Chapter 2 of 524% of exam
Construction Hazards and the Focus Four
Construction is among the most dangerous industries, and most deaths trace back to four hazard categories known as the Focus Four: falls, struck-by, caught-in/between, and electrocution. This chapter explains how to recognize these hazards, along with excavation and confined-space dangers, and how the hierarchy of controls guides the safest response. Recognizing hazards early and controlling them at the source saves lives.
The Focus Four
The Focus Four hazards account for the large majority of construction fatalities every year. Falls are the single largest cause of death, followed by struck-by, caught-in/between, and electrocution. Because these four are so deadly, training and enforcement place heavy emphasis on each of them.
Falls lead all causes
Falls from roofs, ladders, scaffolds, and openings cause roughly a third of construction deaths.
Struck-by hazards
Workers can be struck by flying, falling, swinging, or rolling objects such as loads, tools, or vehicles.
Caught-in/between hazards
These include cave-ins, being pulled into machinery, and being crushed between equipment and a fixed object.
Electrocution hazards
Contact with power lines, faulty wiring, and energized equipment causes many fatal shocks.
Hierarchy of Controls
When a hazard is identified, the hierarchy of controls guides the most effective response. The order, from most to least effective, is elimination, substitution, engineering controls, administrative controls, and personal protective equipment. Higher-level controls are preferred because they do not depend on individual worker behavior.
Elimination is best
Removing the hazard entirely is the most effective control because the danger no longer exists.
Engineering controls
Physical measures such as guards, ventilation, and trench shields isolate workers from the hazard.
PPE is last
Personal protective equipment is the least effective control and a last line of defense, not a substitute for other controls.
Struck-By and Caught-In/Between
Struck-by injuries occur when a worker is hit by a moving object, while caught-in/between injuries involve being squeezed, pinned, or crushed. Vehicles, suspended loads, unguarded machinery, and collapsing structures are common sources. Controls focus on separating workers from moving objects and energy.
Barricade swing radius
Keep workers out of the swing radius of cranes and excavators to prevent struck-by and crushing injuries from the rotating counterweight.
Never stand under loads
Workers must stay clear of suspended loads and inspect rigging before every lift.
Guard machinery
Machine guarding and lockout/tagout prevent body parts from being caught in moving parts.
High-visibility and spotters
High-visibility clothing, trained spotters, and backup alarms reduce vehicle struck-by incidents.
Excavation and Trenching
Trench cave-ins are a deadly caught-in/between hazard because soil is extremely heavy and can bury a worker in seconds. A competent person must evaluate and inspect excavations, and protective systems are required as depth increases. Water, vibration, and previously disturbed soil all raise the risk of collapse.
Protective systems at 5 feet
Excavations 5 feet or deeper generally require sloping, benching, shoring, or shielding unless made of stable rock.
Keep spoil 2 feet back
Excavated soil and materials must be kept at least 2 feet from the trench edge.
Egress within 25 feet
In trenches 4 feet or deeper, a ladder, ramp, or stairway must be within 25 feet of workers.
Competent person inspection
A competent person must inspect excavations daily and after any event that increases the hazard.
Confined Spaces and Hazard Recognition
Confined spaces such as tanks, vaults, and manholes can contain deadly atmospheres or engulfment hazards. Permit-required confined spaces demand atmospheric testing, permits, and an attendant. Recognizing hazards through tools like a Job Hazard Analysis is the first step toward controlling them.
Test the atmosphere first
Before entry, test for oxygen, then flammable gases, then toxic contaminants, and continue monitoring.
Use a permit and attendant
Permit-required confined spaces require a written permit and an attendant stationed outside the space.
Job Hazard Analysis
A JHA breaks a task into steps and identifies the hazards and controls for each before work begins.
Report hazards promptly
Workers should report any hazard they cannot correct to a supervisor or competent person immediately.
Test your knowledge
Practice questions on Construction Hazards and the Focus Four