- Which CRER This Is, and Why the Acronym Matters
- Who Issues and Administers the Credential
- The Five Skill Groups the Issuer Names
- What the Exam Looks Like
- Eligibility and the Application Route
- Fees, Retakes, and Renewal Obligations
- The Reference Library Behind the Exam
- Reading the Published Pass Ratio Carefully
- Certification Versus a State License
- How CRER Sits Beside CRMR and CIER
- Sequencing Your Preparation
- Frequently Asked Questions
- CRER here means Council-certified Residential Environmental Remediator, issued through the American Council for Accredited Certification (ACAC).
- The exam is 50 multiple-choice questions in two hours, closed book, with a 70% passing criterion.
- Initial US/Canada cost is USD 400; retakes are USD 100; the credential runs two years.
- Five skill groups drive preparation: asbestos, lead, hazardous materials, microbial contaminants and allergens, and chemicals.
Which CRER This Is, and Why the Acronym Matters
Several unrelated credentials share the letters CRER, and search results blend them together. This article is about one specific credential: the Council-certified Residential Environmental Remediator. It is an individual certification in indoor environmental remediation, administered by ACAC. Fee schedules, exam formats, and renewal rules from any other credential that happens to abbreviate to CRER do not apply here, so if you land on a page quoting figures you cannot trace to ACAC, treat it with suspicion.
If you want the short-form definitions, our companion pages on what CRER stands for and CRER meaning cover the naming question. This page goes further: what the certification actually requires, what it tests, and how to approach it.
Who Issues and Administers the Credential
ACAC, the American Council for Accredited Certification, is the issuing body. Certification decisions are made by its CRER Certification Board, not by the testing vendor. The exam itself is delivered through Kryterion, Inc., which handles the testing-center and online proctored delivery. That split matters in practice: Kryterion administers the sitting, but eligibility, scoring policy, and the final certification decision belong to the board.
The passing criterion of 70% was set by the certification board using a modified Angoff method, a standard-setting technique in which subject-matter experts judge how a minimally competent candidate would perform on each item. In plain terms, the cut score reflects a judgment about minimum competence rather than a curve against other test takers. See our breakdown of the CRER passing score for more.
The Five Skill Groups the Issuer Names
ACAC's handbook lists the competencies a CRER candidate must demonstrate under "The Required Skills." Each is phrased as understanding and executing successful remediation in the indoor environment, which signals that the exam leans toward applied, procedure-level knowledge rather than pure definitions. The handbook publishes no percentage weights, so treat these as unweighted preparation headings, not an official blueprint with exam-share numbers. Our complete guide to the five CRER content areas goes deeper on each.
Domain 1: Understand and execute successful remediation of asbestos in the indoor environment
Asbestos work is heavily regulated, so expect questions that tie technique to regulatory text.
- Engineering controls such as containment, negative air, and wetting methods
- Removal and cleaning procedures, and how waste is handled
- Worker protection requirements, including respiratory protection
- Source reading: 40 CFR 763, 40 CFR 61 Subpart M, and 29 CFR 1926.1101
Domain 2: Understand and execute successful remediation of lead in the indoor environment
Lead questions typically connect work practices to exposure control for both workers and occupants.
- Containment and dust control during disturbance of lead-containing surfaces
- Cleaning verification concepts and post-work cleanup
- Worker protection obligations under the construction lead standard
- Source reading: 40 CFR 745 and 29 CFR 1926.62
Domain 3: Understand and execute successful remediation of hazardous materials in the indoor environment
This group is the broadest in subject matter. It is where the handbook's mercury and methamphetamine-laboratory references live.
- Spill and release response for elemental mercury
- Cleanup principles for former clandestine drug-lab sites
- Hazardous waste operations and worker safety framework
- Source reading: 29 CFR 1910.120, the mercury guidebook sections, and EPA's methamphetamine laboratory cleanup guidelines
Domain 4: Understand and execute successful remediation of microbial contaminants and allergens in the indoor environment
This is the group most people associate with residential remediation work.
