CHST - Construction Health and Safety Technician Health Hazards and PPE Questions and Answers Flashcards

A concrete cutter is operating a gas-powered saw in a partially enclosed trench. Which hazard is of GREATEST immediate concern?

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.

Under the OSHA Heat Illness Prevention guidance, which physiological sign indicates heat stroke rather than heat exhaustion?

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).

A construction employer's written exposure control plan for silica must include which element under 29 CFR 1926.1153?

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.

When selecting chemical protective clothing (CPC) for a worker handling a highly corrosive acid, which factor is MOST important to evaluate first?

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.

A roofer experiences tingling and numbness in fingers after long-term use of vibrating equipment. This condition is BEST described as:

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.

Which respirator filter designation is required to protect against oil-based aerosols in addition to particulates?

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.

What is the OSHA permissible exposure limit (PEL) for benzene in construction as an 8-hour TWA?

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.