OSHA 30 Construction — All 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.

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

For a simple sloped excavation in Type C soil, what is the maximum allowable slope?

• a.Vertical walls at 90 degrees
• b.One-quarter horizontal to 1 vertical under most routine jobsite conditions
• c.1.5 horizontal to 1 vertical (about 34 degrees)✓
• d.Straight walls with no slope at all

Under 29 CFR 1926 Subpart P Appendix B, Type C soil must be sloped no steeper than 1.5 to 1, roughly a 34-degree angle from horizontal. Less stable soil needs flatter slopes. Sloping is one protective-system option.29 CFR 1926 Subpart P App B

Before digging begins, underground utility installations should be:

• a.Located and marked, then supported or protected during the work✓
• b.Assumed simply not to exist there as some contractors interpret the rule
• c.Left entirely to random chance
• d.Cut through without any checking

Under 29 CFR 1926.651(b), the estimated location of utility installations must be determined before excavation, often by calling the one-call (811) service. Utilities are supported or protected during work. Striking a gas or electric line can be deadly.29 CFR 1926.651(b)

A trench box (shield) used in an excavation must:

• a.Be made from ordinary cardboard
• b.Cover only half of the workers
• c.Be rated for the depth and soil and protect workers inside✓
• d.Sit 5 feet above the trench bottom when the crew is short on time

Under 29 CFR 1926.652, trench shields must be designed for the loads of the excavation and installed so workers are protected, with workers staying within the protected zone. Manufacturer tabulated data governs its use. Shields are one accepted protective system.29 CFR 1926.652

When water accumulates in an excavation, workers may only continue if:

• a.The trench simply appears to be fine according to older industry practice
• b.They work faster to finish sooner
• c.They ignore the standing water
• d.Special support, water removal, or harnesses and controls are used✓

Under 29 CFR 1926.651(h), workers must not work in excavations with accumulated water unless precautions such as special support, water removal, or harnesses and lifelines are taken. Water undermines trench walls and raises collapse risk. A competent person monitors the conditions.29 CFR 1926.651(h)

Protective systems for excavations deeper than 20 feet must be designed by:

• a.A registered professional engineer✓
• b.Any general worker on the site
• c.The nearest available truck driver
• d.The equipment rental counter clerk

Under 29 CFR 1926.652, protective systems for excavations over 20 feet deep must be designed by a registered professional engineer. Shallower systems may use tabulated data or the appendices. Deep excavations carry the highest cave-in risk.29 CFR 1926.652

When mobile equipment operates near an excavation and the operator cannot see the edge, what is required?

• a.Barricades, hand or mechanical signals, or stop logs✓
• b.Nothing at all is required
• c.A note left back in the office
• d.A single cone placed a mile away for the majority of standard tasks

Under 29 CFR 1926.651(f), when equipment operates near the edge and the operator cannot see it, a warning system such as barricades, hand or mechanical signals, or stop logs must be used. This prevents equipment from rolling into the trench. It also protects workers inside.29 CFR 1926.651(f)

A scaffold and its components must support their own weight plus at least how many times the maximum intended load?

• a.Exactly 1 time the load
• b.Only one-half of the load based on the project's own schedule
• c.4 times the maximum intended load✓
• d.A full 10 times the load

Under 29 CFR 1926.451(a), scaffolds must support their own weight and at least 4 times the maximum intended load. Suspension ropes and hardware use a 6-to-1 safety factor. These margins prevent overloading failures.29 CFR 1926.451(a)

Beyond a 4-to-1 height-to-base ratio, a supported scaffold must be:

• a.Weighted only with loose bricks
• b.Painted for added stability
• c.Restrained from tipping by guying, tying, or bracing✓
• d.Left free-standing at any height in the absence of a written program

Under 29 CFR 1926.451(c), supported scaffolds more than 4 times as tall as their minimum base width must be restrained from tipping by guys, ties, or braces at required intervals. This prevents overturning. Tall scaffolds are especially vulnerable to wind and load shifts.29 CFR 1926.451(c)

How must workers gain access to a scaffold platform?

