AIEHS Certified Industrial Hygiene CIHP Exam
**Question 1.** Which year is recognized as the founding of modern industrial hygiene when
Dr. Alice Hamilton began her work at the Harvard School of Public Health?
A) 1907
B) 1912
C) 1918
D) 1925
Answer: A
Explanation: Dr. Alice Hamilton’s appointment in 1907 is widely regarded as the start of
organized industrial hygiene in the United States.
**Question 2.** The primary responsibility of an industrial hygienist is to:
A) Conduct employee performance reviews
B) Identify, evaluate, and control workplace environmental hazards
C) Design manufacturing equipment
D) Manage payroll and benefits
Answer: B
Explanation: Industrial hygienists focus on protecting worker health by managing chemical,
physical, and biological hazards.
**Question 3.** In the Occupational Health and Safety (OHS) management cycle, which step
follows “Hazard Identification”?
A) Control Implementation
B) Planning
C) Evaluation of Controls
D) Hazard Communication
Answer: A
, AIEHS Certified Industrial Hygiene CIHP Exam
Explanation: After hazards are identified, the next logical step is to select and implement control
measures.
**Question 4.** Which organ system is most directly affected by inhalation of airborne silica
particles?
A) Cardiovascular system
B) Respiratory system
C) Nervous system
D) Musculoskeletal system
Answer: B
Explanation: Inhaled silica deposits in the lungs, causing silicosis and other respiratory diseases.
**Question 5.** The dose‑response relationship that shows a threshold below which no
adverse effect is observed is called:
A) Linear no‑threshold (LNT)
B) Threshold model
C) Hormesis
D) Sigmoidal model
Answer: B
Explanation: A threshold model indicates that exposures below a certain dose produce no
measurable effect.
**Question 6.** LD50 is a toxicological term that refers to:
A) The dose that kills 50 % of a test population
B) The dose that causes 50 % of the maximum effect
C) The daily exposure limit for workers
D) The limit of detection for analytical methods
, AIEHS Certified Industrial Hygiene CIHP Exam
Answer: A
Explanation: LD50 (lethal dose, 50 %) is the amount of a substance that kills half the test
animals.
**Question 7.** Which route of entry is most likely for a solvent that readily evaporates at
room temperature?
A) Ingestion
B) Dermal absorption
C) Inhalation
D) Injection
Answer: C
Explanation: Volatile solvents are primarily absorbed through the respiratory tract when
inhaled.
**Question 8.** Convert a concentration of 2 ppm of a gas with a molecular weight of 44 g/mol
to mg/m³ at 25 °C and 1 atm. (Use 24.45 L/mol)
A) 1.8 mg/m³
B) 2.0 mg/m³
C) 3.6 mg/m³
D) 4.5 mg/m³
Answer: C
Explanation: mg/m³ = ppm × MW / 24.45 → 2 × .45 ≈ 3.6 mg/m³.
**Question 9.** A worker’s 8‑hour time‑weighted average (TWA) exposure to a chemical is
55 ppm. The OSHA PEL for that chemical is 50 ppm. The worker is in compliance because:
A) The TWA is below the PEL after a 10 % safety factor
B) The PEL is a ceiling limit, not a TWA
, AIEHS Certified Industrial Hygiene CIHP Exam
C) The worker exceeds the PEL and is non‑compliant
D) The PEL applies only to 10‑hour shifts
Answer: C
Explanation: The measured TWA (55 ppm) exceeds the OSHA permissible exposure limit
(50 ppm), indicating non‑compliance.
**Question 10.** Which of the following is NOT a typical component of a Safety Data Sheet
(SDS)?
A) Hazard identification
B) Physical and chemical properties
C) Employee performance evaluation
D) Exposure controls and personal protection
Answer: C
Explanation: SDSs contain hazard, handling, and control information; employee evaluations are
unrelated.
**Question 11.** In a walkthrough survey, the industrial hygienist should first:
A) Review the plant’s financial statements
B) Observe work processes and note visible hazards
C) Conduct blood sampling on workers
D) Install permanent monitoring equipment
Answer: B
Explanation: Direct observation of operations helps identify visible and potential hazards early
in the survey.
**Question 12.** Which type of dust is most commonly associated with the development of
pneumoconiosis in coal miners?
