Sheet 15Domain 2 of 5 · Hazard Identification and Control
Struck-by, caught-in, hand tools and PPE on a construction site
Nobody has noticed the bolt bag hanging off the beam over the gang box yet. Struck-by and caught-in hazards like that one show up on any ordinary walk, and OSHA counts both among its construction Focus Four, with falls and electrocution. Tools and personal protective equipment (PPE) share this sheet because a tool is where many of these hazards start.
Struck-by hazards come down to an object, a path and a person. The object can fly (a chip off a chisel with a mushroomed head), fall (a wrench off a scaffold plank), swing (a load turning on its hook) or roll (loose pipe on a slope). Caught-in hazards add a closing gap: an auger and its sleeve, an excavator's swing and a dump body, a trench wall and the worker below it.
The hierarchy of controls ranks the fixes, with PPE at the bottom. When gear is the right fix, the details matter: its rating, its fit, the standard it meets.
Several trades usually share the exposure. When one crew creates a struck-by hazard over another, OSHA's multi-employer worksite policy decides which contractors answer for it.
Talking point 02
Struck-by, caught-in and their neighbors
Struck-by
Injury from forcible contact with a moving object or piece of equipment: flying, falling, swinging or rolling.
Struck-against
The worker moves into the object, such as walking into an unprotected rebar end. Injury coding counts it apart from struck-by.
Caught-in or caught-between
Injury from being squeezed, caught or crushed between objects, or inside one, as in a trench collapse. The closing force does the harm rather than the impact.
Talking point 03
Spot the path, pick the fix
From the deck edge to the glove bin: guards, nailers, grinders, laydown areas, night work and gloves.
Card 1 of 19 · 0 right
Card 1
A laborer is steadying a steel beam by hand as a crane lowers it onto its column seats. What is the PRIMARY hazard to the laborer's hands?
Pick an answer. A short note for each option, A to D, appears here.
AA swinging load is a struck-by exposure to the body, while the hands on a landing beam face a closing gap.
BCorrect: A pinch point exists wherever a body part can be caught between a moving and a stationary object, as hands are between a landing beam and its seat.
CSharp mill edges can cut, but they are minor compared with the crushing force of a beam settling onto the column.
DThe rotating house is a swing-radius hazard for people beside the crane, not for a worker at the landing point.
Card 2
A worker will grind a weld flush with a handheld angle grinder, and the supervisor has issued a face shield. What else is required for the worker's eye protection?
Pick an answer. A short note for each option, A to D, appears here.
ATint addresses glare from welding light, not the flying particles that grinding throws.
BGrinding creates impact hazards rather than welding radiation, so a shade 10 helmet is unnecessary and limits visibility.
CCorrect: Face shields are secondary protectors and must be worn over primary eye protection such as safety glasses or goggles.
DA Z87.1 marking does not turn a face shield into primary eye protection, since particles can get under or around it.
Card 3
After a worker's hand was caught in the unguarded chain drive of a portable conveyor, which corrective action BEST prevents a recurrence?
Pick an answer. A short note for each option, A to D, appears here.
ACorrect: Exposed moving parts such as chains must be guarded, and a fixed guard keeps hands out regardless of worker behavior.
BGloves can be caught by a chain drive and pull the hand into it, so they add risk rather than removing it.
CRetraining depends on every worker staying alert, and it leaves the unguarded drive that caused the injury in place.
DPaint and signs warn about the hazard but do nothing to keep hands out of the chain drive.
Card 4
During a walkthrough, a supervisor finds pallets of concrete block stacked three high on soft, uneven ground beside a busy walkway. What is the BEST corrective action?
Pick an answer. A short note for each option, A to D, appears here.
ABanding pallets together does not correct a stack leaning on soft, uneven ground.
BCaution tape warns people away but leaves an unstable stack that can topple onto the walkway.
CCorrect: Materials stored in tiers must be stacked and secured so they cannot slide, fall or collapse, which starts with a firm, level base at a stable height.
DRerouting foot traffic accepts the unstable stack instead of fixing the footing that causes it to lean.
Card 5
At a toolbox talk, a crew reports that the ladder staging area forces them to carry ladders across a busy forklift route. What is the BEST response?
Pick an answer. A short note for each option, A to D, appears here.
ATelling workers to watch out relies on attention and leaves pedestrians crossing an active forklift route.
