- The Short Answer: What CIEC Stands For
- Who Issues the Credential
- Why the Acronym Causes Confusion
- What Each Word in the Title Signals
- The Exam Behind the Name
- The Seven Examination Domains
- Earning the Title: Eligibility and Application
- Fees, Term and Renewal
- Where the Credential Fits in Practice
- The Handbook Reading List
- A Domain-Ordered Study Sequence
- Frequently Asked Questions
- CIEC stands for Council-certified Indoor Environmental Consultant, a credential issued by the American Council for Accredited Certification (ACAC).
- The exam is 120 multiple-choice questions in 3 hours, closed-book, with a 75% passing score.
- The official scope covers seven domains, including Respiratory Protection, which the handbook's shorter six-heading list omits.
- Qualifying requires documented IAQ investigation experience, four project sheets, and unanimous board approval, not just a passing score.
The Short Answer: What CIEC Stands For
CIEC stands for Council-certified Indoor Environmental Consultant. It is a professional credential for people who investigate, assess and advise on indoor air quality and related indoor environmental problems in buildings. The "Council" in the name refers to the American Council for Accredited Certification, the body that sets the standards, administers the examination and grants the designation.
If you have landed here from a search, you may have seen the same four letters attached to other credentials in unrelated fields. This article is about one thing only: the indoor environmental consulting designation awarded through ACAC. For a broader orientation, see our overview pages on what CIEC is and what CIEC certification involves.
Who Issues the Credential
The American Council for Accredited Certification (ACAC) issues the CIEC. ACAC publishes the candidate handbook, maintains the examination domain chart, sets the fee schedule, reviews applications, and decides on certification. The written examination itself is delivered through the testing provider Kryterion, either at a testing center or through online video proctoring, with electronic scores available immediately after the exam.
That division of labor matters for how you think about the name. The credential is not granted by a training company, a software vendor or an employer. It is granted by a certifying council after a review of your education, your documented project experience and your exam performance. The word "Council-certified" is the part of the title that tells an employer or client that an independent board, not a course provider, vouched for you.
Why the Acronym Causes Confusion
"CIEC" is a short acronym, and several unrelated credentials and organizations use the same letters. That is the main reason people search for what it stands for. A few practical ways to make sure you are looking at the right one:
- Check the issuer. The credential discussed on this site is issued by ACAC. If a page describes a different certifying body, it is describing a different credential, and its fees, dates and exam details will not apply here.
- Check the subject matter. The CIEC in this article concerns indoor air quality, building science, HVAC, microbial and chemical contaminants, remediation and respiratory protection.
- Check the full name. If a source never spells out "Council-certified Indoor Environmental Consultant," treat its numbers with caution.
What Each Word in the Title Signals
Council-certified
The designation is conferred by ACAC, not self-declared. Certification requires unanimous board approval, which means a passing exam score alone does not earn the title. Notably, passing the examination for state licensing purposes alone does not confer the CIEC designation.
Indoor Environmental
The scope is the built indoor environment: air quality, moisture and mold, chemical exposures, ventilation and building performance. The seven examination domains reflect this breadth, running from contaminants and health effects through building science and HVAC to remediation and respirator use.
Consultant
The role is investigative and advisory. Eligibility rests on documented IAQ investigations, not classroom hours, and the application asks for project sheets that show you have actually worked cases. That is why the experience requirement spans several technical areas rather than a single specialty.
The Exam Behind the Name
The written examination is a closed-book test of 120 multiple-choice questions, each with at least four answer choices, with a 3-hour time limit. The passing score is 75%, set using the modified Angoff method, a standard-setting approach in which subject-matter experts judge how a minimally qualified candidate would perform on each item. If you want the scoring details, see our page on the CIEC passing score.
| Exam Feature | Detail |
|---|---|
| Format | Multiple choice, at least four options per question |
| Number of questions | 120 |
| Time allowed | 3 hours |
| Reference materials | Closed-book |
| Passing score | 75% (modified Angoff method) |
| Delivery | Kryterion: testing center or online video proctoring |
| Score reporting | Electronic scores available immediately |
| ID at testing centers | Two government-issued IDs, including one photo ID |
Because the exam is closed-book, you cannot rely on looking up exposure limits, air-exchange concepts or respirator selection logic during the test. You need working recall. For a realistic picture of the challenge, read how hard the CIEC exam is, and for outcome data, see what the pass-rate data shows.
The Seven Examination Domains
The official scope comes from ACAC's CIEC and CIE Examinations chart, approved February 7, 2024. The chart lists seven domains. ACAC does not publish percentage weights in the complete chart, so this article does not assign any. One detail worth knowing: the candidate handbook's abbreviated list shows only six headings and leaves out Respiratory Protection, while the complete chart includes it. Plan your preparation around all seven. Our complete guide to the CIEC exam domains goes deeper on each area.
Domain 1: IAQ Contaminants and Potential Health Effects
The foundation of the credential: what is in indoor air and how it can affect occupants.
- Microbial contaminants such as mold and related moisture-driven problems
- Chemical contaminants and basic toxicology concepts
- Linking symptoms and exposures to likely sources
Domain 2: Principles of Building Science & the Built Environment
How buildings behave as systems, and why problems originate where they do.
