Environmental Ergonomics Flashcards
7 cards from real CES practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Environmental Ergonomics flashcards as text
The EU Physical Agents (Vibration) Directive sets a daily exposure action value (EAV) for whole-body vibration (WBV) at:
Answer: 0.5 m/s²
The EU Vibration Directive sets the daily EAV for WBV at 0.5 m/s² A(8), above which employers must introduce risk reduction measures.
In ergonomic lighting design, what is the purpose of using task lighting in addition to ambient (general) lighting?
Answer: To provide targeted higher illuminance at specific work surfaces without over-lighting the entire space
Task lighting supplements ambient lighting by delivering higher illuminance exactly where precision work is performed, improving visual comfort without requiring high ambient levels throughout.
Relative humidity in an office environment is ideally maintained in which range to balance occupant comfort and minimize health complaints?
Answer: 30–60%
ASHRAE recommends 30–60% relative humidity to prevent dry mucous membranes at low humidity and mold/respiratory irritation at high humidity.
Which control measure is the most effective ergonomic intervention for reducing whole-body vibration exposure in vehicle operators?
Answer: Installing a suspension seat with a low-transmissibility rating
A suspension seat engineered to isolate the occupant from vehicle vibration is the primary engineering control for WBV, directly reducing the energy transmitted to the spine.
An ergonomist discovers that workers near a noisy machine experience noise levels of 95 dBA. Under OSHA's noise standard (29 CFR 1910.95), what is the maximum permissible exposure duration at this level?
Answer: 4 hours
OSHA's permissible exposure table allows a maximum of 4 hours at 95 dBA before the daily dose reaches 100% and engineering controls or HPDs are required.
The 'thermal comfort zone' described in ASHRAE Standard 55 is primarily determined by which combination of factors?
Answer: Operative temperature, humidity, air speed, and clothing/activity levels
ASHRAE 55 defines thermal comfort as a function of operative temperature, relative humidity, air speed, metabolic rate, and clothing insulation (clo).
Which indoor air pollutant is most commonly associated with 'sick building syndrome' and is primarily emitted from building materials, furniture, and adhesives?
Answer: Volatile organic compounds (VOCs)
VOCs off-gassed from paints, carpets, adhesives, and furnishings are a primary contributor to sick building syndrome symptoms such as headaches, eye irritation, and fatigue.