CES Environmental Ergonomics 2

Question 1

The EU Physical Agents (Vibration) Directive sets a daily exposure action value (EAV) for whole-body vibration (WBV) at:

Accepted Answer

0.5 m/s²

Answer

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.

Question 2

In ergonomic lighting design, what is the purpose of using task lighting in addition to ambient (general) lighting?

Accepted Answer

To provide targeted higher illuminance at specific work surfaces without over-lighting the entire space

Answer

Task lighting supplements ambient lighting by delivering higher illuminance exactly where precision work is performed, improving visual comfort without requiring high ambient levels throughout.

Question 3

Relative humidity in an office environment is ideally maintained in which range to balance occupant comfort and minimize health complaints?

Accepted Answer

30–60%

Answer

ASHRAE recommends 30–60% relative humidity to prevent dry mucous membranes at low humidity and mold/respiratory irritation at high humidity.

Question 4

Which control measure is the most effective ergonomic intervention for reducing whole-body vibration exposure in vehicle operators?

Accepted Answer

Installing a suspension seat with a low-transmissibility rating

Answer

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.

Question 5

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?

Accepted Answer

4 hours

Answer

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.

CES - Certified Ergonomic Specialist Practice Test

CES - Certified Ergonomic Specialist Practice Test

CES Environmental Ergonomics 2