- Which CRER This Is
- What a CRER Actually Does
- The Five Skill Groups You Must Master
- Exam Format and Delivery
- Who Can Apply
- Fees, Validity and Renewal
- Reading the Pass-Ratio Figure Carefully
- Source Reading Guide for the Study Phase
- CRER Compared With Related Credentials
- Sequencing Your Preparation
- Frequently Asked Questions
- CRER means Council-certified Residential Environmental Remediator, issued by the American Council for Accredited Certification (ACAC).
- The exam is 50 multiple-choice questions, two hours, closed book, with a 70% passing criterion.
- Initial US/Canada cost is USD 400; retakes are USD 100; certification lasts two years.
- Five issuer-supplied skill groups cover asbestos, lead, hazardous materials, microbial contaminants and allergens, and chemicals.
Which CRER This Is
The acronym CRER is shared by several unrelated credentials, so precision matters before you spend a dollar on preparation. On this site, a CRER is a Council-certified Residential Environmental Remediator: a person certified through the American Council for Accredited Certification (ACAC) to carry out remediation work in indoor environments. Certification decisions are made by ACAC's CRER Certification Board, and the examination is delivered through the testing provider Kryterion, Inc.
If you have seen "CRER" attached to other fields, those are different certifying bodies with different fees, dates and content. Nothing about them applies here. The rest of this article describes only the ACAC credential. If you want the shorter definitional versions of this topic, see What Is CRER?, What Does CRER Stand For? and CRER Meaning.
What a CRER Actually Does
A residential environmental remediator removes or controls contaminants inside buildings where people live and work. The practical work spans hazards that look very different on the job site but share a common logic: identify the contaminant, isolate it with engineering controls, clean or remove it, protect the workers doing so, and stay inside the applicable regulations.
That four-part logic is worth memorizing, because it recurs in every skill group on the exam. Whether the material is asbestos-containing material, lead-based paint dust, a spilled hazardous substance, mold growth or a chemical release, questions tend to probe the same four ideas: engineering controls, cleaning and removal methods, worker protection, and regulatory references.
The people who hold this credential typically work for remediation contractors, indoor environmental consulting firms and similar employers. For a closer look at the job side, see CRER Jobs. For earnings context, the CRER salary guide separates occupational wage data from any unverified certification premium, which is an important distinction: wage figures describe the occupation, not what the credential itself adds.
The Five Skill Groups You Must Master
ACAC's candidate handbook lists a set of Required Skills for the CRER, and these are tied to both the examination and board review. Five sequential headings are supplied, and they are used here as unweighted preparation headings. ACAC does not publish percentage weights, and the five headings should not be treated as an official numbered blueprint with proportions. Plan to study all five. For a longer treatment, read the complete guide to the five CRER content areas.
Domain 1: Understand and execute successful remediation of asbestos in the indoor environment
Expect questions on how asbestos-containing material is controlled, removed and handled during indoor work.
- Engineering controls such as containment and negative air during disturbance
- Removal and cleaning methods, including waste handling
- Worker protection requirements, including respiratory protection
- Regulatory references: 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 center on controlling dust and debris and protecting those who disturb lead-containing surfaces.
- Containment and dust-control approaches during disturbance
- Cleaning methods suited to fine lead dust
- Worker exposure protections and respirator selection
- Regulatory references: 40 CFR 745 and 29 CFR 1926.62
Domain 3: Understand and execute successful remediation of hazardous materials in the indoor environment
This is the broadest group and rewards candidates who can reason across substance types rather than memorize one procedure.
- Mercury response and cleanup, including the two differently titled guidebook references noted below
- Methamphetamine laboratory cleanup guidance from EPA
- Hazardous-waste operations and worker protection under 29 CFR 1910.120
- Respirator selection using the NIOSH Respirator Selection Logic
Domain 4: Understand and execute successful remediation of microbial contaminants and allergens in the indoor environment
Questions here concern fungal growth and related biological contaminants in occupied buildings.
- Moisture control and source correction as part of remediation
- Containment, removal and cleaning of contaminated materials
- Protection of workers and building occupants during the work
- Guidance reference: the NYC fungi-remediation guidance (2008)
Domain 5: Understand and execute successful remediation of chemicals in the indoor environment
Chemical questions test how you control exposure, ventilate, clean up and select protection for chemical contaminants.
- Ventilation and other engineering controls
- Cleanup and removal approaches by chemical type
- Respiratory and skin protection decisions
- Regulatory and hazard-communication awareness drawn from the handbook's references
One caution from the handbook itself: the study pages it points to are examples, and the exam assumes comprehensive knowledge of the referenced materials. Treat the listed pages as a starting point, not a boundary.
Exam Format and Delivery
The CRER handbook specifies a 50-question, multiple-choice, closed-book exam with a two-hour time limit. Each question offers at least four answer choices, and question and answer order is randomized. Results are immediate. The passing criterion is 70%, set by the certification board using a modified Angoff method. If you want the scoring details, see the CRER passing score guide.
