OSHA 30 Construction — All Questions
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94 questions
What are the 'Focus Four' hazards responsible for most construction deaths?
- a.Noise, dust, heat, and cold
- b.Falls, struck-by, caught-in/between, and electrocution✓
- c.Slips, trips, cuts, and bruises
- d.Fire, flood, wind, and earthquake
OSHA's Focus Four are falls, struck-by, caught-in/between, and electrocution hazards. These four categories account for the majority of construction fatalities each year. Training emphasizes recognizing and controlling each of them.
Which of the Focus Four hazards causes the greatest number of construction fatalities?
- a.Falls✓
- b.Struck-by
- c.Caught-in/between
- d.Electrocution
Falls are consistently the leading cause of death in construction, making up roughly a third of all industry fatalities. This is why fall protection receives heavy regulatory emphasis. Preventing falls has the greatest single impact on construction safety.
A worker is hit by a swinging load from a crane. Which Focus Four category does this fall under?
- a.Struck-by✓
- b.Caught-in/between
- c.Electrocution
- d.Fall
Being hit by a moving or swinging object such as a crane load is a struck-by hazard. Struck-by incidents also include flying, falling, and rolling objects. Controls include barricading swing zones and keeping workers clear of suspended loads.
A worker's arm is pulled into an unguarded rotating drive shaft. This is an example of which hazard?
- a.Chemical exposure
- b.Caught-in/between✓
- c.Struck-by
- d.Fall
Having a body part drawn into or crushed by machinery is a caught-in/between hazard. Machine guarding and lockout/tagout are key controls for these hazards. Rotating equipment must be guarded to prevent contact with moving parts.
What is the primary purpose of a competent person on a construction site?
- a.To identify hazards and have authority to correct them promptly✓
- b.To manage payroll
- c.To greet visitors
- d.To order lunch for the crew
A competent person is someone capable of identifying existing and predictable hazards and who has the authorization to take prompt corrective measures. OSHA requires a competent person for many activities, such as scaffolding, excavation, and fall protection. Their authority to act is a defining feature of the role.
Which control is considered MOST effective in the hierarchy of controls?
- a.Administrative controls
- b.Personal protective equipment
- c.Warning signs
- d.Elimination of the hazard✓
In the hierarchy of controls, elimination of the hazard is the most effective method because it removes the danger entirely. The full order is elimination, substitution, engineering controls, administrative controls, and PPE. PPE is the least effective and a last line of defense.
Before entering an excavation deeper than 5 feet, what is generally required?
- a.Permission from customers
- b.Nothing, if the soil looks stable
- c.A protective system such as sloping, shoring, or shielding✓
- d.Only a hard hat
Excavations 5 feet or deeper generally require a protective system such as sloping, benching, shoring, or a trench shield, unless made entirely of stable rock. A competent person must inspect the excavation. Trench cave-ins are a deadly caught-in/between hazard.
Where should excavated soil (spoil pile) be placed relative to the edge of a trench?
- a.Inside the trench
- b.Directly on the trench edge
- c.It does not matter
- d.At least 2 feet back from the edge✓
Spoil piles and other materials must be kept at least 2 feet back from the edge of an excavation. This reduces the load on the trench walls and prevents materials from rolling back in. Keeping the edge clear also gives workers a safe exit path.
What is the maximum distance a worker in a trench 4 feet or deeper should be from a means of egress?
- a.There is no requirement
- b.100 feet
- c.50 feet
- d.25 feet✓
In trenches 4 feet or deeper, a stairway, ladder, ramp, or other safe means of egress must be within 25 feet of workers. This ensures a quick exit in an emergency such as a cave-in or water intrusion. The means of egress must extend above the trench top edge.
Which practice best reduces struck-by hazards from vehicles and equipment on site?
- a.Using high-visibility clothing, spotters, and traffic control✓
- b.Removing backup alarms
- c.Wearing dark clothing
- d.Standing behind backing vehicles
Struck-by hazards from vehicles are reduced by high-visibility clothing, trained spotters, backup alarms, and traffic control plans. Workers should stay out of the blind spots of heavy equipment. Establishing exclusion zones keeps workers separated from moving equipment.
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A tool left on an overhead beam falls and strikes a worker below. What is the best preventive measure?
- a.Toe boards, tool tethers, and barricading areas below overhead work✓
- b.Ignoring the area below
- c.Working faster
- d.Removing all hard hats
Falling-object struck-by hazards are controlled with toe boards, screens, tool tethers, and barricading the area below overhead work. Hard hats provide protection but should not be the only control. Keeping tools secured at height prevents them from becoming projectiles.
