CIH Exam Blueprint: 3 Domains, 9 Tasks Explained
BGC's official CIH Exam Blueprint, based on their 2021 Job Analysis (effective April 1, 2022): 3 performance domains, 9 tasks within them, a condensed view of the knowledge each task draws on, and the 17 technical subject areas exam questions are categorized under.
The CIH exam is 180 multiple-choice questions (150 scored + 30 pilot) over 5.0 hours, split into two 2.5-hour sections. It tests 3 domains: Exposure Assessment (50%), Control Selection & Validation (35%), and Risk Management (15%) — so half the exam, by weight, is exposure assessment alone.
CIH exam format at a glance
| Questions | 180 total (150 scored + 30 unscored pilot) |
| Time limit | 5.0 hours (two 2.5-hour sections, optional 30-min break) |
| Format | Multiple-choice, computer-based |
| Delivered by | Pearson VUE test centres |
| Exam fee | $370 USD, plus a separate $160 application fee (BGC fee schedule, checked September 21, 2026 — confirm before paying) |
| Exam windows | Twice yearly — April–May and October–November |
The 3 CIH exam domains
Each domain breaks down into tasks — specific activities a practicing CIH performs — and each task lists the knowledge areas BGC expects you to draw on to perform it. The knowledge lists below are a condensed overview of BGC's full blueprint, not a replacement for it: BGC also publishes a “skill in” list for every task (see the skills table below), and some knowledge items overlap between tasks because real IH work draws on the same core science repeatedly. Read the official blueprint for the complete text.
I. Exposure Assessment Principles and Practice
50%Half the exam by itself. Covers the full lifecycle of identifying a hazard, deciding whether it's actually a problem, measuring it properly, and drawing sound conclusions from the data.
II. Control Selection, Recommendation/Implementation, and Validation
35%Once a hazard is confirmed, this domain covers picking the right control, actually putting it in place, and proving it worked. This is where ventilation, noise abatement, radiation shielding, and PPE selection live.
III. Risk Management
15%The smallest domain, but a real one — it tests program-level thinking: building and maintaining an IH program, not just solving one exposure problem at a time.
Domain I alone (50%) carries as much weight as Domains II and III combined (35% + 15%), which makes it far heavier than the other two for anyone who splits study time evenly across "three domains." The exposure-assessment domain isn't just the biggest — it's the one every other domain assumes you've already mastered, since you can't select or validate a control for an exposure you never correctly assessed in the first place.
Domains and technical subjects work together
A domain describes a professional activity; a subject area describes the technical knowledge used to perform it. BGC categorizes examination questions by subject area, so plan study around both. A ventilation lesson, for example, should help you recognize an exposure problem, choose a control, check that it performs, and organize its upkeep. Build practice around decisions: what evidence is needed, which measurement fits, what the result means, what control is feasible, and how you will verify it.
BGC lists 17 subject areas in its official definitions (revised January 26, 2022). The table gives a one-line summary of each and links SPEP study pages where they exist. SPEP does not assign weights to individual subjects, and BGC does not publish them in these documents.
| Air sampling and instrumentation | Field air-sampling instruments, calibration, quality assurance, sampling strategy and related calculations. |
| Analytical chemistry | Laboratory methods for workplace samples, related calculations, laboratory quality assurance and chain of custody. |
| Basic science | Chemistry, biology, anatomy and physiology, physics, mathematics, gas-law and unit-conversion calculations, reactive-material compatibility. |
| Biohazards | Sanitation, hygiene, and the recognition, evaluation and control of infectious agents, molds, allergens, toxins, recombinant products and bloodborne pathogens. Study the biological hazards reference → |
| Biostatistics and epidemiology | Study designs, disease distribution, morbidity and mortality, basic biostatistics and interpreting data. |
| Community exposure | Air pollution and cleaning, ambient monitoring, dispersion, emergency planning, water pollution, hazardous waste, environmental fate. Community exposure reference → |
| Engineering controls / ventilation | Local exhaust and dilution ventilation, isolation, containment, airflow mechanics and measurement, design calculations. HVAC air cycle → |
| Ergonomics | Anthropometry, human factors, biomechanics and work physiology applied to workplace design. |
| Health risk analysis and hazard communication | Using TLVs, BEIs and other guidelines; the risk-reduction process, hierarchy of controls, control banding, hazard communication and training. |
| IH program management | Resources, auditing, investigation methods, data management, policy, accountability, risk communication and the BGC Code of Ethics. |
| Noise | Health effects of noise and vibration, combining sources, octave-band measurement, audiometric programs and control. Frequency weighting → |
| Non-engineering controls | Respirators and protective clothing (selection, fit testing, breathing air, glove permeability), eye protection and administrative controls. |
| Radiation: ionizing | Alpha, beta, gamma, neutron and x-radiation; source characteristics, measurement, evaluation and control. Radiation study page → |
| Radiation: nonionizing | Electromagnetic fields, lasers, radio frequency, microwaves, UV, visible and infrared radiation, illumination. |
| Thermal stressors | Health effects of heat and cold, symptoms, exposure control and first aid. |
| Toxicology | Effects of chemical agents and mixtures, pharmacokinetics, routes of entry, target organs, carcinogenic and reproductive hazards. Industrial toxicology reference → |
| Work environments and industrial processes | Hazards of processes such as confined space entry, spray painting, welding, abrasive blasting, degreasing, foundry work and hazardous waste remediation. |
Skills the condensed task lists leave out
Each task in BGC's blueprint has a “skill in” list as well as a knowledge list, and the cards above show only condensed knowledge. These are selected skills from the official blueprint that are easy to overlook. They are not a complete replacement for it. Verified against the official blueprint on September 21, 2026.
