- The One-Page Snapshot
- Exam Format at a Glance
- Fees, Application Timeline and Logistics
- Eligibility Rules to Memorize
- The Five Competency Areas
- Regulation and Reference Quick List
- What the Public Record Does Not Tell You
- Renewal and Recertification Credits
- Who Uses the Credential and How It Differs From CMR
- A Domain-Ordered Review Sequence
- Frequently Asked Questions
- The CIER exam has 100 multiple-choice questions, three hours, closed book, with a 75% passing score.
- Initial cost is $500: $100 exam plus $400 certification, including a $100 nonrefundable processing fee.
- Eligibility requires four project sheets and experience in at least two of five areas: asbestos, lead, hazardous materials, microbial/allergens...
- Certification lasts two years; current procedures require 40 recertification credits (10 field activity, 30 professional development).
The One-Page Snapshot
This cheat sheet condenses the facts about the Council-certified Indoor Environmental Remediator credential into a format you can review in minutes. The credential is issued by the American Council for Accredited Certification (ACAC) through its CIER Certification Board, and the program is accredited by the Council for Engineering and Scientific Specialty Boards (CESB). Exam delivery runs through Kryterion, Inc.
Everything below comes from ACAC's published handbook, fee pages and procedures as rechecked in October 2026. Where ACAC's own pages disagree with each other, this article says so rather than picking a winner. If you want the longer narrative version of any topic, the CIER study guide walks through a full first-attempt plan.
| Item | Must-Know Fact |
|---|---|
| Certifying body | ACAC, CIER Certification Board |
| Accreditation | CESB |
| Questions | 100 multiple-choice, at least four answer options each |
| Time | Three hours, computer-delivered, closed book |
| Passing score | 75%, set by the Modified Angoff method |
| Practical component | None described |
| Validity | Two years |
Exam Format at a Glance
What the questions look like
Expect straightforward multiple-choice items with at least four options. The handbook describes a fixed question set with randomized question and answer order, so two candidates see the same pool in different sequences. Adaptive testing is not described. The split between scored and unscored questions is not published, so treat every item as if it counts.
Why 75% matters
The 75% cut score comes from the Modified Angoff method, in which subject-matter experts judge how a minimally competent remediator would perform on each item. On 100 questions, that translates to 75 correct answers if all items are scored. Because the scored count is unpublished, do not build your plan around a razor-thin margin. For more on the mechanics, see what you need to pass the CIER exam.
Delivery options
- Testing center: Bring two government-issued IDs, including one photo ID.
- Online proctoring: Requires your own computer, an approved webcam and a private location. ACAC specifies at least 2 Mbps upload and download speed and excludes phones and tablets.
- Results: Scores are available electronically immediately and confirmed by email.
- Arrival time: ACAC's Examinations page says arrive 15 minutes early; the handbook says 30. Plan for 30 and you satisfy both.
- Calculator policy: Unverified. Confirm with ACAC before exam day rather than assuming.
Fees, Application Timeline and Logistics
All amounts are in USD and come from ACAC's Fees and Payments page.
| Charge | Amount | Note |
|---|---|---|
| Examination | $100 | Paid for the exam itself |
| Certification | $400 | Includes a $100 nonrefundable processing fee |
| Initial total | $500 | Covers the first two-year term |
| Retake | $100 | Per additional attempt |
| Renewal | $400 | For each renewal term |
No separate member and non-member fee schedule is published. For the full budgeting picture, including what the fee does not cover, read the CIER certification cost breakdown.
The application clock
ACAC's current application page specifies online submission with required email verifications, and says you have six months to finish the entire process, including the exam. Approval requires a unanimous board vote, and the page says the board meets every four to six weeks. That cadence affects how you schedule everything, so check CIER exam dates and scheduling before committing to a target month.
Eligibility Rules to Memorize
There are two qualifying routes, and both require documented, hands-on indoor environmental remediation experience.
- Education route: a related two-year postsecondary degree, or 15 qualifying college credits, plus at least one year of documented indoor environmental remediation experience.
- Experience route: a high school diploma or GED plus two years of documented experience.
The breadth requirement
Your experience must cover at least two of these five areas: asbestos; lead; hazardous materials; microbial/allergens; and IH/chemicals/toxicology. Single-discipline experience does not satisfy the rule, so a candidate who has only ever run mold jobs needs documented work in a second area.
