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Safety Protocol 001: General Welding Safety — Electrical, Thermal, Radiation & Respiratory Hazards

Protocol ID: U6M1-SAFE-001 Context: Comprehensive safety protocol covering all hazards common to MIG and TIG welding operations in a makerspace environment Hazard Level: Very High — Arc welding involves lethal voltage, extreme temperatures, intense radiation, toxic fumes, and fire risk

Potential Hazards

Electrical Hazards

  • Welding circuit voltage: MIG welders produce 18-34V during welding; open circuit voltage (OCV) reaches 60-80V DC. TIG welders: 10-20V during welding, OCV up to 80V DC. AC TIG (for aluminum) poses higher shock risk due to alternating polarity
  • Secondary shock: Contact with the electrode or work while the machine is on. Wet conditions dramatically increase risk. Risk is highest during setup and electrode changes

Thermal Hazards

  • Arc temperature: 6,000-10,000°F at the arc center
  • Molten metal and spatter: MIG produces significant spatter; both processes eject molten metal
  • Hot workpiece: Metal reaches 500-1,500°F near the weld zone and retains heat for minutes
  • Fire: Sparks and spatter can travel 20+ feet and ignite combustibles

Radiation Hazards

  • UV radiation: The welding arc produces intense UV-A, UV-B, and UV-C radiation causing arc eye (photokeratitis) and skin burns
  • Infrared radiation: Causes thermal eye injury and skin burns with prolonged exposure
  • Blue light hazard: High-intensity visible light can cause retinal damage

Respiratory Hazards

  • Welding fumes: All welding produces metal fumes (iron oxide, manganese, and others depending on base/filler metal)
  • Hexavalent chromium: Generated when welding stainless steel — OSHA-regulated carcinogen
  • Manganese: Present in most steel welding fumes — neurological toxin at chronic exposure levels
  • Ozone: Generated by UV radiation from the arc — respiratory irritant
  • Shielding gas displacement: In enclosed spaces, argon (heavier than air) can displace oxygen, creating asphyxiation risk

Noise Hazards

  • MIG welding: 80-95 dB (especially short-circuit transfer)
  • Grinding (associated with welding): 95-110 dB

Required Precautions & Procedures

Before Welding

  1. Inspect welding machine, cables, torch, and ground clamp for damage
  2. Verify shielding gas type and flow rate for the material being welded
  3. Clean the joint area to bright metal — remove paint, oil, rust, and mill scale
  4. Clear combustibles within 35 feet (NFPA 51B)
  5. Ensure adequate ventilation — local exhaust (fume extractor) positioned 4-6" from the weld zone
  6. Verify fire extinguisher location (within 15 feet)
  7. Ensure all personnel have PPE or are behind welding screens

During Welding

  1. Never weld without proper eye protection — welding helmet with correct shade
  2. Keep all skin covered — UV burns exposed skin in seconds
  3. Never look at the arc without a welding helmet, even briefly
  4. Do not touch the electrode, wire, or workpiece with bare skin while the machine is on
  5. Ensure the work clamp makes solid contact with the workpiece
  6. Never weld in a confined space without forced ventilation and gas monitoring
  7. Never weld on containers that held flammables without proper purging certification

After Welding

  1. Mark hot metal with "HOT" — use soapstone or heat marker
  2. Allow workpiece to cool naturally — do not quench unless instructed
  3. Turn off the welding machine at the power switch
  4. Close the shielding gas cylinder valve
  5. Maintain fire watch for 30 minutes
  6. Store the torch/gun securely — do not leave hanging or on the floor

Emergency Response

  1. Electrical shock: Do NOT touch victim. Disconnect power at main switch. Call 911. CPR/AED if needed
  2. Burns: Cool with running water 20 minutes. Do NOT apply ice. Seek medical attention for 2nd/3rd degree
  3. Arc eye: Move to dim area. Cool compresses on closed eyes. Do NOT rub. Seek medical attention (delayed onset 6-12 hrs)
  4. Fire: E-stop welder. Use ABC/CO₂ extinguisher if small. Evacuate if growing. Call 911
  5. Fume inhalation: Move to fresh air. Call 911 if breathing difficulty. Provide material/filler information to responders

PPE Requirements

PPE Item Specification Required When
Welding helmet Shade 10-12 for MIG; Shade 8-10 for TIG (lower amp); auto-darkening recommended All arc welding
Safety glasses ANSI Z87.1, under helmet Always in welding area
FR jacket/long sleeves Leather or ASTM F1506 rated All welding operations
Leather welding gloves MIG: gauntlet style; TIG: lightweight leather (dexterity) All welding operations
Leather boots Steel/composite toe, 8"+ shaft Always in shop
Hearing protection NRR 25+ MIG welding and all grinding
Respirator P100 half-face minimum; P100+OV for stainless All welding operations
Welding cap FR fabric, brim protects ears and neck All welding operations
No synthetic clothing Melts into skin from sparks/radiation Never wear near arc welding

Last Updated: 2026-03-19