• a.By jumping from an adjacent roof
• b.By a ladder, stair tower, ramp, or other designed access✓
• c.By being lifted by hand in a bucket
• d.By climbing the diagonal cross braces as a general rule of thumb on site

Under 29 CFR 1926.451(e), safe access such as a ladder, stairway, or ramp must be provided when the platform is more than 2 feet above or below a point of access. Cross braces are not acceptable access. Climbing braces causes falls.29 CFR 1926.451(e)

Suspension scaffold ropes must have a safety factor of at least:

• a.2 to 1
• b.1 to 1
• c.6 to 1✓
• d.1 to 2

Under 29 CFR 1926.451(a), suspension ropes and connecting hardware must support at least 6 times the maximum intended load. This higher factor reflects the consequences of a suspension failure. Ropes are inspected before each use.29 CFR 1926.451(a)

Who must supervise the erection, moving, and dismantling of scaffolds?

• a.No particular person at all
• b.A competent person✓
• c.A visiting client or guest
• d.The newest apprentice on site

Under 29 CFR 1926.451(f), scaffold erection, moving, dismantling, and alteration must be done under the supervision of a competent person and by trained, experienced workers. This reduces collapse and fall risk during the most dangerous phases. A qualified person designs the scaffold.29 CFR 1926.451(f)

Who must train each employee who works on a scaffold to recognize its hazards?

• a.Any coworker with a smartphone
• b.No one; training is not needed
• c.The manufacturer's website alone
• d.A qualified person✓

Under 29 CFR 1926.454, a qualified person must train each employee who works on a scaffold to recognize the hazards and understand the procedures to control them. Retraining is required when conditions or the scaffold type change. Training reduces scaffold falls and collapses.29 CFR 1926.454

When a break in elevation of 19 inches or more exists and no ramp or runway is provided, OSHA requires:

• a.Only a posted warning sign
• b.A stairway or a ladder✓
• c.Nothing at all is required
• d.A rope to slide down on

Under 29 CFR 1926.1051, a stairway or ladder must be provided at all points of access where there is a break in elevation of 19 inches or more and no ramp, runway, or hoist is in place. This prevents falls and awkward climbs. It is a core Subpart X requirement.29 CFR 1926.1051

A stairway with four or more risers, or rising more than 30 inches, must have:

• a.A loose rope draped across it
• b.No railing of any kind at all
• c.At least one handrail and stair rail✓
• d.A ladder bolted across the steps provided the weather stays clear

Under 29 CFR 1926.1052, stairways with 4 or more risers or rising more than 30 inches must have at least one handrail and a stair rail along each unprotected side or edge. Handrails help prevent falls on stairs. Temporary stairs need the same protection.29 CFR 1926.1052

Portable ladder rungs must be spaced how far apart and be uniform?

• a.Spacing does not matter at all
• b.Between 24 and 30 inches apart
• c.Between 2 and 4 inches apart
• d.Between 10 and 14 inches apart✓

Under 29 CFR 1926.1053, ladder rungs must be spaced between 10 and 14 inches apart and be parallel, level, and uniform. Uniform spacing prevents missteps. Rungs must also be slip-resistant.29 CFR 1926.1053

How must a worker face while climbing a ladder?

• a.Toward the ladder, using three points of contact✓
• b.Away from the ladder to watch below as long as the tools look intact
• c.Backward to keep an eye on traffic
• d.Sideways while carrying heavy tools

Under 29 CFR 1926.1053(b), workers must face the ladder when climbing and maintain three points of contact. Tools should be hoisted or carried in a belt, not in the hands. This reduces the risk of falls.29 CFR 1926.1053(b)

Portable ladders must generally be capable of supporting at least how many times the maximum intended load?

• a.Exactly the load with no margin for most residential-scale jobs
• b.A full 20 times the load
• c.One-quarter of the load
• d.4 times the maximum intended load✓

Under 29 CFR 1926.1053, ladders must support at least 4 times the maximum intended load, with extra-heavy-duty type 1A ladders held to higher requirements. Overloading a ladder can cause sudden failure. Users must observe the duty rating.29 CFR 1926.1053

Why should ladders with conductive (metal) side rails be avoided near electrical work?

• a.Metal can conduct electricity and cause electrocution✓
• b.Metal ladders are simply too heavy
• c.Metal ladders rust almost instantly
• d.Metal ladders are illegal everywhere when only one worker is involved

Under 29 CFR 1926.1053(b), portable ladders with conductive siderails may not be used near energized electrical equipment where the worker or ladder could contact the electricity. Non-conductive fiberglass ladders are used for electrical work. Metal ladders create an electrocution path.29 CFR 1926.1053(b)

Electrocution is one of the Focus Four. Which situation is a leading construction electrocution hazard?