Which hard hat class provides electrical protection up to 20,000 volts?
- a.Class G
- b.Class C
- c.Class E✓
- d.There is no such rating
Class E (Electrical) hard hats are tested to provide protection against contact with up to 20,000 volts. Class G (General) is rated to 2,200 volts, and Class C (Conductive) offers no electrical protection. Selecting the right class matters near energized equipment.
Which is a common caught-in/between hazard during trenching operations?
- a.Sunburn
- b.Loud noise
- c.Slippery floors
- d.Cave-in of unprotected trench walls✓
A cave-in of unprotected trench walls is a deadly caught-in/between hazard because soil is extremely heavy and can bury a worker in seconds. Protective systems and competent-person inspections are essential. Even shallow collapses can cause fatal crushing injuries.
What is the purpose of a Job Hazard Analysis (JHA)?
- a.To break a job into steps and identify hazards and controls for each✓
- b.To advertise the company
- c.To schedule vacations
- d.To calculate wages
A Job Hazard Analysis breaks a task into individual steps, identifies the hazards associated with each step, and determines controls to reduce risk. It is a proactive tool for planning safe work. Involving workers who perform the task improves its accuracy.
When working near unstable overhead materials or structures, what is the best first action?
- a.Barricade the area and keep workers out until it is made safe✓
- b.Increase the load
- c.Remove warning signs
- d.Work directly beneath it quickly
Areas with unstable overhead materials should be barricaded and kept clear until the hazard is stabilized or removed. Only trained personnel with proper controls should address the instability. Keeping workers out of the danger zone prevents struck-by and crushing injuries.
Which factor most increases the danger of a trench collapse?
- a.A shallow depth of 1 foot
- b.Dry, cool weather
- c.Bright sunlight
- d.Previously disturbed soil, water intrusion, and vibration from equipment✓
Previously disturbed soil, water accumulation, and vibration from nearby traffic or equipment all increase the likelihood of a trench collapse. A competent person must evaluate these conditions. Soil that has been dug before does not hold together as reliably as undisturbed ground.
What does 'housekeeping' on a construction site help prevent?
- a.Higher wages
- b.Slips, trips, falls, fires, and struck-by hazards from clutter✓
- c.Faster internet
- d.Only aesthetic problems
Good housekeeping keeps walkways clear and removes debris, reducing slips, trips, falls, fire fuel, and struck-by hazards. Materials should be stored neatly and scrap removed regularly. A clean site is a strong indicator of an overall safe operation.
A rigging chain snaps and the load drops. Which Focus Four hazard is most directly involved?
- a.Caught-in/between
- b.Chemical
- c.Struck-by✓
- d.Electrocution
A dropped load from failed rigging is a struck-by falling-object hazard. Rigging must be inspected before use and rated for the load. Workers should never stand under a suspended load.
What is a permit-required confined space?
- a.Any small office
- b.A parking lot
- c.A break room
- d.A confined space with hazards such as toxic atmosphere, engulfment, or entrapment requiring a permit✓
A permit-required confined space has one or more serious hazards, such as a hazardous atmosphere, potential for engulfment, or a configuration that could trap or asphyxiate an entrant. Entry requires atmospheric testing, a permit, and an attendant. These procedures prevent deaths in tanks, vaults, and manholes.
Before entering a permit-required confined space, what must be done regarding the atmosphere?
- a.Spray air freshener
- b.Test the atmosphere for oxygen, flammability, and toxicity✓
- c.Light a match to check for gas
- d.Nothing, just enter quickly
The atmosphere of a permit-required confined space must be tested before entry for oxygen content, flammable gases, and toxic contaminants, in that order. Testing continues or is monitored during entry. Never rely on smell or appearance to judge atmospheric safety.
Which of the following is an engineering control for a construction hazard?
- a.A safety poster
- b.A written policy
- c.A warning email
- d.A machine guard that physically blocks contact with moving parts✓
An engineering control physically removes or isolates a hazard, such as a machine guard, ventilation system, or trench shield. Engineering controls rank above administrative controls and PPE in the hierarchy. They protect workers without depending on individual behavior.
What is the main reason to keep workers out of the 'swing radius' of a crane or excavator?
- a.To prevent struck-by and caught-in/between injuries from the rotating counterweight✓
- b.To reduce noise
- c.To improve the view
- d.To save fuel
The rotating superstructure and counterweight of a crane or excavator can strike or crush a worker caught between it and a fixed object. The swing radius should be barricaded to keep workers out. This is a well-documented cause of construction fatalities.
Which is the correct order of the hierarchy of controls from most to least effective?