- Moisture movement and building envelope performance
- How construction and use patterns influence indoor conditions
Domain 3: HVAC
Ventilation and air-handling knowledge, central to most IAQ investigations.
- How HVAC operation affects air quality and comfort
- Ventilation concepts drawn from guidance such as EPA's building air quality materials
Domain 4: Equipment Selection, Calibration and Operation
Choosing and using the right instruments and keeping measurements defensible.
- Matching sampling and measurement tools to the question being asked
- Calibration and proper operation as a basis for credible data
Domain 5: Guidelines, Regulations and Standards
The rulebook that frames what you assess and recommend.
- Knowing which guidance applies to which situation
- Distinguishing enforceable requirements from voluntary guidelines
Domain 6: Remediation
What to do once a problem is identified and characterized.
- Containment, cleanup and verification principles
- Mold-focused remediation concepts from the handbook's reference list
Domain 7: Respiratory Protection
Protecting workers and consultants during investigations and remediation.
- Respirator selection logic
- Program requirements under the OSHA respiratory protection standard
Earning the Title: Eligibility and Application
The CIEC is an experience-based credential. ACAC accepts three education-and-experience pathways, each paired with documented IAQ investigations:
- A qualifying science-related four-year degree (or a 30-credit equivalent) plus four years of documented IAQ investigations.
- A qualifying two-year degree (or a 15-credit equivalent) plus six years.
- A high-school diploma or GED plus eight years.
Across any pathway, your experience must span at least three of five areas: Lead/Asbestos, Microbial, IH/Chemicals/Toxicology, Building Sciences, and IAQ/HVAC. You submit four project sheets, applicable education transcripts and required email verifications. Certification then requires unanimous board approval. No training course is mandatory. For the full picture, see our guide to CIEC requirements and how to qualify.
Fees, Term and Renewal
| Item | Amount (USD) |
|---|---|
| Examination fee | $100 |
| Certification fee | $400 |
| First two-year term, US/Canada | $500 total |
| First two-year term, outside US/Canada | $525 |
| Retake | $100 |
| Renewal | $400 plus 40 recertification credits |
Certification is valid for two years. Renewal requires 40 recertification credits: 10 credits for attesting to continued field activity plus 30 hours of professional development. Keep documentation in case of an audit. The CIEC certification cost breakdown walks through how these figures fit together over time.
Where the Credential Fits in Practice
Because the title says "consultant," the typical setting is advisory work: investigating complaints about air quality, assessing moisture and mold conditions, evaluating ventilation, and recommending corrective action. The credential is most relevant to people who already work in or alongside indoor environmental, industrial hygiene, building diagnostics or remediation roles, and who want an independent council-backed designation to demonstrate their competence to clients and employers.
Compensation varies widely with region, employer type and experience, and this article does not cite specific figures. If you are weighing the investment, our pages on CIEC jobs, the CIEC salary guide and whether the certification is worth it discuss the career side in more depth.
The Handbook Reading List
The candidate handbook prescribes a set of preparation references. These are best treated as the core of your reading, since they map directly to the domains above:
- AIHA, Recognition, Evaluation & Control of Indoor Mold, second edition (2020)
- EPA, Building Air Quality: A Guide for Building Owners and Facility Managers (1991)
- Managing Indoor Air Quality, fourth or fifth edition (2008/2011)
- NIOSH, Respirator Selection Logic (2004)
- OSHA, Small Entity Compliance Guide for the Respiratory Protection Standard (2011)
Notice how the list leans on microbial control, building and HVAC guidance, and respirator programs. That emphasis is a useful clue to the exam's center of gravity. Our CIEC study guide and one-page cheat sheet help you condense this material for review.
A Domain-Ordered Study Sequence
Since the exam is closed-book and spans seven domains, sequencing matters more than volume. One workable order builds from causes to controls:
Contaminants and Building Science
- Domain 1 and Domain 2 first, because every later topic depends on understanding sources and moisture behavior
HVAC and Instruments
- Domains 3 and 4 together: ventilation concepts and the tools used to measure them
Rules, Remediation, Respirators
- Domains 5, 6 and 7, including the respiratory protection material the handbook's short list leaves out
Finish with timed practice. The CIEC practice test lets you rehearse the 120-question, 3-hour pacing, and working through full question sets at our main practice site helps reveal which domains need another pass.
Frequently Asked Questions
CIEC stands for Council-certified Indoor Environmental Consultant, a credential issued by the American Council for Accredited Certification (ACAC).
No. Several unrelated credentials share these letters. The CIEC discussed here is the ACAC-issued indoor environmental consulting designation, so check the issuing body before relying on any fee, date or exam detail.
The exam has 120 multiple-choice questions, each with at least four choices, in a 3-hour closed-book session. The passing score is 75%.
No. You must also meet the education and documented-experience requirements, submit four project sheets, and receive unanimous board approval. Passing a state-licensing exam alone does not confer the designation.
Certification is valid for two years. Renewal costs $400 and requires 40 recertification credits: 10 for attesting to continued field activity and 30 hours of professional development.