STSC Hazard Recognition and Risk Assessment 5 — Questions and Answers
Question 1: A supervisor observes that a crane is operating within 20 feet of energized power lines rated at 50 kV. What is the minimum required clearance per OSHA 1926.1408?
- 10 feet
- 15 feet (Correct answer)
- 20 feet
- 25 feet
Correct answer: 15 feet
OSHA 1926.1408 requires a minimum 20-foot clearance for lines over 50 kV, but the base minimum for lines up to 350 kV is 20 feet; for lines up to 50 kV the minimum is 10 feet—but the voltage here triggers 20 feet.
Question 2: Which leading indicator is most useful for identifying hazard recognition gaps on a construction site?
- Number of OSHA recordable injuries in the past year
- Near-miss reporting rate and trends (Correct answer)
- Total workers' compensation costs
- Number of OSHA citations received
Correct answer: Near-miss reporting rate and trends
Near-miss reporting is a leading indicator that reveals hazards before injuries occur, allowing supervisors to act proactively.
Question 3: A worker is applying spray paint in an enclosed scaffold enclosure. Which hazard category does this PRIMARILY represent?
- Struck-by hazard
- Chemical/health hazard with confined space elements (Correct answer)
- Electrical hazard
- Ergonomic hazard
Correct answer: Chemical/health hazard with confined space elements
Spray painting in an enclosed area creates chemical vapor exposure and potential oxygen deficiency, classifying the hazard as chemical/health with confined-space characteristics.
Question 4: During a risk assessment, a supervisor must evaluate the likelihood and severity of a hazard. Which combination represents the HIGHEST risk level?
- Low likelihood / High severity
- High likelihood / Low severity
- High likelihood / High severity (Correct answer)
- Low likelihood / Low severity
Correct answer: High likelihood / High severity
Risk is a product of both likelihood and severity; a hazard that is both highly probable and highly severe demands the most urgent corrective action.
Question 5: A toolbox talk reveals that several workers are unfamiliar with the signs of heat exhaustion on a hot day. What type of hazard does this represent?
- Physical hazard (Correct answer)
- Biological hazard
- Chemical hazard
- Ergonomic hazard
Correct answer: Physical hazard
Heat stress is classified as a physical hazard because it results from environmental energy (thermal) conditions rather than a substance or biological agent.
Question 6: Which action best demonstrates a proactive approach to hazard recognition during the planning phase of a construction project?
- Investigating the root cause of the last project's most costly injury
- Conducting a pre-construction hazard review using project drawings and site conditions (Correct answer)
- Posting emergency contact numbers on the site bulletin board
- Purchasing additional PPE based on the previous project's usage
Correct answer: Conducting a pre-construction hazard review using project drawings and site conditions
Reviewing project drawings and site conditions before work begins allows the team to anticipate and eliminate or control hazards during the design phase, which is the most cost-effective point.
Question 7: According to ANSI/ASSP Z10, which term describes the process of systematically examining a workplace to identify conditions and practices that could cause harm?
- Incident investigation
- Hazard identification (Correct answer)
- Risk control verification
- Management of change
Correct answer: Hazard identification
Hazard identification is the ANSI/ASSP Z10 term for the systematic process of recognizing conditions, behaviors, or events that have the potential to cause harm.
STSC Hazard Recognition and Risk Assessment 5
A supervisor observes that a crane is operating within 20 feet of energized power lines rated at 50 kV.
What is the minimum required clearance per OSHA 1926.1408?