Project sheets and verification
You must submit four project sheets, plus applicable educational evidence and experience verification. ACAC's FAQ requires actual field experience and describes each sheet in three parts: the problem, your own responsibilities and actions, and the outcome. The emphasis on your own actions matters. A sheet that describes what the crew or the company did, without clarifying your role, is a weak submission.
No mandatory preparation course or minimum training-hour requirement is published, and ACAC does not develop or administer prep courses. The full eligibility walkthrough lives in CIER requirements and how to qualify.
The Five Competency Areas
ACAC's handbook publishes five competency headings. They are unweighted preparation topics. No public formal exam-domain chart or percentage weighting was verified, so you cannot responsibly claim one area is "worth the most." Each competency addresses engineering controls, cleaning and removal methods, worker safety and applicable regulations, which gives you a four-lens template for every domain.
Domain 1: Understand and execute successful remediation of asbestos in the indoor environment
Anchor this area in the asbestos regulations listed in the study materials.
- 40 CFR 763 and 40 CFR 61 Subpart M
- 29 CFR 1926.1101 for worker protection in construction
- Containment, negative-pressure engineering controls and removal methods
Domain 2: Understand and execute successful remediation of lead in the indoor environment
Pair the lead rules with practical work-practice knowledge.
- 40 CFR 745 for lead-based paint requirements
- 29 CFR 1926.62 for lead exposure in construction
- Dust control, cleaning methods and worker exposure protection
Domain 3: Understand and execute successful remediation of hazardous materials in the indoor environment
This is the broadest heading, and it connects to emergency-response and site-safety rules.
- 29 CFR 1910.120 (hazardous waste operations and emergency response)
- Mercury-response material, whose citation differs across ACAC documents (see below)
- EPA Voluntary Guidelines for Methamphetamine Laboratory Cleanup
Domain 4: Understand and execute successful remediation of microbial contaminants and allergens in the indoor environment
Mold and allergen work is where many candidates feel most at home, but the exam still rewards reference-specific knowledge.
- New York City Department of Health and Mental Hygiene, Guidelines on Assessment and Remediation of Fungi in Indoor Environments (2008)
- Containment, source removal and moisture-control logic
- Respiratory protection selection for microbial work
Domain 5: Understand and execute successful remediation of chemicals in the indoor environment
This heading maps most closely to the IH/chemicals/toxicology experience category.
- Chemical hazard recognition and exposure control
- NIOSH Respirator Selection Logic (2004)
- Cleaning and removal methods matched to the contaminant
For a deeper treatment of how each heading plays out, see the complete guide to all five CIER content areas. Candidates wondering about workload can also read how hard the CIER exam really is.
Regulation and Reference Quick List
ACAC's study guide lists the following materials. Memorize which topic each one belongs to, because matching a citation to its subject is a fast way to eliminate wrong answers.
| Reference | Subject Area |
|---|---|
| ACAC Code of Conduct | Professional ethics |
| 40 CFR 763 | Asbestos |
| 40 CFR 61 Subpart M | Asbestos (emission standard) |
| 29 CFR 1926.1101 | Asbestos (construction worker protection) |
| 40 CFR 745 | Lead |
| 29 CFR 1926.62 | Lead (construction worker protection) |
| 29 CFR 1910.120 | Hazardous waste operations and emergency response |
| NYC DOHMH Fungi Guidelines (2008) | Microbial remediation |
| NIOSH Respirator Selection Logic (2004) | Respiratory protection |
| EPA Voluntary Guidelines for Methamphetamine Laboratory Cleanup | Clandestine lab cleanup |
| Mercury-response material | Mercury spills and cleanup |
Two cautions apply. First, reference-publication dates are not exam-version dates; the 2004 and 2008 dates above tell you when documents were issued, not which exam edition you will see. Second, ACAC warns that the study guide's selected pages are examples, not exhaustive coverage, and advises comprehensive study of the references.
What the Public Record Does Not Tell You
A good cheat sheet is honest about its gaps. These items are not publicly established:
- Domain weights: The handbook says the board prescribes an exam blueprint, but no domain chart or percentages are reproduced publicly.
- Exam version: The public handbook page is undated, and no separately identified 2026 exam version was verified.
- Scored versus unscored items: Not published.
- Pass rate: No numerical CIER pass rate is publicly disclosed.
