COHN Ergonomics and Physical Hazards 5 — Questions and Answers
Question 1: A COHN is conducting a walkthrough of a cold storage facility (-10°F). Which physiological response to cold stress should be monitored as an early warning sign?
- Hyperthermia
- Cessation of shivering with declining core temperature (Correct answer)
- Profuse sweating
- Rapid heart rate above 140 bpm
Correct answer: Cessation of shivering with declining core temperature
When shivering stops in a cold environment, it signals that the body can no longer maintain heat production and core temperature is falling — a sign of impending hypothermia.
Question 2: Which ergonomic principle does a footrest under a desk primarily address?
- Reducing lumbar lordosis by tilting the pelvis anteriorly
- Providing lower extremity support to reduce pressure on the thighs and improve seated posture (Correct answer)
- Absorbing floor vibration transmitted to the worker
- Preventing contact stress on the dorsal foot
Correct answer: Providing lower extremity support to reduce pressure on the thighs and improve seated posture
A footrest supports workers whose feet do not reach the floor, relieving thigh pressure from the seat edge and reducing lower back fatigue in seated tasks.
Question 3: OSHA's Noise standard (29 CFR 1910.95) requires a hearing conservation program when TWA noise exposure equals or exceeds:
- 80 dBA
- 85 dBA (Correct answer)
- 90 dBA
- 95 dBA
Correct answer: 85 dBA
The OSHA action level triggering a mandatory hearing conservation program (audiometric testing, training, and hearing protectors) is an 8-hour TWA of 85 dBA.
Question 4: A supermarket cashier scans items using a wrist-flexed, ulnar-deviated grip. This wrist posture primarily increases risk for:
- Trigger finger (stenosing tenosynovitis)
- Cubital tunnel syndrome
- Carpal tunnel syndrome due to increased carpal tunnel pressure (Correct answer)
- Lateral epicondylitis
Correct answer: Carpal tunnel syndrome due to increased carpal tunnel pressure
Wrist flexion and ulnar deviation elevate pressure within the carpal tunnel, compressing the median nerve and increasing risk of carpal tunnel syndrome.
Question 5: When evaluating ergonomic interventions, which metric is MOST meaningful for demonstrating program effectiveness to management?
- Number of ergonomic assessments completed
- Reduction in musculoskeletal disorder (MSD) incidence rates and lost workday cases (Correct answer)
- Amount spent on ergonomic equipment
- Number of ergonomic training sessions conducted
Correct answer: Reduction in musculoskeletal disorder (MSD) incidence rates and lost workday cases
Reduction in MSD incidence rates and lost workday cases directly demonstrates health outcomes and business value, making them the most compelling metrics for management reporting.
Question 6: A non-ionizing radiation hazard from UV radiation in a welding environment is primarily controlled through which PPE?
- Supplied-air respirator
- Filtered welding helmet with appropriate shade number (Correct answer)
- Chemical-resistant gloves
- Thermal insulating suit
Correct answer: Filtered welding helmet with appropriate shade number
Welding arcs emit intense UV, visible, and infrared radiation; a welding helmet with an appropriately shaded lens filter is the primary PPE for protecting eyes and face.
Question 7: An ergonomics team applies the Hierarchy of Controls to a repetitive motion task. Placing workers on a rotation schedule is classified as which type of control?
- Elimination
- Engineering control
- Administrative control (Correct answer)
- PPE
Correct answer: Administrative control
Job rotation is an administrative control that manages worker exposure time rather than changing the physical hazard itself.
COHN Ergonomics and Physical Hazards 5
A COHN is conducting a walkthrough of a cold storage facility (-10°F).
Which physiological response to cold stress should be monitored as an early warning sign?