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Safety Protocol 001: TIG Welding Operation Safety

Protocol ID: U6M3-SAFE-001 Context: Safety procedures specific to TIG (GTAW) welding including tungsten hazards, high-frequency start risks, foot pedal ergonomics, and argon asphyxiation Hazard Level: Very High — Arc welding with non-consumable electrode, high-frequency starting, and concentrated UV radiation

Potential Hazards

TIG-Specific Hazards

  • High-frequency (HF) arc starting: Some TIG welders use HF to initiate the arc. HF generates RF radiation that can interfere with pacemakers and other medical devices. Operators with pacemakers must NOT use HF-start machines — use lift-arc or scratch-start instead
  • Tungsten electrode hazards: Thoriated tungsten contains radioactive thorium. Grinding produces contaminated dust. Broken tungsten fragments are sharp and can puncture skin. Hot tungsten (after welding) can cause point burns
  • Argon asphyxiation: Pure argon is heavier than air (density 1.4× air) and displaces oxygen at floor level. In enclosed welding booths, pits, or confined spaces, argon accumulation can reduce oxygen below safe levels (19.5% minimum) without any warning odor or sensation
  • AC welding shock risk: AC TIG welding for aluminum produces alternating polarity, which does not allow muscle contraction in one direction — this means the victim may be unable to release the conductor, similar to AC household current
  • Concentrated UV: TIG arcs, especially at higher amperage, produce more concentrated UV radiation than MIG arcs due to the focused arc from the tungsten point

General Arc Welding Hazards

  • Electrical shock (60-80V OCV)
  • Burns from arc, spatter, and hot workpiece
  • Metal fumes (see material-specific notes)
  • Fire from sparks
  • Noise (lower than MIG but still requires protection during grinding)

Required Precautions & Procedures

Before TIG Welding

  1. Inspect the torch: check for cracked cups, damaged collet, secure cable connections
  2. Verify the tungsten is properly ground and the correct type for the application
  3. If grinding tungsten: use the DEDICATED wheel only, wear safety glasses and dust mask, use local exhaust if available
  4. Check the gas system: cylinder secure, regulator functioning, hose intact
  5. Set the post-flow timer: 1 second per 10 amps minimum
  6. If using HF start: verify no personnel with pacemakers are in the area. Post a warning sign: "HIGH FREQUENCY IN USE — PACEMAKER HAZARD"
  7. Ensure adequate ventilation — especially for enclosed booths. Argon accumulation at floor level is invisible and odorless

During TIG Welding

  1. Never touch the tungsten while the machine is on — even without an arc, OCV is present
  2. If the tungsten contacts the pool and contaminates: stop welding, turn off the machine, remove and re-grind the tungsten. Do NOT continue with a contaminated tungsten — it will create an unstable arc and contaminate the weld
  3. Keep the filler rod within the gas shield when not dipping — an oxidized rod tip contaminates the next dip
  4. Rest the filler rod on a fire-resistant surface, NOT your leg or the table clamp
  5. The foot pedal cord must be clear of wheels and obstacles — tripping on the cord while welding causes tungsten contamination and arc flash
  6. Monitor for signs of argon displacement: lightheadedness, shortness of breath. If symptoms occur, stop welding and move to fresh air immediately
  7. Do NOT drape the torch over your shoulder or hang it from the machine with the gas flowing — argon will pool around your face

After TIG Welding

  1. Maintain post-flow — hold the torch over the weld until gas stops flowing
  2. Set the torch down on a heat-resistant surface (the cup and tungsten are hot)
  3. Close the gas cylinder valve
  4. Turn off the machine
  5. If thoriated tungsten was ground: empty the grinding wheel's dust tray into a sealed bag for proper disposal
  6. Mark all hot metal "HOT"
  7. Fire watch: 30 minutes

Emergency Response

  1. Argon asphyxiation: If a person collapses in a welding booth — do NOT enter without ensuring ventilation. Open booth curtains/doors first. Move the person to fresh air. Call 911. Begin CPR if not breathing. Even brief oxygen deprivation can be fatal
  2. Tungsten puncture: Remove the fragment if superficial. For deep punctures, do not remove — seek medical attention. Clean wound with antiseptic
  3. Pacemaker interference: If a person with a pacemaker reports symptoms (dizziness, irregular heartbeat) near an HF TIG machine: immediately turn off the machine, move the person away, call 911
  4. All other emergencies: See U6M1-SAFE-001 for electrical shock, burns, arc eye, fire, and fume exposure responses

PPE Requirements

PPE Item Specification Required When
Welding helmet Shade 8-10 (<100A), Shade 10-12 (100A+) All TIG welding
Safety glasses ANSI Z87.1, under helmet Always in welding area
FR jacket/shirt Leather or ASTM F1506, long sleeves All TIG welding
TIG gloves Thin leather (goatskin/deerskin) for dexterity All TIG welding
Leather boots Steel/composite toe, 8"+ Always in shop
Respirator P100 half-face minimum; P100+OV for stainless All welding
Welding cap FR fabric All welding
Dust mask N95 minimum During tungsten grinding
No synthetic clothing Melts from UV radiation and sparks Never near arc welding

Last Updated: 2026-03-19