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Course 807: Focus Four - Caught-In or -Between Hazards

Safety guides and audits to make your job as a safety professional easier

Protecting Yourself from Caught-In or –Between Hazards

Use Properly Guarded Machinery

Never remove a safety guard when a tool is being used. Hazardous moving parts of power tools and equipment need to be safeguarded. Some examples of parts that need to be guarded are:

  • belts;
  • gears;
  • shafts;
  • pulleys;
  • sprockets;
  • spindles;
  • drums;
  • flywheels;
  • chains; or
  • other reciprocating, rotating;
  • or moving parts of equipment must be guarded if such parts are exposed to contact by workers.

It is also important to note protective clothing and equipment can create hazards. A protective glove can become caught between rotating parts, or a respirator face piece that hinders the wearer's vision, for example, requires alertness and continued attentiveness whenever they are used.

Other parts of the worker's clothing may present additional safety hazards. For example, loose-fitting shirts might become entangled in rotating spindles or other kinds of moving machinery. Jewelry, such as bracelets and rings, can catch on machine parts or stock and lead to serious injury by pulling a hand into the danger area.

Provide Guards on Power Tools and other Equipment with Moving Parts

OSHA standards require your employer to ensure hand-held power tools are fitted with guards and safety switches. The type of guard will be determined by the power source of the tool (electric, pneumatic, liquid fuel, hydraulic, or powder-actuated). Exposed moving parts of power tools, such as belts, gears, shafts, pulleys, etc. must be guarded. Points-of-operation, where the work is actually performed on the materials, must also be guarded. Power saws are a primary type of equipment which requires a point-of-operation guard. In-running nip points, such as where the sanding belt runs onto a pulley in a belt sanding machine, must also be guarded.

Guards are also required on other equipment with moving parts, such as chain drives on cranes, to which workers may be exposed.

Other Methods to Secure Machinery

Make sure your equipment is de-energized and cannot be started accidentally. First, disconnect tools when not in use, before servicing, and when changing accessories such as blades, bits, and cutters. Turn off vehicles before you do maintenance or repair work. If possible, lockout the power source to the equipment. The type of power source may be electric, pneumatic, liquid fuel, hydraulic, or powder-actuated. Lower or block the blades of bulldozers, scrapers, and similar equipment before you make repairs or when the equipment is not in use.

Your employer should provide a lock-out/tag-out program or equivalent system to ensure equipment is not accidentally energized during maintenance or repair. Lockout/tagout procedures are specifically required for equipment used in concrete and masonry operations. Bulldozer and scraper blades, end loader buckets, dump bodies, and similar equipment must be blocked or fully lowered when being repaired or not in use.

Designate a Competent Person

OSHA defines a “competent person” as:

“one who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them.”

Your employer must designate a competent person for certain construction activities that may have caught-in or-between hazards:

  • training for scaffold erection
  • inspections of excavations, the adjacent areas, and protective systems
  • engineering survey prior to demolition of a structure (and any adjacent structure where workers may be exposed) to determine the condition of the framing, floors, and walls, and possibility of unplanned collapse
  • continuing inspections during demolition to detect hazards resulting from weakened or deteriorated floors, or walls, or loosened material

Crushed-by Heavy Equipment

The best way to prevent workers from being crushed by heavy equipment that tips over is to prevent the equipment from tipping over in the first place. For example, cranes can tip over if the load capacity is exceeded, or the ground is not level or too soft. OSHA requires your employer to designate a competent person to inspect crane operations to identify hazardous working conditions, including ensuring the support surface is firm and able to support the load. Your employer must also make sure the material handling equipment is equipped with rollover protective structures. OSHA standards require motor vehicles, forklifts, and earthmoving equipment to be equipped with seat belts. Your employer must require their use. The use of seat belts will prevent workers from being thrown from a vehicle or equipment and being crushed when the vehicle or equipment tips over.

Crushed-by Collapsing Walls

During demolition, your employer must ensure any stand-alone wall more than one story must have lateral bracing unless the wall was designed to be stand-alone and is otherwise in a safe condition to be self-supporting.

Jacks must have a firm foundation. If necessary, the base of a jack must be blocked or cribbed. After a load has been raised, it must be cribbed, blocked, or otherwise secured at once.

Pinned Between Equipment, Materials, or other Objects

To protect yourself from being pinned between equipment, materials, or objects you must:

  • be aware at all times of the equipment around you and stay a safe distance from it;
  • never place yourself between moving materials and an immovable structure, vehicle, or stacked materials;
  • make sure all loads carried by equipment are stable and secured;
  • stay out of the swing radius of cranes and other equipment; and
  • wear a seatbelt, if required, to avoid being thrown from a vehicle and then potentially being crushed by the vehicle if it tips over.

Your employer is required to take measures to prevent workers from being pinned between equipment and a solid object, such as a wall or another piece of equipment; between materials being stacked or stored and a solid object, between shoring and construction materials in a trench.

