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Welding, Cutting, and Heating (Hot Work)

Each year numerous deaths from explosions, electrocutions, asphyxiation, falls, and crushing injuries are associated with welding activities. These deaths often involve confined or restricted spaces. In addition, numerous health hazards are associated with exposure to fumes, gases, and ionizing radiation formed or released during welding, cutting, and brazing, including heavy metal poisoning, lung cancer, metal fume fever, flash burns, and welders flash (burn to the eyes).

A. Before workers begin a welding operation, the following controls must be established:

1. No welding is permitted in an explosive environment. 4848
   
2. A written “hot work” permit is recommended whenever a combustible environment may exist. 4848
   
3. All combustible materials in the work area must be removed or guarded. 4848
   
4. Suitable fire extinguishers, that meet NFPA and ANSI Standards, must be provided in the work area. 4848
   
5. Employers must instruct employees on hot work safety. 4848(a)
   
6. Welders must be required to wear:
   
   1. Non-flammable gloves with gauntlets. 1520
      
   2. Appropriate foot protection. 3385
      
   3. Aprons (leather) and shirts that have sleeves and collars. 1522(a)
      
   4. Helmets, hoods, and face shields suitable for head protection. 3381(a), 3382(a)
      
   5. Suitable eye protection. 3382
      
   6. Respiratory protection (as required). 5144
      
7. Screens must be provided to protect the eyes of nonwelders from flash burns and ultraviolet light rays. 3382(b)
   

B. Gas welding is regulated as follows:

1. Fuel gas and oxygen hoses must be distinguished from each other. 1742(a)
   
2. Couplings must not disconnect by means of a straight-pull motion. 1742(g)
   
3. Oil or grease must never come into contact with oxygen equipment. 1743(c)
   
4. Oxygen from a system without a pressure regulation device must never be used. 1743(e)
   
5. Gas cylinders must be stored and used as follows:
   
   1. Cylinders must be protected from all heat sources. 1740(a)
      
   2. They must be secured upright and placed so they will not fall or be knocked over. 1740(c)
      
   3. Cylinders must be handled in suitable cradles, with their valve caps installed; they must never be lifted by magnet, rope, or chain. 1740(c), (d)
      
   4. They must be guarded so that they never form a part of any electrical circuit. 1740(e)
      
   5. Fuel gas cylinders in storage must be separated from oxygen cylinders by a minimum distance of 20 ft. or by a noncombustible barrier that is at least 5 ft. high and has air re-resistance rating of a 1/2 hour. 1740(g)
      
   6. Valve stem wrenches must be left in place while cylinders are in use. 1743(g)
      
   7. A fire extinguisher rated at least 10 B:C must be kept near the operation. 1743(j)
      
   8. Backflow protection is required. 4845(b)
      

C. Arc welding is regulated as follows:

1. Cables in poor condition must not be used; no cable may be spliced within 10 ft. of the electrode holder. 4851(e)(2)
   
2. The frames of arc welding and cutting machines must be grounded. 4851(f)(5)
   
3. Electrodes and holders that are not in use shall be protected so they cannot make electrical contact with employees or conducting objects. 4851(g)
   
4. Defective equipment must not be used. 4851(j)
   

D. Ventilation requirements for welding, cutting, and brazing operations aim to minimize the worker’s exposure to hazardous fumes, gases, and vapors. 1536, 1537

1. Outdoor operations
   Respirators are required for any operation involving beryllium, cadmium, lead, or mercury. For other operations and materials, respirators are not required when natural or mechanical ventilation is sufficient to prevent exposure to airborne contaminants in excess of the PELs noted in 5155. 1536(c)
   
2. Indoor operations
   Respirators shall be used when local exhaust or mechanical ventilation is not feasible or able to prevent exposures that exceed limits specified in 5155.
   

E. In enclosed spaces supplied-air respirators shall be used when local exhaust ventilation is not an effective means for preventing potentially hazardous exposures. 1536(b), 5152