BSpotters add labor and still leave workers carrying ladders across forklift traffic.
CA toolbox topic is an administrative step that leaves the basic layout conflict in place.
DCorrect: Relocating the staging area removes the pedestrian-forklift crossing, which ranks higher in the hierarchy of controls than warnings or spotters.
Card 6
A framing crew's pneumatic nailers are set to contact-trip (bump) mode. Which change MOST reduces the risk of unintended nail discharge?
Pick an answer. A short note for each option, A to D, appears here.
ASafety glasses protect the eyes if a nail flies but do not prevent unintended discharge.
BLowering air pressure affects driving depth, not whether the tool bump-fires or double-fires.
CTraining helps, but it is an administrative control and weaker than an engineered trigger design.
DCorrect: A full sequential trigger fires only when the safety contact is pressed first and the trigger pulled second, preventing bump-fires and double-fires.
Card 7
A JHA for a concrete pump pour identifies the hazard of pressurized hose sections separating and whipping. Which control does 29 CFR 1926.702(e) require for this hazard?
Pick an answer. A short note for each option, A to D, appears here.
ADischarge pipe supports must be designed for a 100 percent overload, so 50 percent understates the requirement.
BAn operator's judgment of pressure is not an engineered control and does not keep hose sections joined.
CFace shields and hard hats do not stop a whipping hose from striking workers.
DCorrect: Compressed air hoses on concrete pumping systems must have positive fail-safe joint connectors so sections cannot separate under pressure.
Card 8
Which of the following hazard controls is considered most effective according to the hierarchy of controls?
Pick an answer. A short note for each option, A to D, appears here.
ACorrect: Elimination removes the hazard from the workplace entirely, so workers cannot be exposed to it at all.
BAdministrative controls change how people work, which makes them depend on behavior and rank below elimination.
CPPE is the last line of defense because it protects only the wearer and only when used correctly.
DWarning signs inform people about a hazard but leave it in place, which ranks them well below elimination.
Card 9
Framers are working on a second-floor deck while electricians work directly below. Tools have been knocked off the open deck edge twice this week. Which measure is the MOST effective protection for the electricians?
Pick an answer. A short note for each option, A to D, appears here.
ACorrect: Toeboards or screens stop tools and materials at the edge, protecting everyone below rather than relying on warnings.
BSigns warn people about overhead work but do nothing to keep objects from falling off the deck.
CVerbal warnings depend on timing and attention, and two drops have already happened this week.
DHard hats are still required but only reduce injury after something strikes; they do not keep objects from falling.
Card 10
Before issuing chemical-resistant gloves for a job using a new epoxy thinner, where should the supervisor get the BEST guidance on glove material?
Pick an answer. A short note for each option, A to D, appears here.
AA glove that resisted one solvent may be permeated quickly by another, so past use is not a valid guide.
BCut-resistance ratings measure mechanical protection only and say nothing about chemical permeation.
CCorrect: Glove protection is chemical-specific, so SDS Section 8 and permeation data for that exact chemical identify the right material and change-out time.
DNitrile resists many chemicals but fails against some ketones and chlorinated solvents, so it cannot be assumed.
Card 11
A supervisor sees a carpenter ripping plywood on a jobsite table saw with the blade guard removed because it gets in the way. What should the supervisor do?
Pick an answer. A short note for each option, A to D, appears here.
ACorrect: Guards must stay in place on tools designed to use them, so cutting stops until the table saw's guard is reinstalled and working.
BA face shield and gloves do not prevent blade contact or kickback, and gloves near a blade can be pulled in.
CCoaching later leaves the carpenter exposed to blade contact and kickback for the rest of the cutting.
DA push stick supplements the guard but does not replace it, so blade exposure and kickback risk remain.
Card 12
On a tight urban site, material deliveries arrive with no staging plan, and loads are being set down in walkways and exit paths. What is the BEST corrective action?
Pick an answer. A short note for each option, A to D, appears here.
ASigns warn about materials in walkways but accept blocked exits instead of preventing them.
BCorrect: A delivery and laydown plan with set staging areas prevents materials from landing in walkways and exits in the first place.
CNight deliveries shift the timing of the problem without deciding where loads will be placed.
DClearing walkways after each delivery is reactive and leaves exits blocked between cleanups.
Card 13
A telehandler must carry bundles of conduit through a narrow corridor where electricians are working on ladders. What is the BEST way to control the struck-by hazard?
