Welding Safety

Welding Safety - OSHA Welding 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 are extremely dangerous because they do not always carry an odor and are submicron in size making them invisible to the human eye. 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.

OSHA Welding Regulations

29 CFR 1910 Subpart Q 29 CFR 1926 Subpart J
§ 1910.252 General Requirements
§ 1910.253 Oxygen Fuel Gas Welding & Cutting
§ 1910.254 Arc Welding and Cutting
§ 1910.255 Resistance Welding

§ 1926.350 Gas welding and cutting
§ 1926.351 Arc Welding & Cutting
§ 1926.352 Fire Prevention
§ 1926.353 Ventilation and Protection in Welding, Cutting, and Heating
§ 1926.354 Welding, Cutting, and Heating in Way of Preservative Coatings

Grinding and Deburring

29 CFR 1910 Subpart O - Machinery and Machine Guarding

§ 1910.212 General Requirements for All Machines
§ 1910.213 Woodworking Machinery Requirements
§ 1910.215 Abrasive Wheel Machinery

§ 1910.216 Mills and Calenders in The Rubber and Plastics industries
§ 1910.217 Mechanical Power Presses
§ 1910.218 Forging Machines
§ 1910.219 Mechanical Power-Transmission Apparatus

Laser and Plasma Cutting

29 CFR 1910 Subpart Z

§ 1910.1000 Air Contaminants
§ 1910.1026 Chromium (VI)
§ 1926.353 Ventilation and Protection in Welding, Cutting, and Heating
OSHA Exposure Limits and Health Effects of Manganese Fume (as Mn)

Most Common Types of Welding

While there are over thirty types of welding processes, the most commonly performed are MIG, TIG, Stick, and Arc. Gas metal arc welding, also known as GMAW or MIG, continually feeds solid wire welding rod (electrode) through a welding gun. An electric arc is formed between the electrode and the base material to heat the material causing it to melt and join.

MIG welding is typically used for auto body fabrication and small to large manufacturing and can be used to weld a range of metal alloys including stainless steel, magnesium, carbon steel, silicon bronze, copper, nickel, and aluminum.

GTAW, gas tungsten arc welding or TIG utilizes a non-consumable tungsten electrode to heat the base material creating a molten weld puddle. A no filler metal weld is created by melting two pieces of metal together. An external filler rod can be added to the molten puddle to create a weld bead and enhance mechanical properties. TIG welding is most often used for aerospace welding, motorcycles, bikes, and pipe systems.

Stick welding, also known as shielded metal arc welding or SMAW, is generally used for heavy equipment repair, construction, steel erection, and pipeline welding.

During stick welding, the energized circuit and the tip of the electrode touch the metal workpiece and is taken back but remains in close contact to create an electric arc across the gap. SMAW reaches a temperature of 6500°F to melt the base metal and the electrode to develop a weld.

Arc, FCAW or flux-cored arc welding, is similar to MIG because it uses a continuously fed electrode but it differs by using a tubular wire filled with flux instead of a solid wire. FCAW can be split into self-shielded and dual shield where self-shielded doesn't use an external gas shield and instead uses the flux to shield the molten puddle. Dual shield utilizes the flux and an external shielding gas to protect the molten weld puddle. Arc welding is used for steel erection, thick materials, and heavy equipment construction and repair.

It's critical that employers understand and protect welders from welding process hazards. Regardless of what welding process or processes are performed in your facility, without proper fume exhaust extraction solutions you are at risk of fire, metal splatter, electric shock, explosions hazards, released gases, and radiant energy.

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.