COHN COHN Environmental and Industrial Hygiene 1 — Questions and Answers
Question 1: What does the hierarchy of controls prioritize as the most effective method for controlling workplace hazards?
- Administrative controls
- Personal protective equipment (PPE)
- Engineering controls
- Elimination of the hazard (Correct answer)
Correct answer: Elimination of the hazard
Elimination removes the hazard entirely and is the most effective control at the top of the hierarchy, followed by substitution, engineering controls, administrative controls, and PPE.
Question 2: Which industrial hygiene principle involves replacing a hazardous substance with a less hazardous one?
- Engineering control
- Administrative control
- Substitution (Correct answer)
- Isolation
Correct answer: Substitution
Substitution is a preventive control that reduces risk by replacing a harmful material or process with a safer alternative.
Question 3: What is the Permissible Exposure Limit (PEL) as defined by OSHA?
- The maximum concentration of a substance allowed in outdoor air
- The legal limit for worker exposure to a chemical or physical agent in the workplace (Correct answer)
- The recommended exposure level set by NIOSH for emergency response
- The dose of a substance that causes death in 50% of test animals
Correct answer: The legal limit for worker exposure to a chemical or physical agent in the workplace
PELs are legally enforceable limits set by OSHA that define the maximum amount of a hazardous substance a worker may be exposed to over a specified time period.
Question 4: Which agency publishes Threshold Limit Values (TLVs) for workplace chemical exposures?
- OSHA
- NIOSH
- ACGIH (American Conference of Governmental Industrial Hygienists) (Correct answer)
- EPA
Correct answer: ACGIH (American Conference of Governmental Industrial Hygienists)
ACGIH publishes TLVs as guidelines representing conditions under which nearly all workers may be repeatedly exposed without adverse health effects.
Question 5: In industrial hygiene, what does 'air sampling' primarily assess?
- Temperature and humidity levels in the workplace
- Noise levels exceeding OSHA action levels
- Concentration of airborne contaminants in the breathing zone (Correct answer)
- Radiation exposure of workers in nuclear facilities
Correct answer: Concentration of airborne contaminants in the breathing zone
Air sampling quantifies airborne chemical or biological contaminants in workers' breathing zones to compare against PELs, TLVs, or RELs.
Question 6: What type of ventilation system removes contaminants at their source before they can spread into the work area?
- General dilution ventilation
- Local exhaust ventilation (LEV) (Correct answer)
- Positive pressure ventilation
- Recirculation ventilation
Correct answer: Local exhaust ventilation (LEV)
Local exhaust ventilation captures and removes airborne contaminants at or near their point of generation, preventing worker exposure.
COHN COHN Environmental and Industrial Hygiene 1
What does the hierarchy of controls prioritize as the most effective method for controlling workplace hazards?