Pick an answer. A short note for each option, A to D, appears here.
ACarrying a load high raises the center of gravity and increases tip-over risk; loads travel low.
BCorrect: Separating pedestrians from moving equipment is the strongest layout control when there is no room to pass safely, so the corridor is cleared for the move.
CA backup alarm only warns, and workers on ladders in a narrow corridor may not be able to get clear.
DA horn warns people who may be unable to react in time from a ladder in a tight space.
Card 14
Before a worker mounts a new wheel on a 4½-inch angle grinder, which check BEST prevents injury from the wheel bursting?
Pick an answer. A short note for each option, A to D, appears here.
AThin cut-off wheels are not designed for side loading, and side grinding with them can cause a burst.
BRemoving the guard is a common cause of serious face and hand injuries when a wheel shatters.
COvertightening the flange nut can crack the wheel and set up the very failure the check is meant to prevent.
DCorrect: A wheel run faster than its rated speed can burst, so its marked maximum speed must equal or exceed the grinder's no-load RPM.
Card 15
Ironworkers will be bolting deck overhead while an electrical crew pulls wire on the floor directly below. What is the BEST action for the controlling contractor's supervisor?
Pick an answer. A short note for each option, A to D, appears here.
AUnder multi-employer rules the controlling contractor must coordinate hazards one crew creates for another, so leaving each foreman to his own crew misses the overhead exposure.
BHard hats reduce injury from small falling objects but will not stop a dropped bolt bag or steel piece; PPE is the last line, not a substitute for separation.
CA caution sign is only a warning, the weakest measure here, and does nothing to keep falling objects off the electricians below.
DCorrect: Keeping workers out from under overhead work removes the exposure entirely, which ranks above PPE and warnings in the hierarchy of controls.
Card 16
Before a crew uses a portable belt conveyor to move roofing materials, a supervisor checks it for caught-in hazards. Where are nip points MOST likely?
Pick an answer. A short note for each option, A to D, appears here.
ABetween rollers the belt runs in a straight span with no converging surfaces, so the in-running nip hazard is low there.
BThe control box presents electrical hazards and should be closed and grounded, but it creates no caught-in point.
CFixed frame members do not move, so they pose bump or contact hazards rather than caught-in hazards.
DCorrect: In-running nip points form where a moving belt converges with a pulley or roller, which is why those points must be guarded.
Card 17
A crew is breaking out a concrete slab with a jackhammer beside a walkway used by other trades. Which measure BEST protects the other trades from flying chips?
Pick an answer. A short note for each option, A to D, appears here.
ASigns rely on people noticing and still route them through the debris zone.
BCorrect: Screening the work and moving the walkway separates people from flying chips, which ranks above signs, timing, and PPE.
CSafety glasses protect only the eyes of those who wear them and leave the rest of the body exposed to chips.
DWorking during low traffic still leaves some people passing through the debris zone.
Card 18
Workers are handling sheet-metal ductwork with sharp, unfinished edges. Which hand protection should the supervisor select?
Pick an answer. A short note for each option, A to D, appears here.
ARubber insulating gloves are electrical PPE and are damaged by sharp material.
BCotton knit gloves give grip but slice easily on sharp sheet metal.
CDisposable nitrile gloves protect against some chemicals but offer little cut resistance.
DCorrect: PPE is matched to the specific hazard, so sharp edges call for gloves rated for cut resistance.
Card 19
A crew will place a concrete deck at night. What is the BEST way for the supervisor to control hazards caused by poor visibility?
Pick an answer. A short note for each option, A to D, appears here.
AAdding lights only after complaints means crews work in the dark until someone speaks up.
BHeadlamps light only where the worker is looking and do not show edges, openings, or equipment paths.
CExperience does not overcome the inability to see hazards.
DCorrect: Area lighting for work zones and travel paths, set up before work starts, lets workers and operators see hazards from the outset.
Talking point 04
PPE by body part
Construction PPE rules in 29 CFR 1926 Subpart Escroll →
Body part
Rule
What to check
Head
29 CFR 1926.100
Hard hat meeting ANSI Z89.1. Type I protects the top, Type II the top and sides; Class E for possible electrical contact, Class C gives no electrical protection
Eyes and face
29 CFR 1926.102
Protection meeting ANSI Z87.1, chosen for the hazard: impact, splash, dust, glare or radiant energy