CHST Struck-by and Caught-in/Between Hazards — Questions and Answers
Question 1: A worker is directing a crane operator near an active roadway. Which struck-by hazard control is considered the hierarchy's first priority?
- Establish a barricaded exclusion zone that eliminates worker exposure to the swing radius (Correct answer)
- Issue the worker a high-visibility vest and hard hat
- Brief the worker on hand signal procedures
- Reduce crane load weight to lower impact risk
Correct answer: Establish a barricaded exclusion zone that eliminates worker exposure to the swing radius
Elimination/substitution sits at the top of the hierarchy of controls. Establishing a physical exclusion zone removes workers from the hazard area entirely, which is more effective than PPE or administrative controls that rely on human behavior.
Question 2: Under OSHA 29 CFR 1926, what is the minimum safe distance workers on foot must maintain from the path of a swinging crane load unless otherwise protected?
- 6 feet
- 10 feet (Correct answer)
- 15 feet
- The load's maximum radius plus 2 feet
Correct answer: 10 feet
OSHA 29 CFR 1926.1425 requires workers to stay at least 10 feet away from the path of a swinging crane load or be protected by a physical barrier. This prevents struck-by injuries from load swing or dropped material.
Question 3: Which of the following best describes a 'caught-in/between' fatality mechanism?
- A worker struck by a nail gun discharge from 20 feet away
- A worker's hand compressed between a rotating auger and a fixed guard (Correct answer)
- A worker falling from an unguarded floor opening
- A worker electrocuted by a live conductor
Correct answer: A worker's hand compressed between a rotating auger and a fixed guard
Caught-in/between hazards occur when a body part is caught, compressed, or crushed between objects. A rotating auger and a fixed surface is a classic caught-in/between scenario. The other options describe struck-by, fall, and electrocution hazards respectively.
Question 4: A concrete pump hose whips free under pressure and strikes a worker. This is classified as which OSHA Fatal Four hazard type?
- Caught-in/between
- Fall
- Struck-by (Correct answer)
- Electrocution
Correct answer: Struck-by
A pressurized hose whipping and hitting a worker is a struck-by event — the worker is hit by a moving object with force. OSHA's struck-by category includes projectiles, flying objects, and moving equipment/materials.
Question 5: What is the most effective control to protect workers from being struck by vehicles in an active construction work zone?
- Requiring all workers to wear orange safety vests
- Posting 'Workers Present' signage on approach roads
- Physical separation of worker zones from vehicle travel paths using concrete barriers or k-rail (Correct answer)
- Scheduling vehicle deliveries during shift breaks
Correct answer: Physical separation of worker zones from vehicle travel paths using concrete barriers or k-rail
Physical barriers (engineering controls) provide positive separation between workers and moving vehicles, eliminating the hazard regardless of worker attention or driver behavior. High-vis vests (PPE) and signage (administrative) are lower on the hierarchy and depend on human compliance.
Question 6: A worker is cleaning beneath a suspended load while the crane operator takes a break. Which OSHA principle does this violate?
- Operators must remain at the controls whenever a load is rigged
- Workers must never work beneath a suspended load
- Loads must be lowered before the operator leaves the cab
- All of the above (Correct answer)
Correct answer: All of the above
All three principles apply: OSHA 1926.1417 requires operators to remain at controls with a suspended load; 1926.1425 prohibits working under suspended loads; and loads should be lowered or otherwise secured before an operator steps away. Violating any one of these creates a struck-by or crushing hazard.
CHST Struck-by and Caught-in/Between Hazards
A worker is directing a crane operator near an active roadway.
Which struck-by hazard control is considered the hierarchy's first priority?