CFB Safety & Compliance Standards 2 — Questions and Answers
Question 1: Which OSHA standard specifically governs excavation and trenching safety on field construction sites?
- 29 CFR 1926.650-.652 (Correct answer)
- 29 CFR 1910.147
- 29 CFR 1926.502
- 29 CFR 1910.303
Correct answer: 29 CFR 1926.650-.652
OSHA 29 CFR 1926.650-.652 (Subpart P) covers excavations, trenching, and shoring requirements for construction sites.
Question 2: A field builder notices a trench is 6 feet deep with no protective system in place. What is the correct immediate action?
- Stop work and evacuate workers from the trench (Correct answer)
- Add spoil piles closer to the trench edge for stability
- Continue work if the soil appears stable
- Install a ladder and proceed with caution
Correct answer: Stop work and evacuate workers from the trench
OSHA requires a protective system (sloping, shoring, or shielding) for any trench 5 feet or deeper; workers must be evacuated until it is in place.
Question 3: What does the term 'competent person' mean in the context of OSHA excavation standards?
- Someone capable of identifying hazards and authorized to take corrective action (Correct answer)
- Any worker with more than one year of field experience
- A licensed professional engineer on staff
- A worker who has completed a 10-hour OSHA course
Correct answer: Someone capable of identifying hazards and authorized to take corrective action
OSHA defines a competent person as one who can identify existing and predictable hazards and has authority to eliminate them.
Question 4: Under NFPA 70E, an arc flash boundary is established to protect workers from which hazard?
- Incident energy that could cause a second-degree burn (Correct answer)
- Excessive noise levels near electrical panels
- Chemical splash from battery acid
- Ground fault current during installation
Correct answer: Incident energy that could cause a second-degree burn
The arc flash boundary marks the distance at which incident energy equals 1.2 cal/cm², the threshold for a curable second-degree burn.
Question 5: Which document must be completed before workers begin hot work (welding/cutting) on a field construction project?
- Hot work permit (Correct answer)
- Confined space entry permit
- Lockout/tagout log
- Material safety data request
Correct answer: Hot work permit
A hot work permit authorizes and controls ignition-source activities, ensuring fire watch and extinguisher requirements are met beforehand.
Question 6: What is the minimum safe approach distance for an unqualified worker near an energized overhead power line operating at 50 kV?
- 10 feet (Correct answer)
- 3 feet
- 6 feet
- 20 feet
Correct answer: 10 feet
OSHA 1926.1408 requires a 10-foot minimum clearance for voltages up to 50 kV for unqualified workers.
Question 7: A field builder discovers a spill of a hazardous chemical on site. According to HAZCOM standards, where should they first look for handling instructions?
- The Safety Data Sheet (SDS) for that chemical (Correct answer)
- The project superintendent's daily log
- The local fire department hotline
- The chemical container label color code
Correct answer: The Safety Data Sheet (SDS) for that chemical
OSHA's Hazard Communication Standard (29 CFR 1910.1200) requires SDS documents to be accessible on-site for every hazardous chemical in use.
CFB Safety & Compliance Standards 2
Which OSHA standard specifically governs excavation and trenching safety on field construction sites?