**Question 1.** Which year is recognized as the founding of modern industrial hygiene when
Dr. Alice Hamilton began her work at the Harvard School of Public Health?
A) 1907
B) 1912
C) 1918
D) 1925
Answer: A
Explanation: Dr. Alice Hamilton’s appointment in 1907 is widely regarded as the start of
organized industrial hygiene in the United States.
**Question 2.** The primary responsibility of an industrial hygienist is to:
A) Conduct employee performance reviews
B) Identify, evaluate, and control workplace environmental hazards
C) Design manufacturing equipment
D) Manage payroll and benefits
Answer: B
Explanation: Industrial hygienists focus on protecting worker health by managing chemical,
physical, and biological hazards.
**Question 3.** In the Occupational Health and Safety (OHS) management cycle, which step
follows “Hazard Identification”?
A) Control Implementation
B) Planning
C) Evaluation of Controls
D) Hazard Communication
Answer: A
, AIEHS Certified Industrial Hygiene CIHP Exam
Explanation: After hazards are identified, the next logical step is to select and implement control
measures.
**Question 4.** Which organ system is most directly affected by inhalation of airborne silica
particles?
A) Cardiovascular system
B) Respiratory system
C) Nervous system
D) Musculoskeletal system
Answer: B
Explanation: Inhaled silica deposits in the lungs, causing silicosis and other respiratory diseases.
**Question 5.** The dose‑response relationship that shows a threshold below which no
adverse effect is observed is called:
A) Linear no‑threshold (LNT)
B) Threshold model
C) Hormesis
D) Sigmoidal model
Answer: B
Explanation: A threshold model indicates that exposures below a certain dose produce no
measurable effect.
**Question 6.** LD50 is a toxicological term that refers to:
A) The dose that kills 50 % of a test population
B) The dose that causes 50 % of the maximum effect
C) The daily exposure limit for workers
D) The limit of detection for analytical methods
, AIEHS Certified Industrial Hygiene CIHP Exam
Answer: A
Explanation: LD50 (lethal dose, 50 %) is the amount of a substance that kills half the test
animals.
**Question 7.** Which route of entry is most likely for a solvent that readily evaporates at
room temperature?
A) Ingestion
B) Dermal absorption
C) Inhalation
D) Injection
Answer: C
Explanation: Volatile solvents are primarily absorbed through the respiratory tract when
inhaled.
**Question 8.** Convert a concentration of 2 ppm of a gas with a molecular weight of 44 g/mol
to mg/m³ at 25 °C and 1 atm. (Use 24.45 L/mol)
A) 1.8 mg/m³
B) 2.0 mg/m³
C) 3.6 mg/m³
D) 4.5 mg/m³
Answer: C
Explanation: mg/m³ = ppm × MW / 24.45 → 2 × .45 ≈ 3.6 mg/m³.
**Question 9.** A worker’s 8‑hour time‑weighted average (TWA) exposure to a chemical is
55 ppm. The OSHA PEL for that chemical is 50 ppm. The worker is in compliance because:
A) The TWA is below the PEL after a 10 % safety factor
B) The PEL is a ceiling limit, not a TWA
, AIEHS Certified Industrial Hygiene CIHP Exam
C) The worker exceeds the PEL and is non‑compliant
D) The PEL applies only to 10‑hour shifts
Answer: C
Explanation: The measured TWA (55 ppm) exceeds the OSHA permissible exposure limit
(50 ppm), indicating non‑compliance.
**Question 10.** Which of the following is NOT a typical component of a Safety Data Sheet
(SDS)?
A) Hazard identification
B) Physical and chemical properties
C) Employee performance evaluation
D) Exposure controls and personal protection
Answer: C
Explanation: SDSs contain hazard, handling, and control information; employee evaluations are
unrelated.
**Question 11.** In a walkthrough survey, the industrial hygienist should first:
A) Review the plant’s financial statements
B) Observe work processes and note visible hazards
C) Conduct blood sampling on workers
D) Install permanent monitoring equipment
Answer: B
Explanation: Direct observation of operations helps identify visible and potential hazards early
in the survey.
**Question 12.** Which type of dust is most commonly associated with the development of
pneumoconiosis in coal miners?
