CERTIFIED INDUSTRIAL HYGIENIST (CIH)
CERTIFICATION QUESTION AND
CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. The primary goal of industrial hygiene is to:
A. Increase production efficiency
B. Reduce operating costs
C. Protect worker health and well-being
D. Ensure regulatory compliance only
Answer: C
Rationale: Industrial hygiene focuses on anticipating, recognizing, evaluating,
and controlling workplace hazards to protect workers’ health.
2. Which discipline is most closely associated with exposure assessment?
A. Epidemiology
B. Toxicology
C. Industrial hygiene
D. Ergonomics
Answer: C
Rationale: Exposure assessment is a core function of industrial hygiene practice.
3. The hierarchy of controls ranks which method as most effective?
A. Personal protective equipment
B. Administrative controls
, C. Engineering controls
D. Elimination
Answer: D
Rationale: Eliminating the hazard entirely provides the highest level of
protection.
4. Threshold Limit Values (TLVs) are developed by:
A. OSHA
B. NIOSH
C. ACGIH
D. EPA
Answer: C
Rationale: TLVs are occupational exposure guidelines published by ACGIH.
5. OSHA Permissible Exposure Limits (PELs) are:
A. Advisory only
B. Legally enforceable
C. Recommended guidelines
D. Industry standards
Answer: B
Rationale: OSHA PELs are regulatory limits enforceable by law.
6. Which sampling method measures airborne contaminants over a work
shift?
A. Grab sampling
B. Area sampling
C. Personal sampling
D. Bulk sampling
Answer: C
Rationale: Personal sampling measures an individual worker’s exposure during
the shift.
, 7. The most common unit for airborne contaminant concentration is:
A. mg/L
B. mg/m³
C. g/cm³
D. ppm/hr
Answer: B
Rationale: mg/m³ is standard for mass concentration of airborne contaminants.
8. Which gas detector principle is used for combustible gases?
A. Photoionization
B. Infrared absorption
C. Catalytic combustion
D. Colorimetric reaction
Answer: C
Rationale: Catalytic bead sensors detect combustible gases by oxidation.
9. Noise-induced hearing loss primarily affects which frequency range?
A. Low frequencies
B. High frequencies
C. Mid frequencies
D. All frequencies equally
Answer: B
Rationale: High-frequency hearing is typically damaged first by noise exposure.
10.The OSHA action level for noise exposure is:
A. 80 dBA
B. 85 dBA
C. 90 dBA
D. 95 dBA
Answer: B
Rationale: OSHA requires hearing conservation programs at 85 dBA TWA.
CERTIFICATION QUESTION AND
CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. The primary goal of industrial hygiene is to:
A. Increase production efficiency
B. Reduce operating costs
C. Protect worker health and well-being
D. Ensure regulatory compliance only
Answer: C
Rationale: Industrial hygiene focuses on anticipating, recognizing, evaluating,
and controlling workplace hazards to protect workers’ health.
2. Which discipline is most closely associated with exposure assessment?
A. Epidemiology
B. Toxicology
C. Industrial hygiene
D. Ergonomics
Answer: C
Rationale: Exposure assessment is a core function of industrial hygiene practice.
3. The hierarchy of controls ranks which method as most effective?
A. Personal protective equipment
B. Administrative controls
, C. Engineering controls
D. Elimination
Answer: D
Rationale: Eliminating the hazard entirely provides the highest level of
protection.
4. Threshold Limit Values (TLVs) are developed by:
A. OSHA
B. NIOSH
C. ACGIH
D. EPA
Answer: C
Rationale: TLVs are occupational exposure guidelines published by ACGIH.
5. OSHA Permissible Exposure Limits (PELs) are:
A. Advisory only
B. Legally enforceable
C. Recommended guidelines
D. Industry standards
Answer: B
Rationale: OSHA PELs are regulatory limits enforceable by law.
6. Which sampling method measures airborne contaminants over a work
shift?
A. Grab sampling
B. Area sampling
C. Personal sampling
D. Bulk sampling
Answer: C
Rationale: Personal sampling measures an individual worker’s exposure during
the shift.
, 7. The most common unit for airborne contaminant concentration is:
A. mg/L
B. mg/m³
C. g/cm³
D. ppm/hr
Answer: B
Rationale: mg/m³ is standard for mass concentration of airborne contaminants.
8. Which gas detector principle is used for combustible gases?
A. Photoionization
B. Infrared absorption
C. Catalytic combustion
D. Colorimetric reaction
Answer: C
Rationale: Catalytic bead sensors detect combustible gases by oxidation.
9. Noise-induced hearing loss primarily affects which frequency range?
A. Low frequencies
B. High frequencies
C. Mid frequencies
D. All frequencies equally
Answer: B
Rationale: High-frequency hearing is typically damaged first by noise exposure.
10.The OSHA action level for noise exposure is:
A. 80 dBA
B. 85 dBA
C. 90 dBA
D. 95 dBA
Answer: B
Rationale: OSHA requires hearing conservation programs at 85 dBA TWA.
