Welding Safety and Health
This domain tests the safety decisions a welder makes before, during, and after hot work: PPE selection, fume and ventilation control, electrical protection, compressed-gas handling, and fire prevention. NCCER-style items often ask for the specific control, not a general warning.
PPE and exposure
Wear ANSI Z87.1 eye protection under the helmet. Select the arc filter by process and current; SMAW at 140 A calls for shade 10, and oxyfuel cutting generally calls for a much lighter shade (about 3–5). Leathers, gauntlets, and flame-resistant clothing cover exposed skin. Keep your head out of the fume plume and use local exhaust ventilation; welding galvanized steel can produce zinc oxide fume and metal fume fever, so remove coating from the weld zone and add respiratory protection when ventilation is inadequate. Never use oxygen to blow dust off clothing.
Electrical and gas
Insulate the electrode holder, replace damaged cable, and keep gloves dry. The work lead must clamp to the workpiece, not to a pipeline or structural member that could carry current. Store cylinders upright with caps on, separate oxygen from fuel gas by 20 ft or a 5 ft noncombustible barrier, and keep oil and grease away from oxygen fittings. Acetylene pressure must not exceed 15 psig. Use flashback arrestors and leak-test with soap solution, never a flame.
Fire prevention
Hot work requires a permit, removal or protection of combustibles within 35 ft, and a fire watch where needed. The watch continues at least 30 minutes after the arc stops.
Worked example: A candidate is asked to set up SMAW at 140 A on galvanized plate in a shop bay with nearby cardboard. Reasoning: choose shade 10 for the current; move or shield the cardboard to the 35 ft rule; grind the zinc from the joint area; use LEV and a respirator if exposure remains; assign a fire watch for the work and 30 minutes after.
Traps: Sunglasses are not a substitute for a filter lens; a fire watch does not end when the arc stops; oxygen is not a cleaning gas; cylinders are not laid down for storage.