Industrial Hygiene & Exposure Monitoring Flashcards
6 cards from real CESCO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Industrial Hygiene & Exposure Monitoring flashcards as text
In industrial hygiene, what is the purpose of calculating the 'hazard ratio' (HR) or 'exposure ratio' (ER)?
Answer: To compare measured exposure to the occupational exposure limit and determine if limits are exceeded
The hazard ratio (measured exposure ÷ OEL) indicates whether exposures are below, at, or above acceptable limits; values ≥1 indicate a potential overexposure requiring action.
Which sampling media is most appropriate for collecting volatile organic compounds (VOCs) during personal air monitoring?
Answer: Activated charcoal sorbent tube with thermal desorption or solvent extraction
Activated charcoal tubes efficiently adsorb most VOCs; samples are later desorbed with carbon disulfide or by thermal desorption and analyzed by GC-MS or GC-FID.
The OSHA permissible exposure limit (PEL) for respirable crystalline silica is 50 µg/m³ as an 8-hr TWA, established under which standard?
Answer: 29 CFR 1910.1053 (General Industry Silica Standard)
OSHA finalized the Respirable Crystalline Silica standard (29 CFR 1910.1053) in 2016, setting the PEL at 50 µg/m³ — half the previous limit — to reduce silicosis risk.
When multiple chemicals are present in the workplace, OSHA requires that additive effects be considered. How is the combined exposure evaluated?
Answer: Sum each exposure fraction (C₁/L₁ + C₂/L₂ + … Cₙ/Lₙ); if sum >1, the PEL is exceeded
Per 29 CFR 1910.1000(d)(2), when chemicals have similar health effects, their fractional exposures are summed; a combined ratio exceeding 1 indicates a PEL exceedance.
What is the primary purpose of a Hearing Conservation Program baseline audiogram?
Answer: To establish a reference hearing level against which future tests are compared to detect hearing loss
The baseline audiogram establishes each worker's initial hearing threshold, enabling comparison with annual audiograms to detect standard threshold shifts (STS) early.
Which type of ventilation system captures contaminants at their source before they can disperse into the general workroom air?
Answer: Local exhaust ventilation (LEV)
Local exhaust ventilation captures contaminants at the point of generation using hoods, ductwork, and a fan-filter system, providing more effective control than dilution ventilation.