Certified Industrial Hygienists 2026 (CIH) are experts who protect people from harmful chemicals and other hazards in workplaces and other settings. The CIH certification is awarded by the Board for Global EHS Credentialing and requires college education, work experience, rigorous examination and ongoing professional development.
A CIH can help identify and control hazardous materials, including asbestos, lead-based paint, mold and radon in older buildings. This can protect workers and residents of a building from illnesses ranging from asthma to cancer and Sick Building Syndrome.
Prepare for the CIH - Certified Industrial Hygienist Exam exam with our free practice test modules. Each quiz covers key topics to help you pass on your first try.
CIH certifications show employers and clients that you’ve met high standards of education, knowledge and experience. They also indicate that you’re committed to continuing professional development. Those who are certified are generally in demand by employers and can command higher salaries than those without the designation.
Applicants must hold at least a bachelor’s degree in industrial hygiene, engineering (biology, chemical, mechanical or sanitary), science, or a related field and have 4 years of professional-level, broad-scope industrial hygiene experience. They must also pass a written exam, which contains 100 multiple-choice questions. The CIH exam is administered by Prometric at locations nationwide. Its passing score is based on statistical equating, which helps to ensure that candidates are evaluated on the same competency standard.
In addition to discussing the CIH exam, panelists discussed other issues facing the profession. McCluskey says that the economic crisis has led to consolidation and a rise in consultants, which could impact how industrial hygienists work with small businesses and other companies. He believes this trend may result in a change in how the exam is designed and that it should reflect these changes.
Industrial hygienists are experts in the field of workplace health and safety. Their job is to assess potential hazards and determine ways to minimize them. This requires a high level of education, training, and work experience. In addition, industrial hygienists must have excellent communication skills and the ability to think critically.
The qualifications for a certified industrial hygienist include a bachelor’s degree in industrial hygiene or occupational health and safety, as well as professional field experience. In addition, they must pass the CIH exam, which is administered by the American Board of Industrial Hygiene. The exam is challenging and can take up to five years to complete.
CIHs work in a variety of fields, including the military, government agencies, schools, and hospitals. Their duties include assessing risk factors in the environment, such as toxic substances, air quality, noise, and vibrations. They also help ensure that companies comply with governmental regulations and laws. They may also be responsible for implementing and maintaining hazard control programs. They work closely with upper management to implement a holistic risk management system.
An industrial hygienist is a specialist who can identify and address potential health and safety risks in the workplace, surrounding environment, or public area. These risks can be physical, chemical, biological, or environmental. An industrial hygienist can also provide guidance on how to reduce or manage a worker’s exposure to hazardous situations and substances.
• Earn a bachelor’s degree in engineering, chemistry, physics, or biology, or in industrial hygiene.
• Complete an internship in occupational health and safety.
• Employ for entry-level positions.
• A master’s degree may be an option.
• Get certified as an industrial hygienist.
Industrial hygienists study, identify, and quantify occupational risks or pressures that could expose employees to chemicals, physical exertion, ergonomic hazards, or biological stresses that could result in illness, deteriorated health, or substantial discomfort.
As of June 26, 2026, the average industrial hygienist pay in the United States was $94,015; however, the normal income range is between $80,649 and $111,599.
“Anticipate health and safety risks and devise methods to prevent them,” is the job role of an industrial hygienist.
Industrial hygienists frequently work in fields with a high prevalence of possible health risks. You could work as an industrial hygienist in a setting that involves manufacturing, chemical processing, building, or research.
Try these questions from our free CIH - Certified Industrial Hygienist Exam practice tests. The correct answer and an explanation follow each question.
An industrial hygienist needs to evaluate worker exposure to a mixture of organic solvents with synergistic health effects. Which sampling strategy is most appropriate?
Answer: B. Use separate sorbent tubes optimized for each component and sum the fractions of their respective OELs
For synergistic mixtures, ACGIH and OSHA require that the sum of fractions (C1/TLV1 + C2/TLV2…) must not exceed 1.0, necessitating quantification of each component.
An industrial hygienist completes an exposure assessment for lead and finds that while all 8-hour TWA results are below the OSHA PEL, several are above the Action Level. What is the most appropriate next step regarding risk communication?
Answer: A. Notify the affected employees in writing of their individual results within the mandated timeframe.
The OSHA Lead Standard (29 CFR 1910.1025) explicitly requires employers to notify each employee in writing of their exposure monitoring results within a specific timeframe (e.g., 15 working days) after receiving them. This requirement applies regardless of whether the PEL is exceeded, and it is crucial when exposures meet or exceed the Action Level, as this triggers other requirements like medical surveillance.
Under OSHA's general industry standard for powered industrial trucks (29 CFR 1910.178), operators must be evaluated and re-certified at minimum every:
Answer: C. 3 years
Forklift operators must be re-evaluated at least every three years, or sooner if observed operating unsafely.
An industrial hygienist is evaluating an LEV system where workers are still being overexposed to a chemical vapor despite the system running. The capture velocity at the source is adequate, but there are visible dust deposits in the horizontal duct runs. What is the most likely cause of this issue?
Answer: C. The transport velocity in the duct is too low.
The presence of settled material in the ductwork is a classic sign of insufficient transport velocity. The airflow must be fast enough to keep the contaminant entrained in the airstream and prevent it from settling out due to gravity. Even with good capture velocity, low transport velocity will cause the system to fail.
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| Pros | Cons |
|---|---|
| CIH certification validates expertise recognized by employers nationwide | Must complete continuing education to maintain active certification |
| Opens doors to advanced positions and leadership roles | Pass rates vary — thorough preparation is essential for success |
| Demonstrates commitment to professional standards and ethics | Some certifications require prerequisite experience or education |