| Domain I, Task 1 | Hazards with no existing OEL; reconstructing exposures and forensic investigation; surveying tasks, materials, operations and sites. |
| Domain I, Task 2 | Toxicology concepts including latency; judging the credibility of an information source; hazards with no existing OEL. |
| Domain I, Task 3 | Identifying similar exposure groups; instrument operation and calibration; strengths and limitations of sampling and analytical methods; keeping field records; reviewing historical data and existing controls. |
| Domain I, Task 4 | Evaluating data quality; complex exposure scenarios; risks of previously unrecognized hazards; evaluating business impacts. |
| Domain II, Task 1 | Protective-clothing permeability and degradation; chemical incompatibility; individual differences between workers; evaluating the environment where a control will be used; interpreting building specifications. |
| Domain II, Task 2 | Reporting structures, roles and responsibilities; remediating hazards; applying ergonomic interventions; interpreting engineering instructions and specifications; developing policies. |
| Domain II, Task 3 | Air sampling of biological agents; microbiology; noise and vibration surveys; troubleshooting control technology; reading design drawings and specifications. |
| Domain III, Task 1 | Prioritizing program needs; integrating IH needs into business plans; identifying target audiences; applying ethical decision-making. |
| Domain III, Task 2 | Collecting and analyzing performance data; program and system management analysis; auditing programs and systems. |
Where a task list here mentions “biological hazards”, the biological hazards reference goes further than recognition: it ties each agent to its exposure route, the tasks where exposure occurs, and the controls to select and verify.
Studying the Domains This Blueprint Describes
The CIH Exam Journal follows real chapter-by-chapter prep against exactly these domains — toxicology, radiation, ventilation, noise, and more — plus the Equation Master for every calculation-heavy topic in Domain I and II.
Read the CIH Exam Journal →Or explore the full CIH Exam Prep Hub
CIH Exam Blueprint — Frequently asked questions
How many questions are on the CIH exam?
180 multiple-choice questions total: 150 scored questions plus 30 unscored pilot questions used to test future exam content. You won't know which questions are pilot questions while taking the exam.
How long is the CIH exam?
5.0 hours, split into two 2.5-hour sections with an optional 30-minute break in the middle. The second section begins after 30 minutes whether or not you've returned from break.
What are the three CIH exam domains?
Domain I: Exposure Assessment Principles and Practice (50% of the exam), Domain II: Control Selection, Recommendation/Implementation, and Validation (35%), and Domain III: Risk Management (15%). These come directly from BGC's published Job Analysis and Exam Blueprint.
Which CIH domain should I study most?
Domain I (Exposure Assessment) at 50% is half the exam by itself — recognizing hazards, assessing exposure-health relationships, designing assessment strategies, and drawing conclusions from data. Domain II (Controls) at 35% is the next largest. Domain III (Risk Management) is the smallest at 15%, covering program-level development and evaluation rather than technical exposure work.
How much does the CIH exam cost?
BGC lists a $370 USD examination fee, paid after your application is approved, plus a separate $160 application fee. Fees can change, so confirm on BGC's current fee schedule before paying (checked September 21, 2026). Exams are delivered through Pearson VUE test centres.
Does the domain weighting tell me how often each disease or technical subject appears?
No. Domain percentages describe how the exam is weighted across performance areas, not how often any single disease, subject or calculation appears. Use the published scope to guide coverage, and treat any personal study priority as a recommendation rather than a prediction.
Is this page a complete copy of BGC's requirements?
No. It is a condensed educational overview. The official exam blueprint and subject-area definitions give the full text. Every source SPEP cites is on the CIH references page.
Where should I check fees and exam arrangements?
On BGC's own site: the fee schedule for costs and the CIH applicant documents page for forms and requirements. Administrative details can change independently of the blueprint, so confirm them before you pay or book.
How should I use the biological hazards table for the exam?
Use it to practise connecting a workplace task with an exposure route and a control, then extend the exercise to how you would assess exposure and verify the control works. Memorizing organism names alone does not demonstrate those skills. See the biological hazards reference.