• a.Standing near an ordinary light switch under most routine jobsite conditions
• b.Using a battery-powered flashlight
• c.Reading a monthly electricity bill
• d.Contact with overhead or buried power lines✓

Contact with overhead and buried power lines is a leading electrocution hazard in construction, especially with cranes, ladders, and scaffolds. Under 29 CFR 1926.416, workers must maintain safe clearances and assume lines are live. Electrocution is one of the deadly Focus Four.29 CFR 1926.416

Which practice reduces struck-by injuries in a highway work zone?

• a.Letting workers stand in live traffic lanes as some contractors interpret the rule
• b.Removing all signs to speed up traffic
• c.A temporary traffic control plan with signs, devices, and flaggers✓
• d.Turning off all of the warning lights

Under 29 CFR 1926 Subpart G and the MUTCD, work zones require a traffic control plan with advance warning signs, channelizing devices, and trained flaggers. High-visibility apparel is also required. These controls separate workers from moving traffic.29 CFR 1926.201

High-visibility warning garments for flaggers protect against which hazard?

• a.Loud noise
• b.Chemical burns
• c.Falls from height when the crew is short on time
• d.Being struck by moving vehicles✓

Under 29 CFR 1926.201, flaggers must wear high-visibility garments so drivers can see them, reducing struck-by risk from vehicles. Warning garments are required day and night, with retroreflective material at night. Visibility is the flagger's main protection.29 CFR 1926.201

Reinforcing steel (rebar) onto which workers could fall must be:

• a.Guarded with covers to prevent impalement✓
• b.Sharpened to make work easier
• c.Left exposed and sharp for the crew according to older industry practice
• d.Painted but still left uncapped

Under 29 CFR 1926.701(b), all protruding reinforcing steel onto or into which workers could fall must be guarded to eliminate the hazard of impalement. Rebar caps or troughs are commonly used. Impalement is a severe struck-by and fall consequence.29 CFR 1926.701(b)

What is the main purpose of a barricade around a hazardous area?

• a.To store extra hand tools
• b.To provide seating for breaks
• c.To keep unauthorized workers out of the danger zone✓
• d.To decorate the construction site unless a supervisor decides otherwise

Barricades physically separate workers from hazards such as swing radii, drop zones, and open excavations. Under 29 CFR 1926.202, they are used with signs and tags. Keeping people out of the danger zone prevents struck-by and caught-in injuries.29 CFR 1926.202

Danger signs on a construction site indicate:

• a.A good place to take a lunch break for the majority of standard tasks
• b.The company's daily business hours
• c.Immediate hazards where special precautions are necessary✓
• d.The directions to the parking lot

Under 29 CFR 1926.200, danger signs are used only where an immediate hazard exists and special precautions are needed; they use red, black, and white. Caution signs warn of potential hazards. Standardized signage speeds hazard recognition.29 CFR 1926.200

A 'Do Not Use' or 'Out of Service' tag on equipment serves what purpose?

• a.To show the battery is fully charged based on the project's own schedule
• b.To warn workers not to operate the unsafe equipment✓
• c.To show the equipment is brand new
• d.To advertise the equipment for sale

Accident-prevention tags under 29 CFR 1926.200(h) warn of hazards such as defective tools or equipment out of service. They stay in place until the hazard is eliminated. Tags supplement, but do not replace, guarding or lockout.29 CFR 1926.200(h)

Fire extinguishers rated for which class are used on ordinary combustibles like wood and paper?

• a.Class A✓
• b.Class B for flammable liquids
• c.Class D for combustible metals
• d.Class C for energized electrical

Class A extinguishers are for ordinary combustibles such as wood, paper, and cloth. Class B is for flammable liquids, Class C for energized electrical, and Class D for combustible metals. Under 29 CFR 1926.150, appropriate firefighting equipment must be provided.29 CFR 1926.150

On a construction site, how far, at most, should a worker travel to reach a fire extinguisher for ordinary combustibles?