- a.Elimination, substitution, engineering controls, administrative controls, PPE✓
- b.Substitution, PPE, elimination, engineering, administrative
- c.PPE, administrative, engineering, substitution, elimination
- d.Administrative, PPE, elimination, engineering, substitution
The correct hierarchy from most to least effective is elimination, substitution, engineering controls, administrative controls, and PPE. Higher-level controls are more reliable because they do not depend on worker behavior. PPE is the last line of defense.
What should a worker do if they discover a hazard they cannot correct themselves?
- a.Report it to a supervisor or competent person immediately✓
- b.Cover it up
- c.Ignore it
- d.Wait until the next inspection
A worker who finds a hazard beyond their ability to fix should report it to a supervisor or competent person right away. Prompt reporting allows corrective action before someone is hurt. Marking or barricading the hazard temporarily can protect others in the meantime.
Struck-by hazards are commonly divided into four categories. Which set correctly lists them?
- a.Chemical, biological, radioactive, and electrical
- b.Flying, falling, swinging, and rolling objects✓
- c.Hot, cold, wet, and dry surfaces
- d.Loud, bright, sharp, and heavy items
OSHA's Focus Four training groups struck-by hazards into flying, falling, swinging, and rolling objects. Examples include nail-gun projectiles, dropped tools, crane loads, and vehicles. Recognizing the type guides the right control under the 29 CFR 1926 standards.OSHA Focus Four (struck-by)
What is the key difference between a 'struck-by' and a 'caught-in/between' injury?
- a.Struck-by comes from impact alone; caught-in/between involves being crushed or compressed✓
- b.Struck-by injuries only ever happen indoors
- c.There is no real difference between the two for typical light-duty operations for most residential-scale jobs
- d.Caught-in injuries only involve electricity
In a struck-by injury the impact of an object causes the harm, while in a caught-in/between injury the worker is crushed, caught, or compressed between objects. A swinging load is struck-by; a worker pinned between equipment and a wall is caught-between. OSHA uses this distinction in Focus Four training.OSHA Focus Four
Which tool is a common source of struck-by injuries from flying fasteners?
- a.A powder-actuated or pneumatic nail gun✓
- b.A hand-held tape measure
- c.A chalk line reel
- d.A carpenter's marking pencil when working away from the edge
Powder-actuated tools and pneumatic nailers can drive or ricochet fasteners at high speed, a serious flying-object struck-by hazard. Under 29 CFR 1926.302, only trained operators may use powder-actuated tools. Eye and face protection is required.29 CFR 1926.302
To protect against flying particles when grinding or cutting, a worker must primarily use what?
- a.A standard baseball cap
- b.Eye and face protection meeting ANSI Z87.1✓
- c.A cloth face covering
- d.A pair of ordinary reading glasses provided the weather stays clear
Flying particles from grinding, cutting, and chipping are a struck-by hazard controlled by ANSI Z87.1 eye and face protection under 29 CFR 1926.102. Face shields are worn over primary eye protection for heavy operations. Ordinary glasses do not qualify.29 CFR 1926.102
Freshly built concrete masonry walls under construction must be braced to prevent which hazard?
- a.Collapse that could strike workers (a struck-by hazard)✓
- b.Excessive water evaporation during the earlier phases of work
- c.Gradual color fading
- d.Slower curing of the mortar
Under 29 CFR 1926.706, a limited access zone must be established and masonry walls over 8 feet must be adequately braced until permanent supports are in place. This prevents a wall collapse from striking workers. Unbraced walls have caused fatal struck-by incidents.29 CFR 1926.706
During concrete and masonry construction, where must workers not be permitted relative to raised loads?
- a.Directly under a concrete bucket being elevated or lowered✓
- b.Only inside a fully enclosed building
- c.Within one mile of the crane at all
- d.Anywhere on the site during any lifting as long as the tools look intact
Under 29 CFR 1926.701, no worker may be permitted under concrete buckets while they are being elevated or lowered. Buckets are routed to minimize worker exposure. This reduces struck-by risk from falling concrete or a dropped bucket.29 CFR 1926.701
Which is a primary caught-in/between hazard on construction sites?
- a.Glare from bright direct sunlight
- b.A sunburn on a hot afternoon
- c.An unprotected trench cave-in✓
- d.A minor paper cut on the hand
Trench and excavation cave-ins are a leading caught-in/between hazard because soil is extremely heavy. Under 29 CFR 1926.652, protective systems are required at 5 feet or deeper. A cubic yard of soil can weigh as much as a car.29 CFR 1926.652
Machine guarding is primarily intended to protect against which hazard?
