COSS Industrial Hygiene 3

Question 1

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

Accepted Answer

The greater the dose, the greater the biological response

Answer

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.

Question 2

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?

Accepted Answer

85 dBA

Answer

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.

Question 3

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?

Accepted Answer

LC50

Answer

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.

Question 4

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

Accepted Answer

Lower explosive limit (LEL)

Answer

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.

Question 5

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

Accepted Answer

Wet Bulb Globe Temperature (WBGT)

Answer

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.

COSS - Certified Occupational Safety Specialist Practice Test

COSS - Certified Occupational Safety Specialist Practice Test

COSS Industrial Hygiene 3