- Moisture source correction as a precondition for any cleanup
- Containment, air filtration, and removal or cleaning of affected materials
- Worker protection, including respirator selection logic
- Source reading: the NYC fungi-remediation guidance (2008) and NIOSH Respirator Selection Logic (2004)
Domain 5: Understand and execute successful remediation of chemicals in the indoor environment
Chemical questions test your ability to recognize hazards and match controls to them.
- Ventilation and source-removal controls for chemical contaminants
- Cleaning, neutralization, and disposal considerations
- Personal protective equipment and respiratory selection
- Applicable regulatory references drawn from the handbook's reference list
What the Exam Looks Like
The CRER examination consists of 50 multiple-choice questions with at least four answer choices each. You get two hours, and the exam is closed book. Question and answer order are randomized, and results are immediate. Delivery options include testing centers and online video-proctored sessions. The current application form also mentions instructor-proctored vocational examinations arranged through ACAC.
One wrinkle: ACAC's generic examinations page states a range of 75 to 120 questions across its programs. The exact CRER handbook specifies 50, and that is the number to plan around. For a realistic sense of difficulty, read how hard the CRER exam is.
| Exam Feature | CRER Detail |
|---|---|
| Questions | 50 multiple choice, at least four answer choices |
| Time limit | Two hours |
| Materials | Closed book |
| Passing criterion | 70%, set by the certification board (modified Angoff) |
| Delivery | Testing center or online video-proctored; vocational proctoring via ACAC arrangements |
| Results | Immediate; randomized question and answer order |
Online testing requirements
Candidates testing online must supply their own computer, an approved webcam, a private location, and a continuous 2 Mbps upload and download connection. Test your setup well before the exam day rather than discovering a bandwidth problem mid-session. If the home environment is unreliable, a testing center removes that variable entirely. Scheduling details are in our guide to CRER exam dates.
Eligibility and the Application Route
CRER eligibility is built around current work in the field. The handbook requires current employment in indoor environmental remediation, while the current application form's affidavit names indoor environmental consulting and adds attestations covering legal work status, regulatory compliance, and ethics. Those two descriptions are not word-for-word identical, so read the live application carefully and confirm any ambiguity with ACAC before you pay anything.
Two things CRER does not impose: it does not require the two-year experience route that applies to the CIER credential, and it does not require a degree. The application involves an electronic signature, required email verification, the examination, and a unanimous review by the certification board.
For a fuller walk-through, see our CRER requirements guide. One caution: some career-information sites list this credential with added education or experience prerequisites. Those listings conflict with the issuer's employment-attestation route, so rely on ACAC.
Fees, Retakes, and Renewal Obligations
The initial fee for US and Canada candidates is USD 400, made up of USD 100 for the examination and USD 300 for vocational certification covering the first two-year term. The current official application quotes USD 425 for candidates outside the US and Canada. A retake costs USD 100. A prep course is optional, so any course or study material you buy is a separate decision and separate expense from the issuer's charges.
| Cost Item | Amount | Notes |
|---|---|---|
| Initial certification (US/Canada) | USD 400 | USD 100 exam plus USD 300 vocational certification, first two-year term |
| Initial certification (outside US/Canada) | USD 425 | Per current official application |
| Retake | USD 100 | Examination only |
| Renewal | USD 300 | Plus required recertification credits |
| Prep materials | Varies | Optional; not an issuer charge |
Staying certified
The credential is valid for two years. Renewal costs USD 300 and requires 40 recertification credits (RCs). Current procedures allocate 10 of those for continued field activity and require 30 professional-development hours. Keep your documentation, because records can be audited. A detailed cost discussion is in our CRER certification cost breakdown, and whether the investment pays off is covered in is the CRER certification worth it.
The Reference Library Behind the Exam
Because the exam is closed book and assumes comprehensive familiarity with ACAC's references, your preparation is largely a reading project. Treat each source as study material and ask three questions of every section: what engineering controls does it prescribe, how is cleaning or removal carried out, and what protects the worker?
