Electric arc welding creates three simultaneous hazards that non-welders often underestimate: a 35-ampere arc that can electrocute at voltages as low as 50V, ultraviolet radiation that causes "arc eye" (photokeratitis) in 30 seconds of unprotected exposure, and infrared radiation that causes cataract formation with chronic exposure. Every worker in proximity to arc welding must understand all three hazards.

• Never weld in wet or damp conditions — water lowers skin resistance to near zero and dramatically increases electrocution risk
• Never allow welding cable insulation to contact hot metal, sharp edges, or areas where vehicles travel
• Keep the electrode holder dry and the cable connected — do not lay a hot electrode holder on the work table
• Ground return connection: properly placed to ensure current returns through the cable, not through pipes, conduits, or building structure
• At end of shift: disconnect the electrode holder from the machine before leaving — prevents accidental circuit closure

• UV radiation from the arc causes "arc eye" — identical to a severe sunburn on the cornea. Develops 6–12 hours after exposure; extremely painful; requires medical treatment
• Shade requirement: minimum Shade 10 lens for SMAW (stick) welding, Shade 9 minimum for TIG
• Screen/flash barriers required when welding in multi-worker areas — nearby workers cannot see the arc directly
• Protective clothing: dry leather gloves, flame-resistant sleeves, and a welding jacket. Cotton or synthetic clothing can ignite from arc spatter