- a.Cold outdoor weather
- b.Overexposure to sunlight when only one worker is involved
- c.Loud radio music nearby
- d.Caught-in/between injuries from moving parts✓
Machine guards prevent body parts and clothing from being caught in belts, gears, and rotating shafts, a caught-in/between hazard. Under 29 CFR 1926.300, moving parts must be guarded. Guarding is an engineering control high in the hierarchy.29 CFR 1926.300
A worker positioned between a backing dump truck and a concrete wall faces which hazard?
- a.An occupational noise hazard under most routine jobsite conditions
- b.A heat-illness hazard
- c.A silica inhalation hazard
- d.A caught-in/between (crushing) hazard✓
Being pinned between mobile equipment and a fixed object is a caught-between crushing hazard that can be fatal. Spotters, backup alarms, and exclusion zones under 29 CFR 1926.601 reduce the risk. Workers should never stand in the path of backing equipment.29 CFR 1926.601
Under OSHA's crane standard, who must handle rigging when workers are within the fall zone during assembly/disassembly?
- a.The site's front-desk receptionist
- b.A qualified rigger✓
- c.An untrained first-day apprentice
- d.Any available general laborer
Under 29 CFR 1926.1404 and 1926.1425, a qualified rigger must handle rigging during assembly/disassembly and when workers are within the fall zone. A qualified rigger has the training and experience to select and inspect rigging. This reduces struck-by risk from dropped loads.29 CFR 1926.1425
Under the OSHA crane standard, operators of most cranes must be:
- a.Related to the site owner by family when the crew is short on time
- b.At least sixty years of age
- c.Certified or qualified to operate the equipment✓
- d.Fluent in at least three languages
Under 29 CFR 1926.1427, most crane operators must be certified or qualified. Certification is by type and, where applicable, capacity. Proper qualification reduces the risk of overloads and tip-overs.29 CFR 1926.1427
For power lines up to 350 kV, what minimum clearance does OSHA's crane standard set in the assembly/disassembly zone (Table A)?
- a.5 feet
- b.20 feet✓
- c.2 feet
- d.6 inches
Under 29 CFR 1926.1408 Table A, cranes must keep at least 20 feet from power lines up to 350 kV unless the line is de-energized and grounded or other options are used. Higher voltages require greater clearance. Power-line contact is a top cause of crane electrocutions.29 CFR 1926.1408
How often must a competent person inspect a crane that is in service?
- a.Only when it is first purchased
- b.Each shift the crane is used✓
- c.Never, unless it visibly breaks
- d.Once every five calendar years
Under 29 CFR 1926.1412, a competent person must conduct a shift inspection of each crane before or during each shift of use. Monthly and annual comprehensive inspections are also required. Inspections catch defects before failure.29 CFR 1926.1412
What is the purpose of a tag line on a crane load?
- a.To measure the load's temperature
- b.To let a worker control the load's movement from a safe distance✓
- c.To increase the crane's lifting capacity for the majority of standard tasks
- d.To power the crane's engine
Under 29 CFR 1926.1417, a tag line is a rope used to guide and steady a suspended load from a safe distance, reducing swinging and struck-by risk. Workers should stay out from under the load. Tag lines are a basic rigging control.29 CFR 1926.1417
Before each use, wire-rope slings and rigging hardware must be:
- a.Weighed carefully on a scale
- b.Painted a bright warning color based on the project's own schedule
- c.Inspected and removed from service if damaged✓
- d.Soaked overnight in water
Under 29 CFR 1926.251, slings and rigging must be inspected each shift and damaged slings removed from service. Broken wires, kinks, and corrosion are rejection criteria. Failed rigging drops loads, a serious struck-by hazard.29 CFR 1926.251
Exceeding a crane's rated capacity most directly risks which outcome?
- a.A significantly longer equipment lifespan in the absence of a written program
- b.Faster load cycles with no added risk
- c.Noticeably improved fuel economy
- d.Tip-over or structural failure of the crane✓
Operating beyond the rated capacity shown on the load chart can cause the crane to tip over or fail structurally. Under 29 CFR 1926.1417, operators must not exceed manufacturer limits. Load charts account for boom length and radius.29 CFR 1926.1417
When must a motor-vehicle or equipment operator on a construction site wear a seat belt?
- a.Only when traveling above 40 mph
- b.Whenever operating equipment that is equipped with seat belts✓
- c.Only when a supervisor is present
- d.Only when driving on a public highway as a general rule of thumb on site
Under 29 CFR 1926.601, seat belts must be provided and used in motor vehicles that have them. Seat belts and rollover protection guard operators during rollovers. Rollover fatalities are common with earthmoving equipment.29 CFR 1926.601
What does ROPS stand for on earthmoving equipment?