- Asbestos: 40 CFR 763, 40 CFR 61 Subpart M, and 29 CFR 1926.1101
- Lead: 40 CFR 745 and 29 CFR 1926.62
- Hazardous materials: 29 CFR 1910.120, EPA mercury guidance, and EPA methamphetamine laboratory cleanup guidelines
- Microbial contaminants and allergens: NYC fungi-remediation guidance (2008)
- Worker protection across groups: NIOSH Respirator Selection Logic (2004)
- Professional conduct: ACAC ethics provisions
For a concise recap once you have done the reading, a CRER cheat sheet helps consolidate the facts, and our CRER study guide lays out a full preparation approach.
Reading the Published Pass Ratio Carefully
ACAC's 2025 exam pass ratio for CRER is listed as 0%, based on 0 passes out of 2 examinations. That is a denominator of two. A cohort that small cannot tell you how difficult the exam typically is, and the report also includes retakes and state-licensing-only examinations, which muddies what the figure represents. Do not read it as evidence that the exam is nearly impossible, and do not read it as a prediction for your own attempt. Our CRER pass rate analysis explains how to interpret figures like this responsibly.
Certification Versus a State License
CRER certification is awarded to individuals. Passing an examination that is solely for licensing does not authorize you to use the CRER designation, and holding CRER does not replace jurisdiction-specific licensing requirements. If you work in a state or locality that licenses mold, asbestos, or lead professionals, you must satisfy those requirements separately through the relevant official agency. Check your own jurisdiction's regulator rather than assuming the certification covers you.
How CRER Sits Beside CRMR and CIER
People searching for CRER often also encounter CRMR and CIER. Without importing any outside details, the key CRER-specific distinctions are these: CRER is an employment-attested route with no degree prerequisite, and it does not impose the two-year experience route associated with CIER. Consumer-facing hiring guides sometimes compare remediator credentials, but those are advice for homeowners, not authority on exam scope, licensing, or ACAC ethics. For role-oriented context, see CRER jobs, and for earnings, the CRER salary guide, which distinguishes occupational wages from any unverified certification premium.
Sequencing Your Preparation
Because no weights are published, divide your time by familiarity and regulatory density rather than by assumed exam share. Regulation-heavy groups reward early, slow reading; groups closer to your daily work may need less. A sensible ordering follows.
Asbestos and lead
- Read the 40 CFR and 29 CFR provisions line by line
- Note engineering controls, cleanup methods, and worker protections for each
Hazardous materials
- Study both mercury guidebook titles and sections as ACAC lists them
- Cover methamphetamine laboratory cleanup and 29 CFR 1910.120
Microbial contaminants and chemicals
- Work through the NYC fungi guidance
- Pair every control with NIOSH respirator selection logic
Timed practice
- Sit full 50-question, two-hour practice sessions on the CRER practice test
- Review every miss against its source document
Key Takeaway
Use practice questions to find gaps, then return to the primary source. Because the exam is closed book and the references are broad, memorizing answer patterns is a weaker strategy than understanding why a control or procedure applies. Practice at CRER Exam Prep is most useful when paired with the reading list above.
Frequently Asked Questions
Here it stands for Council-certified Residential Environmental Remediator, an individual certification in indoor environmental remediation issued through the American Council for Accredited Certification (ACAC). Other credentials share the acronym, so confirm you are looking at ACAC's version.
The exam has 50 multiple-choice questions, a two-hour limit, and a 70% passing criterion set by the certification board. It is closed book, and results are immediate.
The initial US/Canada fee is USD 400, split between a USD 100 examination fee and a USD 300 vocational certification fee for the first two-year term. Outside the US and Canada the current application quotes USD 425, and a retake is USD 100. Study materials are optional extra expenses.
No degree prerequisite applies, and the current application page expressly exempts CRER from project sheets. Eligibility centers on current work in indoor environmental remediation, with attestations on legal work status, compliance, and ethics.
It is valid for two years. Renewal costs USD 300 and requires 40 recertification credits, with 10 for continued field activity and 30 professional-development hours. Keep documentation in case of audit.