Other example situations are:

  • During demolition operations, when balling or clamming is being performed, only the personnel absolutely necessary to the work must be allowed in the work area.
  • Your employer must make sure that proper bracing is used between heavy plates used as shoring in a trench.
  • Your employer must carefully arrange the path of travel when loading/unloading, stacking, and storing materials so that no workers will be caught between materials and moving equipment or between materials and a wall.

Pinned Between Equipment, Materials, or other Objects (Continued...)

Hazardous Energy in the Workplace: A Recent Accident

The son of the owner of a commercial drywall construction company, an employee of the company, was preparing an aerial lift for a job and had replaced two battery terminals. He had raised the aerial boom and was reaching toward the battery compartment across the metal enclosure that houses the lift's toggle controls when the boom dropped and pinned him to the control panel. His father discovered him and summoned emergency responders, but he died at the site.

Image of a person pinned by a scissor lift

Investigation Findings

  1. The lift's emergency valve, hydraulic hoses and fittings, and electrical wiring were inspected after the accident and were not defective; however, the on/off key switch had been bypassed so that the operator could use the toggle switches without using the key.
  2. The battery charging system was missing a fuse that would stop the system from charging, and the spring-loaded toggle switches that controlled the boom did not have guards to prevent accidental contact.
  3. The employee did not use lockout procedures while he was working on the lift and did not block the boom to prevent it from dropping.
  4. The owner had not reviewed the lift's instruction manual with the victim or other company employees.
  5. Although the company had more than 10 employees, it did not have a safety committee.

The accident resulted in the OSHA violations listed below:

  1. The employer failed to ensure that employees did not remove or tamper with required safety devices.
  2. The employer did not develop, document, and require employees to use lockout procedures to control hazardous energy during maintenance work.
  3. The employer had more than 10 employees but did not have a safety committee.(State of Oregon requirement)

Excavation Sites

To protect yourself on an excavation site you must:

  • not work in an unprotected trench five feet deep or more. The type of protection may be one of the following:
  • Enter or exit a trench or excavation only by using a ladder, stairway or properly designed ramp that is placed within the protected area of the trench.
  • Do not work outside of the confines of the protection system!

Excavation Sites (Continued...)

OSHA standards on trenching and excavation require your employer to designate a competent person to inspect the trenching operations. The competent person must be trained in and knowledgeable about soils classification, the use of protective systems, and the requirements of the OSHA standard. The competent person must be capable of identifying hazards, and authorized to immediately eliminate hazards.

Your employer must make sure all excavations and trenches five feet deep or more, but less than 20 feet, are protected by sloping or benching, trench box or shield, or shoring. There must also be adequate means of access and egress from the excavation. If an excavation is more than 20 feet deep, a professional engineer must design the system to protect the workers.

You must be protected from equipment or materials that could fall or roll into excavations. This could include spoils that could fall into the trench and bury the workers. Mobile equipment used near or over an excavation presents a hazard. A warning system must be utilized (such as barricades, hand or mechanical signals, or stop logs), when mobile equipment is:

  • operated next to an excavation or
  • is required to approach the edge of an excavation, and
  • the operator does not have a clear and direct view of the edge of the excavation. If possible, the grade should be away from the excavation.

If a crane or earthmoving equipment is operating directly over the top of a trench, workers should not be working underneath.

Buried-by Structures

Measures need to be taken by your employer to avoid the collapse of other structures, such as scaffolds, that could bury workers underneath them. Anytime there is inadequate support, improper construction, or a shift in the components of a scaffold (including the base upon which the structure is built); there is danger of collapse. Cinder blocks or other similar materials should not be used to support a scaffold because they could be crushed. OSHA standards require that scaffolds can only be erected, moved, dismantled or altered under the supervision of a competent person. The competent person selects and directs the workers who erect the scaffold. The selected workers must be trained by a competent person on correct procedures and hazards of scaffold erection.


Make sure you have the proper training on the equipment and hazards of your job so you can work safely. Specific and detailed training is a crucial part of any effort to safeguard employees from worksite hazards.

OSHA’s general training requirement for construction workers is:

The employer shall instruct each employee in the recognition and avoidance of unsafe conditions and the regulations applicable to his work environment to control or eliminate any hazards or other exposure to illness or injury.

Your employer must train you to perform your job and use the provided equipment safely. If working with scaffolding your employer should be aware of specific training requirements found in OSHA standards. These standards can be found in 29 CFR 1926.454 (Scaffolds – workers who are involved in erecting, disassembling, moving, operating, repairing, maintaining, or inspecting a scaffold).


Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. You must answer all of the questions before submitting the quiz.

Good luck!

1. Caught in or -between hazards are related with excavations [trenches]; therefore, the hazard considered to be the greatest risk is _____.

2. One who is capable of identifying existing and predictable hazards in the surroundings, or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them is a/n _____.

3. Providing worker training on the safe use of the equipment being operated is the responsibility of the _____.

4. Workers should not work in an unprotected trench that is 5 feet deep or more. The type of protection installed may be sloping or benching; trench box or shield; and _____.

5. To prevent being pinned between equipment and other objects, workers should avoid _____.

Have a great day!

Important! You will receive an "error" message unless all questions are answered.