CPE Environmental Ergonomics Questions and Answers Flashcards

OSHA's permissible exposure limit (PEL) for occupational noise is 90 dBA as an 8-hour TWA with what exchange rate?

Answer: 5 dB doubling rate

OSHA's PEL uses a 5 dB exchange rate (time-intensity trade-off), allowing 95 dBA for 4 hours or 100 dBA for 2 hours as exposure doubles.

Wet Bulb Globe Temperature (WBGT) is used to assess heat stress and accounts for which environmental factors?

Answer: Air temperature, humidity, radiant heat, and air movement

WBGT combines natural wet bulb (humidity/evaporation), black globe (radiant heat), and dry bulb (air temperature) measurements to characterize total thermal stress.

Which type of lighting is most recommended for detailed visual inspection tasks in industrial settings?

Answer: High-intensity task lighting supplemented by appropriate ambient lighting

Detailed inspection tasks require high-intensity task lighting targeted at the work surface, supplemented by adequate ambient lighting to minimize contrast discomfort.

What is the recommended ASHRAE thermal comfort temperature range for sedentary office work in summer?

Answer: 73–79°F (23–26°C)

ASHRAE Standard 55 recommends an operative temperature range of approximately 73–79°F (23–26°C) for sedentary office occupants in summer conditions.

Noise-Induced Hearing Loss (NIHL) first affects which frequency range?

Answer: 4,000 Hz (4 kHz notch)

NIHL characteristically presents first as a 'notch' at 4,000 Hz on the audiogram before spreading to adjacent frequencies with continued exposure.

Glare in visual ergonomics is classified as either disability glare or discomfort glare. Which type directly reduces visual acuity?

Answer: Disability glare

Disability glare directly impairs visual acuity by scattering light across the retina, reducing contrast and the ability to distinguish details.