CHST General 4 — Questions and Answers
Question 1: What is the maximum permissible noise exposure for a construction worker at 95 dBA without hearing protection under OSHA standards?
- 8 hours
- 4 hours (Correct answer)
- 2 hours
- 1 hour
Correct answer: 4 hours
OSHA 1926.52 allows a maximum of 4 hours of exposure at 95 dBA without engineering controls or hearing protection in construction.
Question 2: During a toolbox talk, a foreman asks which class of hard hat protects against high-voltage electrical hazards up to 20,000 volts. The correct answer is:
- Class A
- Class B (Correct answer)
- Class C
- Class E
Correct answer: Class B
Class B (Type II) hard hats are tested to protect against high-voltage electrical hazards up to 20,000 volts.
Question 3: A CHST is implementing a hierarchy of controls for a struck-by hazard from overhead crane operations. Which control should be implemented FIRST?
- Require workers to wear hard hats
- Establish exclusion zones under the load path
- Post warning signs near the crane
- Eliminate overhead lifting by using ground-level assembly (Correct answer)
Correct answer: Eliminate overhead lifting by using ground-level assembly
Elimination is the highest and most effective level of the hierarchy of controls, removing the hazard entirely rather than mitigating exposure to it.
Question 4: Which document establishes minimum safety and health program requirements that are widely referenced by safety professionals and used as a framework for construction SMS?
- ANSI/ASSP Z10 (Correct answer)
- NFPA 70E
- OSHA 3132
- ACGIH TLV Handbook
Correct answer: ANSI/ASSP Z10
ANSI/ASSP Z10 is the American national standard for Occupational Health and Safety Management Systems, widely used as a construction SMS framework.
Question 5: Under 29 CFR 1926.502, what is the maximum force a personal fall arrest system must be able to withstand during a fall arrest event?
- 900 pounds
- 1,800 pounds
- 1,800 pounds applied over 6 feet
- 5,000 pounds (Correct answer)
Correct answer: 5,000 pounds
OSHA requires anchorage points for personal fall arrest systems to support at least 5,000 pounds per attached worker.
Question 6: A safety audit of scaffolding reveals planks with a working load of 50 psf. If a scaffold platform is 5 feet wide and 10 feet long, what is the maximum load the platform should support?
- 2,000 lbs
- 2,500 lbs (Correct answer)
- 5,000 lbs
- 500 lbs
Correct answer: 2,500 lbs
50 psf × (5 ft × 10 ft) = 50 × 50 = 2,500 lbs maximum allowable load for this scaffold platform.
Question 7: When conducting a pre-task safety analysis for hot work near flammable materials, a CHST should verify that a fire watch remains on duty for at least how long after welding is complete?
- 15 minutes
- 30 minutes (Correct answer)
- 1 hour
- Until the next shift begins
Correct answer: 30 minutes
NFPA 51B and most hot work permit programs require a fire watch to remain for a minimum of 30 minutes after hot work is completed.
CHST General 4
What is the maximum permissible noise exposure for a construction worker at 95 dBA without hearing protection under OSHA standards?