on the specific welding and cutting operation. It varies with the size of work area; on the number of operators; and on the types of materials to be welded or cut. Potentially hazardous materials may exist in certain fluxes, coatings, and filler metals. They can be released into (lie atmosphere during welding and cutting. In some cases, general natural-draft ventilation may be adequate. Other operations may require forced-draft ventilation, local exhaust hoods or booths, or personal filter respirators or air-supplied masks. Welding inside tanks, boilers, or other confined spaces require special procedures, such as the use of an air supplied hood or hose mask.
Check the welding atmosphere and ventilation system if workers develop unusual symptoms or complaints. Measurements may be needed to determine whether adequate ventilation is being provided. A qualified person, such as an industrial hygienist, should survey the welding operations and environment. Follow their recommendations for improving the ventilation of the work area.
Do not weld on dirty plate or plate contaminated with unknown material. The fumes and gases which are formed could be hazardous to your health. Remove all paint and galvanized coatings before welding. All fumes and gases should be considered as potentially hazardous.
Do not weld near vapor degreasers or on metal that has been just degreased. The decomposition of chlorinated hydrocarbons used in vapor degreasers can form into a poisonous gas.
Additional information on various fumes and gases that can harm your health is located in the Appendix of this booklet. More complete information on health protection and ventilation recommendations for general welding and cutting can be found in the American National Standard Z49.1, “Safety in Welding and Cutting”.
ELECTRIC SHOCK can kill you.
Do not touch live electrical parts.
Live electrical parts can include the power supply, the power and work cables, the torch and the work itself (if the work is not connected to earth ground.)
Electric shock can be avoided. Follow the recommended practices listed below. Faulty installation, improper grounding, and incorrect operation and maintenance of electrical equipment are always sources of danger.
  • Connect electrical equipment and workpiece correctly. Prevent electrical shock.
    • Connect power supply and control cabinet chassis to approved earth ground
    • Connect workpiece to “work” output connection of power supply
    • Connect workpiece (as illustrated below) OR power supply work terminal (but not both) to approved earth ground. “Double-grounding” can cause welding/cutting current to occur in conductors intended only for safety grounding and can result in destruction of the safety ground.
      NOTE: The work lead is NOT a ground lead; the work lead is to be used only to complete the welding circuit
  • Make good electrical connections of the work lead to the power supply work terminal and to the workpiece. A missing or poorly - connected work lead can cause a fatal shock. Make sure the work lead is always in good condition
  • Use the correct cable size. Sustained overloading will cause cable failure and result in possible electrical shock or fire hazard. Work cable should be the same rating as the torch cable
  • Make sure all electrical connections are tight, clean, and dry. Poor electrical connections can heat up, and even melt. They can also cause bad welds and produce dangerous arcs and sparks. Do not try to make an electrical connection through paint. Do not allow water, grease, or dirt to accumulate on plugs, sockets, or electrical units
  • Insulate yourself from workpiece and ground. Moisture and water can conduct electricity. To prevent shock, it is advisable to keep work areas, equipment, and clothing dry at all times. Fix water leaks immediately. Keep hoses from touching hot metal. Do not exceed recommended water pressures. Make sure that you are well insulated. Wear dry insulated gloves, rubber-soled shoes, or stand on a dry board or platform
  • Use only the proper equipment if welding must be done in electrically-hazardous conditions. Such conditions include damp or warm locations, wet clothing, metal structures such as floors or scaffolds, cramped positions or wherever there is a high risk of contact with workpiece or ground. In any of these situations use :
    • DC MIG welding
    • DC manual (stick electrode) welding
    • AC welder with reduced open-circuit voltage control
  • Keep cables and connectors in good condition. Improper or worn electrical connections can increase the chance of an electrical shock. Do not use worn, damaged or bare cables
  • Avoid open-circuit voltage. Open circuit voltage of welding, cutting and gouging power supplies can cause electric shock. When several welders are working with arcs of different polarities, or when using multiple alternating current machines, the open-circuit voltages can be additive. The added voltages increase the severity of the shock hazard.
  • Remove metal jewelry. It is recommended that rings, watches, necklaces, and other metallic items be removed before welding or cutting. Accidental contact of jewelry with welding power can cause metal to become hot or even melt. It can also increase the possibility of a fatal shock
  • Follow recognized safety standards. Follow the recommendations in American National Standard Z49.1, “Safety in Welding and Cutting,” available from the American Welding Society, P. 0. Box 351040, Miami, FL 33135, and also the National Electrical Code, NFPA No. 70, which is available from the National Fire Protection Association, Batterymarch Park, Quincy, MA 02269
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