COSS Industrial Hygiene 1 — Questions and Answers
Question 1: Which of the following best defines industrial hygiene?
- The practice of maintaining cleanliness in manufacturing facilities
- The science of anticipating, recognizing, evaluating, and controlling workplace health hazards (Correct answer)
- The process of inspecting facilities for OSHA compliance violations
- The administration of first aid and medical treatment in occupational settings
Correct answer: The science of anticipating, recognizing, evaluating, and controlling workplace health hazards
Industrial hygiene is defined as the science and art of anticipating, recognizing, evaluating, and controlling environmental factors arising from or in the workplace that may cause sickness or impaired health.
Question 2: The ACGIH Threshold Limit Value (TLV-TWA) represents the airborne concentration of a substance to which workers may be repeatedly exposed for how long without adverse health effects?
- 8 hours per day, 40 hours per week (Correct answer)
- 4 hours per day, 20 hours per week
- 12 hours per day, 60 hours per week
- 10 hours per day, 50 hours per week
Correct answer: 8 hours per day, 40 hours per week
The TLV-TWA is the time-weighted average concentration for a conventional 8-hour workday and 40-hour workweek that nearly all workers may be repeatedly exposed to without adverse effects.
Question 3: Which industrial hygiene sampling method collects a contaminant sample over a defined period to determine the average concentration during that time?
- Grab sampling
- Composite sampling
- Integrated sampling (Correct answer)
- Instantaneous sampling
Correct answer: Integrated sampling
Integrated (or long-term) sampling collects the contaminant over a defined period, typically a full work shift, to determine the time-weighted average concentration.
Question 4: What does the term 'action level' (AL) represent under OSHA health standards?
- The concentration requiring immediate evacuation of all workers
- The concentration at which OSHA requires immediate medical treatment
- Half the permissible exposure limit that triggers certain compliance requirements (Correct answer)
- The ceiling concentration that must never be exceeded
Correct answer: Half the permissible exposure limit that triggers certain compliance requirements
OSHA's action level is typically set at 50% of the PEL and triggers requirements such as air monitoring, medical surveillance, and employee training.
Question 5: Which category of health hazard is associated with noise-induced hearing loss?
- Chemical hazard
- Biological hazard
- Physical hazard (Correct answer)
- Ergonomic hazard
Correct answer: Physical hazard
Noise is classified as a physical hazard because it involves energy (sound waves) rather than chemical or biological agents that affect the body.
Question 6: An industrial hygienist is evaluating a worker's exposure to multiple chemical solvents simultaneously. What concept should be applied when the substances have additive effects?
- Synergistic effect calculation
- The mixture formula using the sum of fractions rule (Correct answer)
- The highest individual TLV for the mixture
- A 50% reduction in the individual TLVs
Correct answer: The mixture formula using the sum of fractions rule
When substances have additive effects, ACGIH recommends applying the mixture formula where the sum of each substance's concentration divided by its respective TLV must not exceed 1.
Question 7: Which control method is considered most effective in the industrial hygiene hierarchy of controls?
- Administrative controls
- Personal protective equipment
- Engineering controls
- Elimination or substitution (Correct answer)
Correct answer: Elimination or substitution
Elimination or substitution of the hazard is at the top of the hierarchy of controls because it completely removes the hazard rather than managing worker exposure to it.
COSS Industrial Hygiene 1
Which of the following best defines industrial hygiene?