Focus Four: Struck-By and Caught-In or -Between Hazards

Focus Four: Struck-By and Caught-In or -Between Hazards

OSHA identifies four hazard categories responsible for the majority of construction fatalities. This lesson covers two of them: struck-by and caught-in or -between. Electricians encounter both categories every day—on active roadways, around heavy equipment, under overhead loads, and inside mechanical rooms. Knowing how to recognize these hazards and select the right controls is a core OSHA 30 competency.

Struck-By Hazards

A struck-by hazard exists any time a worker can be hit by a moving object. OSHA groups them into four types:

1. Struck by flying objects. Power tools, grinding discs, and nail guns can propel debris at high speed. A conduit being cut can kick back chips or blade fragments. Always wear safety glasses or a face shield rated for the task. Inspect tool guards before use and never remove them.

2. Struck by falling objects. Materials stored on elevated surfaces, unsecured tools on ladders, and loads suspended by cranes or aerial lifts can fall onto workers below. Controls include toe boards on scaffolding, tool tethers, hard hats rated at minimum ANSI Type I Class E for electrical work, and exclusion zones directly beneath overhead work.

3. Struck by swinging or sliding loads. A load on a crane or forklift can swing when the machine turns or stops. Never stand in the swing radius of a crane. Tag lines control load movement; workers must never use their hands to stop a swinging load.

4. Struck by vehicles. This is the leading struck-by cause of death in construction. Electricians pulling underground service in roadways, setting service equipment near parking lots, or working on highway lighting are at serious risk. Controls include:

• High-visibility (hi-vis) apparel meeting ANSI/ISEA 107 Class 2 or Class 3 requirements (choose Class 3 near roadways with traffic moving faster than 25 mph).
• Proper traffic control: cones, barricades, flaggers, and advance warning signs set up before work begins.
• Positioning yourself so you can always see approaching traffic.
• Never turning your back to live traffic without a spotter.

Caught-In or -Between Hazards

A caught-in or -between hazard occurs when a worker's body or clothing is caught, squeezed, crushed, or pinched between objects.

Trench and excavation collapse. Electricians install underground conduit, grounding electrodes, and service laterals in excavations. Soil can collapse without warning. OSHA requires protective systems—sloping, shoring, or trench boxes—in excavations 5 feet deep or more (and sometimes shallower in unstable soil). Never enter an unprotected trench. A competent person must classify the soil and inspect the excavation daily.

Rotating equipment and machinery. Panel work near HVAC units, generators, and pump motors exposes electricians to rotating shafts, belts, pulleys, and fan blades. Machine guards are the primary control. Do not reach past a guard or remove one for convenience. Before working on or adjusting equipment with rotating parts, apply lockout/tagout (LOTO) per OSHA 29 CFR 1910.147 to de-energize and isolate the machine. Verify zero energy before touching internal components.

Pinch points. A pinch point is any place where a part of the body can be caught between a moving part and a stationary surface. Common examples on electrical jobs include conduit benders, wire reels under tension, and vehicle tailgates during material deliveries. Wear properly fitting gloves (not loose), keep fingers clear of the bite point on benders, and stand to the side of a wire reel under load.

Caught between stationary objects. Working in tight spaces—pulling wire through a congested cable tray or squeezing past structural steel—creates crush and pinch risk even with no moving machinery. Plan the work path before entering confined or congested areas.

Hierarchy of Controls Applied to Focus Four

For every struck-by or caught-in hazard, apply the hierarchy of controls in order:

1. Elimination – remove the hazard (reschedule work when crane is not operating).

2. Substitution – use a safer method (pull wire with a tugger instead of by hand near rotating parts).

3. Engineering controls – guarding, trench boxes, barricades.

4. Administrative controls – exclusion zones, signage, spotter assignments, LOTO procedures.

5. PPE – hi-vis vest, hard hat, safety glasses, gloves. PPE is the last line of defense, never the first.

Setting Up a High-Visibility Work Zone for Street-Side Electrical Work

When working at a pad-mounted transformer or pulling wire in a conduit run along a street:

1. Obtain the required permits and a traffic control plan before setup.

2. Place advance warning signs at distances specified by the Manual on Uniform Traffic Control Devices (MUTCD) for your road speed and work type.

3. Set cones to channel traffic away from the work area, creating a buffer zone between the lane and your workers.

4. Assign a trained flagger if traffic lanes must be reduced.

5. All workers inside the traffic control zone wear Class 2 or Class 3 hi-vis vests.

6. Orient your body so you can monitor traffic. Use a spotter when your view is blocked.

Key Reminders

• Hard hat, hi-vis vest, and eye protection are non-negotiable PPE in any struck-by environment.
• Never enter an unprotected excavation regardless of depth if soil is unstable.
• LOTO before working near any rotating or moving part.
• The swing radius of a crane and the area directly under a suspended load are exclusion zones—stay out.
• Report unguarded machinery and missing trench protection to your supervisor immediately.