- a.Rollover Protective Structure✓
- b.Reinforced Oil Pressure Seal
- c.Remote Operating Power System
- d.Rapid Off-road Positioning Sensor
ROPS means Rollover Protective Structure, required on much earthmoving equipment under 29 CFR 1926.1001 and Subpart W. Combined with a seat belt, it protects the operator if the machine overturns. ROPS must meet specified performance criteria.29 CFR 1926 Subpart W
When may earthmoving equipment operate in reverse near workers without an audible backup alarm?
- a.Whenever the jobsite radio is loud
- b.Any time the operator is in a hurry once the initial setup is complete
- c.Only during the nighttime hours
- d.Only when a signal person (spotter) directs the movement✓
Under 29 CFR 1926.601, bidirectional machines and vehicles with obstructed rear views must have a reverse-signal alarm audible above ambient noise, or a spotter must signal when it is safe to back up. Backing incidents cause many struck-by fatalities. Spotters must stay out of the blind spot.29 CFR 1926.601
Before using a vehicle at the start of a shift, an operator should:
- a.Cover the mirrors to reduce glare
- b.Remove the seat belt for more comfort
- c.Check the brakes, lights, horn, and other safety devices✓
- d.Disable the reverse-signal backup alarm for typical light-duty operations
Under 29 CFR 1926.601, vehicles must be checked at the beginning of each shift to ensure brakes, lights, warning devices, and other parts are in safe condition. Defective vehicles are taken out of service. Pre-use checks prevent equipment incidents.29 CFR 1926.601
How should stored materials be arranged to prevent tipping and struck-by hazards?
- a.Left loose on a sloped surface
- b.Stacked, blocked, or interlocked and limited in height to stay stable✓
- c.Balanced carefully on a single point
- d.Piled as high as possible with no limit when working away from the edge
Under 29 CFR 1926.250, materials must be stacked, racked, blocked, interlocked, or otherwise secured and kept at stable heights. Aisles and passageways must be kept clear. Unstable stacks collapse and strike workers.29 CFR 1926.250
When a loose brick stack rises higher than 4 feet, OSHA requires that it be:
- a.Stored only during rainy weather
- b.Tapered back 2 inches for every foot above the 4-foot level✓
- c.Stacked straight up to 20 feet with no taper
- d.Leaned against the nearest worker for support provided the weather stays clear
Under 29 CFR 1926.250(a), brick stacks over 4 feet must be tapered back 2 inches for every foot of height above the 4-foot level and limited to 7 feet high. Tapering prevents toppling. This is a classic materials-handling rule.29 CFR 1926.250(a)
Material stored inside a building under construction must not be placed within how many feet of a hoistway or floor opening?
- a.6 feet✓
- b.50 feet
- c.2 feet
- d.1 inch
Under 29 CFR 1926.250(b), material stored inside buildings must not be placed within 6 feet of any hoistway or inside floor opening, nor within 10 feet of an exterior wall that does not extend above the material. This keeps materials from falling into openings. Clear zones protect workers below.29 CFR 1926.250(b)
When debris is dropped through floor holes without an enclosed chute, OSHA requires the drop area to be:
- a.Left completely open for easy access
- b.Ignored entirely if the hole is small
- c.Marked with a single cone a week later as long as the tools look intact
- d.Enclosed with barricades and posted with warning signs✓
Under 29 CFR 1926.252, when material is dropped through holes without an enclosed chute, the drop area must be barricaded not less than 42 inches high and kept 6 feet back from the edge, with warning signs posted. An enclosed chute is required for drops over 20 feet. This protects workers below.29 CFR 1926.252
How often must a competent person inspect an excavation where workers are present?
- a.Daily and as conditions change, before workers enter✓
- b.Only after an actual collapse for most residential-scale jobs
- c.Once per calendar month
- d.Never once it has been dug
Under 29 CFR 1926.651(k), a competent person must inspect excavations daily, before each shift, after rainstorms, and as conditions change. If hazards are found, workers are removed until it is safe. Daily inspection is central to trench safety.29 CFR 1926.651(k)
In OSHA's soil classification system, which soil type is the LEAST stable?
- a.Stable rock
- b.Type A
- c.Type C✓
- d.Type B
Under 29 CFR 1926 Subpart P Appendix A, Type C soil is the least stable, including granular soils and submerged soil. Type A is most stable and stable rock is solid natural mineral matter. Soil type determines allowable slopes.29 CFR 1926 Subpart P App A