AWS Welder Safety & Compliance 3 — Questions and Answers
Question 1: What is the primary purpose of a fire watch during and after welding operations?
- To monitor the welder's technique for quality assurance
- To detect and extinguish fires that may start from sparks or slag (Correct answer)
- To ensure the welding machine does not overheat
- To verify that the shielding gas flow rate is correct
Correct answer: To detect and extinguish fires that may start from sparks or slag
A fire watch monitors the work area for fires caused by sparks or slag during welding and for a minimum of 30 minutes after hot work ends, as required by OSHA 1910.252.
Question 2: Which welding lens shade is generally recommended for SMAW (stick) welding at 200–250 amperes per ANSI Z87.1?
- Shade 8
- Shade 10
- Shade 12 (Correct answer)
- Shade 14
Correct answer: Shade 12
ANSI Z87.1 and AWS F2.2 recommend shade 12 for SMAW operations in the 200–250 ampere range to adequately protect against arc radiation.
Question 3: Which of the following best describes the lockout/tagout (LOTO) requirement before performing maintenance on a welding machine?
- Turn the power switch off and place a warning sign nearby
- De-energize the machine, lock the energy source, and verify zero energy state (Correct answer)
- Unplug the machine and inform a supervisor verbally
- Switch the machine to standby mode before starting work
Correct answer: De-energize the machine, lock the energy source, and verify zero energy state
OSHA 29 CFR 1910.147 requires that energy sources be isolated, locked out with a personal lock, and verified to be in a zero-energy state before any maintenance or servicing begins.
Question 4: Hexavalent chromium (Cr(VI)) is a known carcinogen produced when welding which base metals?
- Carbon steel and cast iron
- Aluminum and magnesium alloys
- Stainless steel and chrome-containing alloys (Correct answer)
- Copper and brass
Correct answer: Stainless steel and chrome-containing alloys
Welding stainless steel and other chromium-containing alloys generates hexavalent chromium fumes, which OSHA regulates with a permissible exposure limit (PEL) of 5 µg/m³ as an 8-hour TWA.
Question 5: What minimum shade number does OSHA require for filter lenses used in oxygen-fuel gas cutting operations with heavy cutting (tip size 6 and above)?
- Shade 3
- Shade 5
- Shade 6 (Correct answer)
- Shade 8
Correct answer: Shade 6
OSHA Table E-2 in 1910.252 recommends shade 6 as the minimum for heavy oxygen-fuel gas cutting operations using large tip sizes.
Question 6: A welder notices a hissing sound and frost forming on an oxygen cylinder valve. What is the correct immediate action?
- Tighten the packing nut with a wrench while the valve is open
- Close the valve immediately, remove the cylinder to open air, and notify the supplier (Correct answer)
- Wrap the valve with duct tape to stop the leak
- Continue welding but reduce oxygen flow to minimize the leak
Correct answer: Close the valve immediately, remove the cylinder to open air, and notify the supplier
A leaking oxygen cylinder must have its valve closed immediately; the cylinder should be moved outdoors away from ignition sources and the gas supplier notified — never attempt to repair a leaking cylinder valve.
Question 7: Under AWS D1.1 safety provisions, what minimum distance must be maintained between gas cylinders and actual welding or cutting operations?
- 5 feet
- 10 feet (Correct answer)
- 20 feet
- 35 feet
Correct answer: 10 feet
AWS and OSHA 1910.253 require that fuel gas and oxygen cylinders be kept at least 20 feet from welding operations or separated by a 5-foot-high noncombustible barrier with a fire resistance rating of at least 30 minutes.
AWS Welder Safety & Compliance 3
What is the primary purpose of a fire watch during and after welding operations?