Industrial Hygiene Flashcards

The dose-response relationship in toxicology demonstrates which fundamental principle?

Answer: The greater the dose, the greater the biological response

The dose-response relationship is a foundational toxicological principle showing that as the dose of a substance increases, the magnitude of the biological response also increases.

Under OSHA's Occupational Noise Exposure standard (29 CFR 1910.95), a Hearing Conservation Program must be implemented when employee TWA noise exposures reach or exceed which level?

Answer: 85 dBA

OSHA requires a Hearing Conservation Program when employees are exposed to an 8-hour TWA of 85 dBA or greater (the action level), even though the PEL is 90 dBA.

What industrial hygiene term describes the concentration of a chemical at which 50% of a test animal population dies in a specified time period during inhalation exposure?

Answer: LC50

LC50 (Lethal Concentration 50%) is the inhalation concentration that kills 50% of the test population; LD50 applies to ingested or absorbed doses rather than inhaled concentrations.

Which industrial hygiene term refers to the minimum concentration of a flammable vapor in air below which ignition cannot occur?

Answer: Lower explosive limit (LEL)

The Lower Explosive Limit (LEL) is the minimum vapor concentration at which a flammable mixture can ignite; below this concentration the mixture is 'too lean' to burn.

When evaluating heat stress in workers, which index accounts for temperature, humidity, radiant heat, and air movement?

Answer: Wet Bulb Globe Temperature (WBGT)

The Wet Bulb Globe Temperature (WBGT) is the primary index used in occupational settings to assess heat stress because it incorporates air temperature, humidity, radiant heat, and air movement.

Which type of respirator provides the highest level of respiratory protection by supplying breathable air from an independent source?

Answer: Self-contained breathing apparatus (SCBA)

A Self-Contained Breathing Apparatus (SCBA) carries its own air supply and is assigned the highest protection factors, making it the standard for IDLH atmospheres and emergency response.

Industrial hygiene qualitative exposure assessments are MOST useful during which phase of the hazard management process?

Answer: During initial hazard recognition to prioritize which operations need quantitative monitoring

Qualitative exposure assessment is most valuable in the recognition phase to prioritize worker groups and operations that pose the highest risk, guiding where quantitative air sampling resources should be focused.