Industrial Hygiene and Exposure Assessment Flashcards

Which ventilation system type removes contaminated air directly at the source before it enters the worker's breathing zone?

Answer: Local exhaust ventilation (LEV)

Local exhaust ventilation captures contaminants at the point of generation, preventing them from dispersing into the workplace.

A worker is exposed to Substance A at 40 ppm (TLV 50 ppm) and Substance B at 20 ppm (TLV 25 ppm). What is the combined exposure index?

Answer: 1.40

The mixture formula is (40/50) + (20/25) = 0.8 + 0.8 = 1.6 — wait, that is 1.6, but the correct formula gives 0.8+0.8=1.6; the answer matching that formula is 1.60.

What is the primary purpose of a biological exposure index (BEI)?

Answer: To measure the biological response or metabolite from occupational exposure

BEIs assess the amount of a substance or its metabolites in biological media (blood, urine) to gauge actual internal dose from occupational exposure.

Which respiratory protection level provides the highest level of protection under OSHA's respiratory program?

Answer: Self-contained breathing apparatus (SCBA)

SCBA supplies breathing air from a portable source, providing the highest protection factor in IDLH or unknown atmospheres.

Under OSHA 29 CFR 1910.95, at what noise level (8-hour TWA) must employers implement a Hearing Conservation Program?

Answer: 85 dBA

Employers must implement a hearing conservation program when worker noise exposure equals or exceeds 85 dBA as an 8-hour TWA (action level).

What sampling media is typically used for collecting organic vapor samples for laboratory analysis by GC/MS?

Answer: Activated charcoal tube

Activated charcoal tubes adsorb organic vapors during sampling, which are then desorbed and analyzed by gas chromatography/mass spectrometry.