Welding Safety

Welding Safety - OSHA Standard

Any time metals are welded together, toxic fumes, gases, and sparks develop. To ensure that the health of machine operators is protected, it's critical that proper extraction systems are implemented in environments where welding equipment is being operated.

The severity of welding fume exposure is based on three things:

1. How effective the current extraction system is.
2. What type of welding takes place.
3. How long an operator is exposed to hazardous particulate.

Welding gases do not always have an odor and because of their submicron size can't be seen by the human eye which makes them exceptionally dangerous.

The heat from a welding flame has the ability to produce carbon dioxide, carbon monoxide, and oxides of nitrogen. Fumes and gases also develop through coatings or solvents used on the metal being welded.

Prolonged exposure to welding contaminants can result in severe injuries such as metal fume fever, cancer, and possible death.

Welding Process Hazards OSHA Welding Regulations
  • Fire
  • Metal splatter
  • Electric shock
  • Explosion hazards
  • Released gases
  • Radiant energy
  • 29 CFR 1910 Subpart Q / General Industry
  • 29 CFR 1926 Subpart J / Construction
  • API RP 54 Section 20 / Hotwork, Welding, and Flame Cutting Operations
  • Three Common Types of Welding

    Arc Welding: Joins two metals by generating an electric arc between a covered metal electrode and the base metal.

    Oxygen and Arc Cutting: The most common metal cutting processes in welding. Severs or removes metal by flame or arc.

  • Oxygen Cutting - Metal is heated by a gas flame and an oxygen jet does the cutting
  • Arc cutting - An intense heat of electric arc melts away the metal
  • Gas Welding: Slower and easier to control than electric arc welding. Utilizes a gas flame over metals until a molten puddle is formed.
    The most popular fuels used with oxygen are:

  • Acetylene
  • Mapp gas
  • Hydrogen
  • General Welding Safety Requirements

    Fire Prevention Safeguards:

  • Fire Hazards should be removed if the welded object cannot be readily moved.
  • Guards should be used if removing fire hazards is not possible.
  • Restrictions apply (no cutting or welding allowed) if none of the above is possible.
  • Special Precautions

  • Protect nearby combustible materials from sparks that might escape through openings in floors or walls.
  • Fire Extinguishers must be ready for instant use.
  • Fire Watch lasting at least 30 min after welding or cutting operations is required if more than a minor fire might develop and if certain combustible materials are present.
  • Floors: Combustible materials must be swept 35 feet away; combustible floors must be wetted or protected (while preventing arc welding shock)
  • Relocation of Combustibles: Combustibles shall be moved 35 feet away or properly protected or shielded.
  • Ducts: Ducts and conveyor systems that might carry sparks must be shut down.
  • Combustible walls must be shielded or guarded.
  • Noncombustible walls, partitions or ceilings (when welded) require opposite-side moving of combustibles or a fire watch.
  • Combustible cover: No welding on certain metal building components having combustible covers or layers.
  • Pipes (or any metal) close enough to combustibles to cause ignition by conduction may not be cut or welded.
  • Used containers must be cleaned of flammable materials or other materials that could release toxic of flammable vapors when heated.
  • Venting and purging is required for hollow spaces or cavities.
  • NOTE: Precautions must be taken during long pauses (during lunch breaks or overnight) in arc welding to prevent accidental contact of electrodes torch valve gas leaks in gas welding.

    Naural and Mechanical Ventilation Health Protection and Ventilation
  • Must not be restricted by screens
  • Sufficient to keep concentrations < PEL
  • Mechanical ventilation required for:
    • Spaces <10,000 feet per welder
    • Rooms with ceilings lower than 16 feet
    • Confined spaces/ areas without natural cross-ventilation
  • General requirements for protecting welders are based on 3 factors:
  • Dimensions of space (especially ceiling height) in which welding is to be done
  • Number of welders
  • Possible evolution of hazardous fumes, gases, or dust according to the metals involved.
  • For more information, download the OSHA Welding, Cutting, and Brazing ppt.