Certification Practice Exam Questions

Certified Industrial Hygienist (CIH) Certification Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

1. The primary goal of industrial hygiene is to:

• Promote employee benefits
• Anticipate, recognize, evaluate, and control workplace hazards
• Enforce company policy
• Develop marketing plans

Rationale: The purpose of industrial hygiene is to protect worker health by

identifying and controlling environmental factors that may cause illness or discomfort.

• Which of the following is an example of a chemical hazard?
• Noise 1 / 4

• Solvents
• Heat stress
• Radiation

Rationale: Solvents are chemical substances that can cause toxic effects

through inhalation, ingestion, or skin contact.

3. The permissible exposure limit (PEL) is established by:

A. OSHA

B. NIOSH

C. ACGIH

D. EPA

Rationale: OSHA establishes and enforces PELs to regulate worker

exposure to hazardous substances.

• Which organization publishes Threshold Limit Values (TLVs)?

A. OSHA

B. ACGIH

C. NIOSH

D. ANSI

Rationale: The American Conference of Governmental Industrial Hygienists

(ACGIH) publishes TLVs as recommended exposure limits.

• / 4

5. The primary route of exposure for airborne contaminants is:

• Ingestion
• Inhalation
• Injection
• Absorption

Rationale: Inhalation is the main route of exposure for airborne

contaminants such as dust, vapors, and gases.

• Which of the following instruments is used to measure airborne

particulates?

• Gas chromatograph
• Aerosol photometer
• Noise dosimeter
• Spectrophotometer

Rationale: Aerosol photometers are used to measure the concentration of

airborne particles in workplace air.

7. The unit used to express noise levels is:

• Lux
• Pascal
• Decibel (dB)
• Hertz (Hz) 3 / 4

Rationale: Noise intensity is expressed in decibels, a logarithmic unit that

measures sound pressure level.

8. The most common occupational illness in industry is:

• Asthma
• Hearing loss
• Dermatitis
• Silicosis

Rationale: Occupational hearing loss is one of the most prevalent and

preventable occupational diseases.

• Which sampling device is most appropriate for collecting gases and

vapors?

• Filter cassette
• Charcoal tube
• Cyclone sampler
• Impactor

Rationale: Charcoal tubes are used for active sampling of gases and

vapors, capturing them for later analysis.

10. Time-Weighted Average (TWA) exposure refers to:

• Instantaneous exposure at any moment
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