AWS Safety & Welding Standards 3 — Questions and Answers
Question 1: What does the term 'lockout/tagout' (LOTO) refer to in a welding shop context?
- A method of securing electrode holders when not in use
- A procedure to de-energize and secure equipment before maintenance (Correct answer)
- A process for locking filler metal storage cabinets
- A technique for securing workpieces during tack welding
Correct answer: A procedure to de-energize and secure equipment before maintenance
LOTO (OSHA 29 CFR 1910.147) is an energy control procedure that de-energizes and physically locks equipment before maintenance to prevent accidental startup.
Question 2: According to AWS Z49.1, a 'hot work permit' is required when:
- Welding outdoors in temperatures above 90°F
- Performing welding in areas with fire or explosion hazards (Correct answer)
- Using preheating above 300°F on base metal
- Operating plasma cutting equipment above 100 amps
Correct answer: Performing welding in areas with fire or explosion hazards
AWS Z49.1 requires a hot work permit before conducting welding or cutting in locations where fire or explosion risks are present.
Question 3: Which AWS standard governs the qualification of welding procedures and welders for piping and tubing?
- AWS D1.1
- AWS D1.6
- AWS B2.1 (Correct answer)
- AWS A5.18
Correct answer: AWS B2.1
AWS B2.1 covers the specification for welding procedure and performance qualification applicable to a broad range of base metals including piping.
Question 4: When storing compressed gas cylinders in a welding area, AWS and OSHA require that oxygen and fuel gas cylinders be separated by at least:
- 5 feet
- 10 feet or a 5-foot fire wall (Correct answer)
- 20 feet
- 25 feet or a 10-foot fire wall
Correct answer: 10 feet or a 5-foot fire wall
OSHA 1910.253 requires oxygen and fuel gas cylinders in storage to be separated by at least 20 feet or by a noncombustible barrier at least 5 feet high with a fire rating of 0.5 hour.
Question 5: AWS standards classify welding fumes containing hexavalent chromium (Cr VI) as particularly hazardous because Cr VI is:
- Highly flammable when airborne
- A known human carcinogen (Correct answer)
- Acutely toxic to the cardiovascular system
- A strong skin sensitizer only
Correct answer: A known human carcinogen
Hexavalent chromium is classified as a known human carcinogen by IARC and OSHA, requiring strict exposure controls during stainless steel welding.
Question 6: What is the purpose of a 'fire watch' as defined by AWS Z49.1?
- Monitor welding arc stability during operations
- Observe the work area during and after welding for ignition sources (Correct answer)
- Inspect gas regulators for leaks before welding
- Record preheat temperatures throughout the weld pass
Correct answer: Observe the work area during and after welding for ignition sources
A fire watch person monitors the work area during welding and for at least 30 minutes afterward to detect and extinguish any fires that may start.
Question 7: Which type of respirator is required when welding on lead-containing base metals in an enclosed space?
- N95 filtering facepiece
- Half-face air-purifying respirator with P100 filters
- Supplied-air respirator (SAR) or SCBA (Correct answer)
- Powered air-purifying respirator (PAPR) with N95 filters
Correct answer: Supplied-air respirator (SAR) or SCBA
Lead fume in enclosed spaces can quickly exceed safe levels; a supplied-air respirator or SCBA ensures the welder receives uncontaminated breathing air.
AWS Safety & Welding Standards 3
What does the term 'lockout/tagout' (LOTO) refer to in a welding shop context?