CIH: Certified Industrial Hygienist Exam Practice Test

Candidates must hold a bachelor's degree from an accredited institution and have professional experience in industrial hygiene. The specific years of experience required depend on the level of education: a bachelor's degree requires 4 years of experience; a master's degree requires 3 years; and a doctoral degree requires 2 years. Experience must be verified by references and must demonstrate progressive responsibility in the anticipation, recognition, evaluation, and control of environmental health hazards.

The CIH exam is a computer-based test consisting of 200 multiple-choice questions, of which 180 are scored. Candidates are given 8 hours to complete the exam, which is typically administered in two 4-hour sessions. The questions are scenario-based and integrative, requiring the application of knowledge from across the CIH core competencies. The exam is closed-book, and a reference sheet with relevant formulas is provided.

While both are premier credentials, the CIH focuses specifically on the science of occupational health-anticipating, recognizing, evaluating, and controlling health hazards (chemical, biological, physical, ergonomic). The Certified Safety Professional (CSP) certification has a broader focus on safety hazard prevention, including topics like fire protection, system safety, and equipment guarding. Many professionals hold both certifications (CIH/CSP) to demonstrate comprehensive EHS expertise. The CIH is deeply rooted in toxicology, epidemiology, and engineering controls for health risks.

CIHs must maintain their certification through a robust recertification process every five years. This requires earning a minimum of 40 continuing education contact hours (CM points) specific to industrial hygiene and/or the CIH core competencies. Additionally, holders must adhere to the BGC Code of Ethics and pay biennial certification maintenance fees. This ensures CIHs remain current with evolving science, technology, and regulations in the field.

The exam is based on a detailed blueprint covering eight core domains: 1) Air Sampling & Instrumentation, 2) Analytical Chemistry, 3) Basic Science, 4) Biohazards, 5) Biostatistics & Epidemiology, 6) Community Exposure, 7) Engineering Controls/Ventilation, 8) Ergonomics, 9) Health Risk Analysis & Hazard Communication, 10) IH Program Management, 11) Noise, 12) Non-Engineering Controls, 13) Radiation, 14) Thermal Stressors, and 15) Toxicology. Questions integrate knowledge across these domains.