What is a CIH and what does it take to qualify?
CIH stands for Certified Industrial Hygienist, the credential of the American Board of Industrial Hygiene, an independent accredited board that certifies practitioners of industrial hygiene — the discipline of anticipating, recognising, evaluating and controlling workplace conditions that can cause illness or impaired health, as distinct from injury-focused safety practice. Its eligibility is the strictest in the environment, health and safety field because it starts with academic content rather than with experience. Candidates need a bachelor's degree or higher with a specified quantity of science and mathematics coursework, including a defined amount of coursework in industrial hygiene and closely related subjects, and ABIH assesses transcripts against those requirements. On top of that, four years of professional-level industrial hygiene practice is required, in which the work involves genuine anticipation, recognition, evaluation and control of health hazards rather than administrative compliance support. Candidates then sit the ABIH examination covering the technical breadth of the discipline. Certification is maintained on a five-year cycle through certification maintenance points.
- CIH eligibility begins with an academic transcript review against specified science and industrial hygiene coursework.
- Four years of professional-level industrial hygiene practice is required on top of the academic gate.
- The examination spans exposure assessment, toxicology, ventilation, physical agents, statistics and regulation.
- It is a health-hazard specialism, distinct from the broad injury-prevention focus of safety certification.
CIH at a glance
| Cost | ABIH sets application, examination and certification maintenance fees separately and revises them, so pricing varies — see the current ABIH fee schedule |
| Duration | A single computer-based examination; the coursework and experience path spans years |
| Issued by | American Board of Industrial Hygiene (ABIH) |
| Format | Computer-based multiple-choice examination at approved test centres, following academic transcript and experience review |
| Expiry | Five-year certification maintenance cycle based on maintenance points |
| Who needs it | Industrial hygienists, EHS specialists and managers with occupational health responsibility, and consultants performing exposure assessment |
| Academic gate | A degree with specified science, mathematics and industrial hygiene coursework, assessed from transcripts |
| Experience | Four years of professional-level industrial hygiene practice |
Sources: American Board of Industrial Hygiene, official site · ABIH CIH certification requirements. Reviewed August 2026 by the GlobalCybers team.
The Academic Gate and the Examination
Eligibility is decided by your transcript
This is what makes the CIH different from every other EHS credential. Before experience is considered, ABIH assesses your academic transcripts against requirements for science and mathematics coursework and for coursework specifically in industrial hygiene and closely related subjects. Candidates from non-science degrees frequently have to take additional coursework before they are eligible at all — which is a multi-year detour, and the reason to check eligibility years before you intend to apply.
What the examination covers
Does the CIH change an EHS career?
It is the recognised technical credential for occupational health hazard evaluation and is named in consulting engagements, expert work and senior EHS roles with exposure responsibility, so it governs the technical work you can lead. BLS reports pay by occupation, not by credential.
GlobalCybers reimburses certification fees after a successful permanent placement through our network.
What the CIH Covers, Technical Domains
Exposure Assessment
Designing a sampling strategy that actually characterises exposure, rather than collecting samples that answer no question. The discipline's central skill.
Toxicology
Dose-response relationships, routes of exposure and target organ effects — the science that makes an exposure number meaningful.
Industrial Ventilation
Local exhaust design, capture velocity, hood selection and system evaluation. The most consequential engineering control in the field.
Physical Agents
Noise dosimetry, heat stress assessment, vibration and radiation — hazards measured with different instruments and different logic from chemical exposure.
Exposure Statistics
Variability, sample size and confidence in exposure judgements. Industrial hygiene decisions rest on small datasets, which makes the statistics unavoidable.
Respiratory Protection
Programme design, selection, fit testing and the limits of protection factors — an area where regulatory requirements and technical judgement intersect.
How do you become a Certified Industrial Hygienist, step by step?
Check your transcript against the academic requirement years early
ABIH assesses degrees against specified science and mathematics coursework and coursework in industrial hygiene and related subjects. If you are short, remedying it means taking courses — so discover the gap early rather than at application.
Get professional-level industrial hygiene experience
Four years of practice involving genuine anticipation, recognition, evaluation and control of health hazards is required. Administrative or compliance-support work generally does not satisfy the requirement.
Apply and pass the eligibility review
ABIH reviews transcripts and experience documentation before admitting a candidate to examination. Both parts are assessed, and the academic part is not negotiable through experience.
Prepare across the full technical breadth
The examination covers sampling and instrumentation, toxicology, ventilation, physical agents, biological agents, controls, statistics, regulation and communication. Practitioners specialised in one area routinely need substantial study elsewhere.
Sit the examination
The examination is computer-based at approved test centres. ABIH sets application and examination fees separately and revises them, so check the current fee schedule when applying.
Maintain on the five-year cycle
Certification is maintained through certification maintenance points earned over a five-year cycle from qualifying professional activity, recorded with ABIH.
Where the CIH Is Recognised
Industrial hygiene is not a licensed profession in most of the United States, so the credential is not a licence. Its recognition is nonetheless substantial: regulatory programmes and consensus standards reference industrial hygienists for defined evaluations, contracts and specifications require exposure assessments and ventilation evaluations to be performed by or under a certified industrial hygienist, litigation and expert work commonly demand it, and insurers and clients treat it as the technical qualification for health hazard determinations. In the absence of licensure, board certification is what establishes that competence.
CIH Certification, Frequently Asked Questions
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