PC Plumber Safety & Code Compliance 2 — Questions and Answers
Question 1: When working in a confined space with a potential for oxygen deficiency, what is the minimum acceptable oxygen level before entry is permitted?
- 16%
- 19.5% (Correct answer)
- 21%
- 23.5%
Correct answer: 19.5%
OSHA requires a minimum of 19.5% oxygen in confined spaces before workers may enter without supplied-air respirators.
Question 2: According to the IPC, what is the minimum distance a cleanout must be located from a wall or obstruction to allow rodding access?
- 6 inches
- 12 inches
- 18 inches (Correct answer)
- 24 inches
Correct answer: 18 inches
The IPC requires cleanouts to be installed with at least 18 inches of clearance in front for rodding equipment access.
Question 3: A plumber discovers asbestos pipe insulation while roughing in new supply lines. What is the correct immediate action?
- Remove it carefully using wet methods
- Continue work and report at end of day
- Stop work, leave the area undisturbed, and notify supervisor (Correct answer)
- Cover it with new insulation and proceed
Correct answer: Stop work, leave the area undisturbed, and notify supervisor
Disturbing asbestos-containing materials requires stopping all work immediately and reporting to a supervisor so licensed abatement can be arranged.
Question 4: Under the UPC, what is the required air gap between the flood level rim of a fixture and the lowest point of a potable water supply outlet?
- 1 pipe diameter
- 2 pipe diameters (minimum 1 inch) (Correct answer)
- 3 pipe diameters
- 4 pipe diameters
Correct answer: 2 pipe diameters (minimum 1 inch)
The UPC requires an air gap of at least twice the inside diameter of the supply pipe, with a minimum of 1 inch, to prevent backflow contamination.
Question 5: Which OSHA standard specifically governs excavation and trenching safety for plumbers working in trenches deeper than 5 feet?
- 29 CFR 1926.50
- 29 CFR 1926.652 (Correct answer)
- 29 CFR 1910.147
- 29 CFR 1926.100
Correct answer: 29 CFR 1926.652
29 CFR 1926.652 (Subpart P) governs excavation and trenching safety, requiring protective systems for trenches 5 feet or deeper.
Question 6: What is the maximum allowable water pressure at a building's plumbing fixtures according to most plumbing codes?
- 60 psi
- 80 psi (Correct answer)
- 100 psi
- 120 psi
Correct answer: 80 psi
Most plumbing codes, including the IPC and UPC, set a maximum static water pressure of 80 psi at any fixture to protect system components.
Question 7: When soldering copper pipe joints in a wall cavity, which fire safety measure is required by OSHA and fire codes?
- Use only low-temp solder below 300°F
- Place a fire-resistant shield behind the work area (Correct answer)
- Apply water to surrounding framing before soldering
- Only solder joints in open areas, never in cavities
Correct answer: Place a fire-resistant shield behind the work area
A fire-resistant shield or heat-resistant cloth must be placed behind the pipe to protect combustible framing materials during soldering.
PC Plumber Safety & Code Compliance 2
When working in a confined space with a potential for oxygen deficiency, what is the minimum acceptable oxygen level before entry is permitted?