• a.Up to a half mile away
• b.The distance does not matter
• c.No more than 100 feet✓
• d.No more than 5 feet

Under 29 CFR 1926.150, a fire extinguisher rated at least 2A must be provided so the travel distance to the nearest unit does not exceed 100 feet. Extinguishers must be accessible and maintained. Quick access limits fire spread.29 CFR 1926.150

Flammable liquids in a construction area must be stored in:

• a.Approved closed containers and safety cans✓
• b.Ordinary paper grocery bags
• c.Open buckets set near heaters
• d.Uncovered glass jars in sunlight where the foreman signs off on it

Under 29 CFR 1926.152, flammable liquids must be kept in approved closed containers or safety cans and stored away from ignition sources. Quantities in work areas are limited. Proper storage prevents fires and vapor buildup.29 CFR 1926.152

Compressed gas cylinders in storage must be:

• a.Stacked freely without any restraint
• b.Laid loose on their sides near sparks once the initial setup is complete
• c.Secured upright with valve caps on and away from heat✓
• d.Stored right next to open flames

Under 29 CFR 1926.350, compressed gas cylinders must be secured to prevent tipping, kept with valve protection caps in place when not in use, and separated from ignition sources. Oxygen and fuel-gas cylinders are stored apart. A falling cylinder can rupture violently.29 CFR 1926.350

How often must a portable fire extinguisher be checked?

• a.Only after it is completely used up
• b.Only when the whole site closes down for typical light-duty operations
• c.Periodically, with an annual maintenance check✓
• d.Never once it has been installed

Under 29 CFR 1926.150, portable extinguishers must be inspected periodically and maintained, including an annual maintenance check. Monthly visual checks confirm they are charged and accessible. Neglected extinguishers may fail in an emergency.29 CFR 1926.150

Which is a recognized control for the caught-in hazard of a rotating auger or drilling equipment?

• a.Reaching into it while it rotates
• b.Removing all guards for more speed
• c.Guarding and keeping clothing, hair, and hands clear✓
• d.Wearing loose sleeves near the auger when working away from the edge

Rotating augers and drills can catch clothing and limbs, a caught-in/between hazard. Under 29 CFR 1926.300, moving parts must be guarded and workers keep clear. Loose clothing and jewelry must be avoided near rotating equipment.29 CFR 1926.300

A powered concrete saw or grinder should have which feature to reduce struck-by from the blade?

• a.A cracked blade for flexibility
• b.No guard, for better visibility provided the weather stays clear
• c.A guard removed to save weight
• d.A blade guard positioned to protect the operator✓

Under 29 CFR 1926.300 and 1926.303, abrasive wheels and saws must have guards that cover the spindle end and protect the operator from the wheel. Cracked or damaged wheels must not be used. Guards contain fragments if a wheel shatters.29 CFR 1926.303

Before an abrasive grinding wheel is mounted, it should be:

• a.Inspected and ring-tested for cracks✓
• b.Dropped on the floor to test it during the earlier phases of work
• c.Soaked in a solvent bath
• d.Painted over any visible cracks

Under 29 CFR 1926.303, abrasive wheels must be inspected and ring-tested before mounting to detect cracks. A cracked wheel can shatter at speed, a severe struck-by hazard. The guard and proper speed rating are also verified.29 CFR 1926.303

Hand and power tools must be maintained in what condition?

• a.Broken but held together with tape
• b.With their guards removed for speed
• c.Any condition, as long as they power on as long as the tools look intact
• d.Safe condition, with damaged tools removed from service✓

Under 29 CFR 1926.300, all hand and power tools must be maintained in a safe condition, whether owned by the employer or the worker. Damaged tools are removed from service. Guards must be kept in place during use.29 CFR 1926.300

What is a key safety rule when using a powder-actuated tool?

• a.Point it at coworkers to check the aim
• b.Only trained, certified operators may use it, and not in explosive atmospheres✓
• c.Anyone may use it without any training
• d.Use it in flammable vapor for convenience for most residential-scale jobs according to older industry practice

Under 29 CFR 1926.302, powder-actuated tools may be operated only by trained, certified employees and must not be used in explosive or flammable atmospheres. The tool must be tested each day before use. Misfires and ricochets are serious struck-by hazards.29 CFR 1926.302

When a load is being hoisted overhead, workers on the ground should:

• a.Stand directly beneath to guide it by hand when only one worker is involved
• b.Sleep in the drop zone during breaks
• c.Sit under it to rest in the shade
• d.Stay clear and never stand under the suspended load✓

Workers must never stand under a suspended load because rigging can fail, a top struck-by hazard. Under 29 CFR 1926.1425, workers are kept out of the fall zone except for limited tasks. Tag lines control the load from a safe distance.29 CFR 1926.1425

Which is required for emergency-response readiness on many construction sites?

