NCCER Core Construction Site Safety 3 — Questions and Answers
Question 1: At what noise level (8-hour TWA) does OSHA require a hearing conservation program?
- 75 dB
- 80 dB
- 85 dB (Correct answer)
- 90 dB
Correct answer: 85 dB
OSHA requires a hearing conservation program at 85 dB TWA.
OSHA distinguishes between the Action Level (85 dB) and the Permissible Exposure Limit (90 dB). At 85 dB, employers must implement noise monitoring, audiometric testing, hearing protectors, and training. For every 5 dB increase above 90, permissible exposure time is halved.
Question 2: What is required before entering a confined space?
- Verbal approval from a coworker
- A confined space entry permit with atmospheric testing (Correct answer)
- Hard hat and safety glasses only
- Written approval from the building owner
Correct answer: A confined space entry permit with atmospheric testing
A permit with atmospheric testing for oxygen, flammable gases, and toxic substances is required.
OSHA 29 CFR 1926.1201-1213 requires a written permit documenting atmospheric testing (oxygen 19.5-23.5%, flammables below 10% LEL, toxics below PEL), ventilation, communication, and rescue procedures. An attendant must remain outside at all times.
Question 3: What is the minimum width for a construction site walkway?
- 18 inches
- 20 inches (Correct answer)
- 24 inches
- 28 inches
Correct answer: 20 inches
Construction walkways must be at least 20 inches wide.
OSHA requires walkways to be at least 20 inches wide for single-person passage. When elevated with drops of 6 feet or more, guardrails are required (42 inches high with mid-rail at 21 inches). Surfaces must be slip-resistant.
Question 4: What type of barricade tape indicates an immediate danger zone?
- Yellow caution tape
- Red danger tape (Correct answer)
- Orange safety tape
- White boundary tape
Correct answer: Red danger tape
Red danger tape indicates immediate hazard — do not cross without authorization.
Red DANGER tape marks areas with hazards that could cause death or serious injury — only authorized personnel may enter. Yellow CAUTION tape marks areas with potential minor to moderate hazards. These follow OSHA's sign standards in 29 CFR 1926.200.
Question 5: How should compressed gas cylinders be stored?
- Laying flat on the ground
- Upright, secured with chains, caps in place when not in use (Correct answer)
- Stacked on pallets three high
- In direct sunlight
Correct answer: Upright, secured with chains, caps in place when not in use
Cylinders must be stored upright, secured to prevent falling, with valve caps in place.
Store upright and secured with chains or straps. Valve caps must be in place when not connected. Store oxygen and fuel gas at least 20 feet apart or with a 5-foot fire-resistant barrier. A damaged valve can turn a cylinder into a lethal projectile.
Question 6: What is the purpose of a toolbox talk at the start of a shift?
- To assign work tasks
- To discuss specific safety topics and hazards for the day's work (Correct answer)
- To review the project budget
- To collect timesheets
Correct answer: To discuss specific safety topics and hazards for the day's work
Toolbox talks are short safety meetings addressing specific hazards relevant to planned activities.
Toolbox talks are 5-15 minute meetings covering safety topics relevant to the day's work. They provide an opportunity to review the Job Hazard Analysis, discuss near-misses, remind of PPE requirements, and allow workers to raise safety concerns.
NCCER Core Construction Site Safety 3
At what noise level (8-hour TWA) does OSHA require a hearing conservation program?