Reading the pass-rate evidence correctly
ACAC's Accredited Certification Activity report as of December 31, 2025 shows dashes for applicants, pass ratio and recertifications, with 0 current certifications. CIER is also absent from the 2025 Exam Pass Ratio report. A dash is not a 0% pass rate, and a zero current-certificant count does not prove the credential is discontinued. It simply means the issuer reports no usable number. Treat anyone quoting a precise CIER pass percentage with suspicion. The CIER pass rate analysis explains how to interpret these reports.
Key Takeaway
When a site gives you a confident CIER pass rate or domain percentage, ask for the source. Neither figure is in ACAC's public materials, so any specific number is unverified.
Renewal and Recertification Credits
The certification is valid for two years. ACAC's current Recertification Procedures specify 40 recertification credits (RCs) per term:
- 10 RCs for continued field activity
- 30 RCs for professional development during the term
You must attest to your credits and retain evidence in case of audit, and a current photo is requested. Renewal costs $400.
Who Uses the Credential and How It Differs From CMR
The credential suits professionals whose work spans indoor contaminants: remediation contractors, project managers and supervisors, and consultants who oversee abatement or cleanup. The two-of-five experience rule signals that the board expects multi-discipline competence rather than a single-trade specialty.
No reliable salary survey specific to ACAC CIER holders was verified, and no causal earnings premium has been established, so this article cites no figures. For a sober look at value, see the CIER salary analysis and the ROI discussion on whether CIER is worth it.
CIER versus ACAC's CMR
ACAC also offers a mold-focused credential, the Council-certified Microbial Remediator (CMR), described on its Mold Remediation page. The practical difference is scope: CMR centers on microbial work, while CIER spans asbestos, lead, hazardous materials, microbial/allergens and chemicals. If your career is mold-only, the narrower credential may fit better. If you work across contaminant types, the five-domain scope of CIER matches your daily reality. Review the program details on ACAC's own pages before deciding, since this article does not cover CMR's eligibility or exam specifics.
A Domain-Ordered Review Sequence
Because no weighting is published, schedule by your own gaps rather than by guesswork. A reasonable approach is to spend the most time where your field experience is thinnest, since the exam covers all five areas while your job probably does not.
Asbestos and lead rules
- Pair 40 CFR 763 and 40 CFR 61 Subpart M with 29 CFR 1926.1101
- Pair 40 CFR 745 with 29 CFR 1926.62
- For each, list the engineering controls, removal method and worker protections
Hazardous materials and chemicals
- Work through 29 CFR 1910.120 and the mercury and methamphetamine cleanup material
- Practice respirator selection with the NIOSH logic
Microbial contaminants and allergens
- Study the NYC fungi guidelines for assessment and remediation logic
- Connect containment and source removal to worker safety
Timed mixed practice
- Simulate the three-hour, 100-question format
- Review every miss against the specific regulation behind it
Reserve your experience gaps for extra time. If you came up through mold work, give asbestos and lead extra days; if you come from abatement, do the reverse. When you are ready to test yourself under realistic conditions, the CIER practice test is a good place to find your weak domains, and the main practice site lets you repeat questions until the citations stick.
Frequently Asked Questions
The exam has 100 multiple-choice questions with at least four answer options each, delivered by computer over three hours with no reference materials. The passing score is 75%, set using the Modified Angoff method. ACAC does not publish how many questions are scored versus unscored.
The initial total is $500 in USD: a $100 examination fee plus a $400 certification fee that includes a $100 nonrefundable processing fee. That covers the first two-year term. A retake costs $100 and renewal costs $400.
Not necessarily. You can qualify with a related two-year postsecondary degree or 15 qualifying college credits plus one year of documented experience, or with a high school diploma or GED plus two years. Either way, your experience must cover at least two of the five listed areas and you must submit four project sheets.
No numerical pass rate is publicly disclosed. ACAC's 2025 activity report shows dashes rather than figures, and CIER does not appear in the 2025 Exam Pass Ratio report. A dash is not a 0% pass rate, so be wary of any specific percentage you encounter.
Renew every two years with 40 recertification credits under ACAC's current procedures: 10 for continued field activity and 30 for professional development. You attest to the credits and retain evidence for possible audit, and renewal costs $400. Because ACAC's pages word the requirement differently in places, confirm the current procedures page before you start collecting credits.
For broader background on the credential itself, you can also explore what CIER certification is, and revisit this CIER cheat sheet as exam day approaches.