• a.Only a suggestion box for workers
• b.A single phone with no numbers posted under most routine jobsite conditions
• c.No emergency planning is necessary
• d.A way to summon aid and trained first-aid providers or nearby medical care✓

Under 29 CFR 1926.50, employers must ensure medical personnel are available for advice and that first-aid providers or nearby clinics respond when no infirmary is close. Emergency numbers must be posted. Prompt care reduces injury severity.29 CFR 1926.50

When must eyewash or quick-drenching facilities be provided?

• a.Where workers may be exposed to injurious corrosive materials✓
• b.Never on any construction site
• c.Only inside office break rooms
• d.Only for occasional site visitors as some contractors interpret the rule

Under 29 CFR 1926.50(g), suitable facilities for quick drenching or flushing of the eyes and body must be provided where workers may be exposed to injurious corrosive materials. They allow immediate rinsing after a splash. They must be within quick reach.29 CFR 1926.50(g)

Illumination must be provided in work areas so that:

• a.Energy is saved by working in the dark when the crew is short on time
• b.Workers can see hazards and perform tasks safely✓
• c.Only supervisors are able to see
• d.The site looks attractive at night

Under 29 CFR 1926.56, construction areas must have minimum illumination levels so workers can see to work and recognize hazards. Poor lighting contributes to slips, trips, and struck-by incidents. Different areas have different minimum foot-candle levels.29 CFR 1926.56

What should a competent person do upon finding a hazardous condition in a trench?

• a.Add more spoil onto the trench edge
• b.Tell the workers to dig much faster
• c.Do nothing until the following month according to older industry practice
• d.Remove workers from the trench until it is corrected✓

Under 29 CFR 1926.651(k), when a competent person finds evidence of a possible cave-in, hazardous atmosphere, or other hazard, exposed workers must be removed until precautions are taken. Worker removal is immediate. Inspection has no value without action.29 CFR 1926.651(k)

When could a hazardous atmosphere require testing in an excavation?

• a.Only in trenches over 100 feet deep
• b.Only when the excavation is indoors
• c.Never, since trenches are open to air unless a supervisor decides otherwise
• d.In excavations over 4 feet deep where such an atmosphere could exist✓

Under 29 CFR 1926.651(g), atmospheres in excavations more than 4 feet deep must be tested where oxygen deficiency or hazardous atmospheres could exist, such as near landfills or where gases could enter. Ventilation and controls follow if needed. Heavier-than-air gases can pool in trenches.29 CFR 1926.651(g)

Which is a materials-handling control when using a powered industrial truck (forklift)?

• a.Give coworkers rides on the raised forks
• b.Let untrained workers operate the truck
• c.Do not exceed the rated capacity and keep the load low while traveling✓
• d.Carry loads as high as possible while driving for the majority of standard tasks

Powered industrial trucks must be operated within their rated capacity by trained operators, with loads carried low and tilted back. Under 29 CFR 1926.602, operators must be trained. Overloading and raised loads cause tip-overs and struck-by injuries.29 CFR 1926.602

Why must aisles and passageways be kept clear where mechanical handling equipment is used?

• a.To deliberately slow down the work
• b.To make the busy site look tidy
• c.To provide safe clearance and prevent struck-by and caught-between incidents✓
• d.To create room to store extra pallets based on the project's own schedule for typical light-duty operations

Under 29 CFR 1926.250, aisles and passageways must be kept clear and in good repair, with sufficient safe clearance where mechanical handling equipment operates. Blocked aisles force workers into the path of equipment. Clear routes reduce struck-by and caught-between risk.29 CFR 1926.250

A load chart on a crane provides which critical information?

• a.The available paint color options
• b.The current fuel price for the day
• c.The rated lifting capacity at various boom lengths and radii✓
• d.The operator's daily work schedule in the absence of a written program

The load chart shows the crane's rated capacity for different configurations of boom length, radius, and outrigger position. Operators must never exceed these values, per 29 CFR 1926.1417. Exceeding capacity leads to tip-overs and structural failure.29 CFR 1926.1417