Construction Focus Four Hazards
The four categories
The Focus Four - falls, struck-by, caught-in/between, and electrocution - account for the majority of construction fatalities, so expect several questions built around telling them apart.
Falls
Fall protection is triggered at 6 feet in construction, 10 feet on scaffolds, and 4 feet in general industry. Ladders must extend 3 feet above the landing and be set at a 4:1 angle. Guardrail systems, personal fall arrest, and hole covers all qualify. The trap is choosing a generic "fall protection" answer when the question asks which system suits a specific task or surface.
Struck-by versus caught-in/between
Struck-by means impact from a falling, flying, swinging, or rolling object. Caught-in/between means being squeezed, crushed, or pinned - trench cave-ins, machinery entanglement, being caught between equipment and a wall. Examiners deliberately swap these two labels.
Electrocution
The crane rule requires 10 feet of clearance from energized lines up to 50 kV and 20 feet above that, with a spotter or insulating link unless the utility de-energizes and grounds the line.
Worked example
A crew must pour concrete near a 13.8 kV overhead line. The required minimum crane clearance is 10 feet; the correct control is to have the utility de-energize and ground the line, or maintain 10 feet with a dedicated spotter. Issuing rubber gloves or hard hats does not control the hazard - protecting the worker is not the same as controlling the hazard.