CHST CHST - Construction Health and Safety Technician Health Hazards and PPE Questions and Answers 5 — Questions and Answers
Question 1: A concrete cutter is operating a gas-powered saw in a partially enclosed trench. Which hazard is of GREATEST immediate concern?
- Vibration white finger from saw handle
- Carbon monoxide accumulation from engine exhaust (Correct answer)
- Noise-induced hearing loss from saw operation
- Hand-arm vibration syndrome
Correct answer: Carbon monoxide accumulation from engine exhaust
Gas-powered equipment in confined or partially enclosed spaces rapidly generates carbon monoxide, which can reach IDLH levels (1,200 ppm) before the operator notices symptoms.
Question 2: Under the OSHA Heat Illness Prevention guidance, which physiological sign indicates heat stroke rather than heat exhaustion?
- Heavy sweating and pale, moist skin
- Muscle cramps and weakness
- Altered mental status and hot, dry or wet skin (Correct answer)
- Nausea and headache with normal mentation
Correct answer: Altered mental status and hot, dry or wet skin
Heat stroke, a medical emergency, is distinguished by central nervous system dysfunction (confusion, altered consciousness) and core body temperature above 104°F (40°C).
Question 3: A construction employer's written exposure control plan for silica must include which element under 29 CFR 1926.1153?
- A list of all silica-containing products on the project
- Description of tasks involving silica exposure and the engineering and work practice controls used (Correct answer)
- Workers' personal medical records and PLHCP evaluations
- Annual air monitoring results for each individual worker
Correct answer: Description of tasks involving silica exposure and the engineering and work practice controls used
The written exposure control plan must describe each task that involves silica exposure, the engineering controls, work practices, and respiratory protection used for each task.
Question 4: When selecting chemical protective clothing (CPC) for a worker handling a highly corrosive acid, which factor is MOST important to evaluate first?
- Comfort and range of motion for the worker
- Breakthrough time of the chemical through the material (Correct answer)
- Cost and availability of replacement garments
- Color coding for site identification purposes
Correct answer: Breakthrough time of the chemical through the material
Breakthrough time — the time for a chemical to permeate through the CPC material at a detectable level — is the primary criterion because it determines the duration of safe use.
Question 5: A roofer experiences tingling and numbness in fingers after long-term use of vibrating equipment. This condition is BEST described as:
- Carpal tunnel syndrome caused by repetitive flexion
- Hand-arm vibration syndrome (HAVS) including vascular and neurological effects (Correct answer)
- Contact dermatitis from roofing adhesives
- Raynaud's disease unrelated to occupational exposure
Correct answer: Hand-arm vibration syndrome (HAVS) including vascular and neurological effects
Hand-arm vibration syndrome (HAVS) results from prolonged exposure to hand-transmitted vibration, causing both vascular (vibration white finger) and neurological symptoms like tingling and numbness.
Question 6: Which respirator filter designation is required to protect against oil-based aerosols in addition to particulates?
- N-series filters (e.g., N95)
- R-series filters (e.g., R95)
- P-series filters (e.g., P100) (Correct answer)
- HE-series filters for powered air purifying
Correct answer: P-series filters (e.g., P100)
P-series filters (P95, P100) are strongly resistant to oil and rated for use in oil aerosol environments; R-series offer limited oil resistance, while N-series have none.
Question 7: What is the OSHA permissible exposure limit (PEL) for benzene in construction as an 8-hour TWA?
- 0.5 ppm
- 1 ppm (Correct answer)
- 5 ppm
- 10 ppm
Correct answer: 1 ppm
OSHA's PEL for benzene is 1 ppm as an 8-hour TWA (29 CFR 1910.1028, adopted by construction), with an action level of 0.5 ppm.
CHST CHST - Construction Health and Safety Technician Health Hazards and PPE Questions and Answers 5
A concrete cutter is operating a gas-powered saw in a partially enclosed trench.
Which hazard is of GREATEST immediate concern?