You can test at a testing center or online with video proctoring. The current form also offers instructor-proctored vocational examinations through ACAC arrangements. Online candidates need their own computer, an approved webcam, a private location and a continuous 2 Mbps upload and download connection. Test your setup well before exam day, because a weak connection is an avoidable way to lose a session.
Optional preparation courses exist, but any course hours are separate from the exam's two-hour limit. Do not confuse course length with exam timing. For scheduling mechanics, see CRER exam dates and scheduling.
Who Can Apply
Eligibility is one of the areas where ACAC's own documents do not line up perfectly, so read carefully. The CRER handbook requires current employment in indoor environmental remediation. The current application form's affidavit instead names indoor environmental consulting and also requires legal work status plus regulatory-compliance and ethics attestations.
The process includes an application, an electronic signature, required email verification, the examination, and unanimous certification-board review. Notably, the current application page expressly exempts CRER from project sheets, even though generic handbook wording about the application process still mentions them. The CRER route does not impose the two-year experience route associated with the CIER credential, and no degree prerequisite applies.
| Topic | CRER handbook / current form | What to do |
|---|---|---|
| Employment basis | Handbook: current employment in indoor environmental remediation. Form affidavit: names indoor environmental consulting. | Confirm your employment fits the issuer's current wording before applying |
| Project sheets | Generic handbook language mentions them; the current application page exempts CRER | Follow the explicit CRER exemption |
| Time window | Current page permits six months; handbook retains generic 90-day language | Verify the current window on the official application |
| Verification | Current page uses online and email verification; handbook retains notarization and employer-affidavit language | Use the current application's process |
| Degree | No degree prerequisite for CRER | No diploma or transcript route is needed to qualify |
Third-party career profiles sometimes list education or experience requirements for this credential. Where those conflict with the issuer's employment-attestation route, the issuer governs. A fuller walkthrough is in CRER requirements and how to qualify.
Fees, Validity and Renewal
Keep three kinds of spending separate: charges paid to the issuer, optional preparation purchases, and recertification obligations.
| Item | Amount / rule |
|---|---|
| Initial fee, US/Canada | USD 400 total: USD 100 examination plus USD 300 vocational certification for the first two-year term |
| Current application quote outside US/Canada | USD 425 |
| Retake | USD 100 |
| Validity | Two years |
| Renewal | USD 300 and 40 recertification credits |
| Preparation course | Optional; priced separately from issuer fees |
Under current procedures, the 40 renewal credits break down as 10 for continued field activity and 30 professional-development hours. Keep documentation, since credits can be audited. The full pricing picture, including what is mandatory and what is optional, is in the CRER certification cost breakdown, and the ROI analysis helps you weigh it against your goals.
Reading the Pass-Ratio Figure Carefully
ACAC's 2025 exam pass ratio for CRER shows 0% (0 passes out of 2 examinations). It is tempting to read that as proof the exam is brutally hard. It is not. A denominator of two cannot establish typical difficulty. The report also includes retakes and state-licensing-only examinations, so even those two attempts do not map cleanly onto first-time certification candidates.
Key Takeaway
Treat the 2025 figure as a data point about a very small, mixed cohort, not as a prediction of your result. Judge difficulty by the content you must master and the 70% criterion, then build preparation accordingly. More context is in the pass-rate analysis and the difficulty guide.
Source Reading Guide for the Study Phase
The handbook's reference list is long, and reading it passively will not help. Use each source with a specific exam question in mind.
Regulations
- Asbestos (40 CFR 763, 40 CFR 61 Subpart M, 29 CFR 1926.1101): separate the EPA rules from the OSHA worker-protection rule, and note what each one is primarily about.
- Lead (40 CFR 745, 29 CFR 1926.62): distinguish the lead-based-paint provisions from the construction-industry worker standard.
- Hazardous materials (29 CFR 1910.120): focus on how hazardous-waste operations and emergency response requirements shape worker training and protection.
Guidance documents
- NIOSH Respirator Selection Logic (October 2004): practice walking a scenario through the decision logic from hazard to respirator choice.
- NYC fungi-remediation guidance (2008): study how remediation scale relates to containment and protection.
- EPA methamphetamine laboratory cleanup guidance: ACAC names the methamphetamine laboratory cleanup guidelines without an edition. EPA's current PDF is titled for methamphetamine and fentanyl laboratory cleanup (revised August 2021), but that expanded title does not establish that ACAC adopted that edition or that fentanyl is within CRER exam scope.
Also be aware that two legacy links in the handbook, the Region 5 mercury PDF and the NYC mold guidance, could not be retrieved. Their assignments and titles are verified in the issuer handbook, so search for the documents by title if the links fail.
CRER Compared With Related Credentials
Candidates often weigh the CRER against neighboring ACAC credentials. A few verified contrasts: CRER does not carry the two-year experience route associated with CIER, and it does not require a degree. For the detailed side-by-side, including CRMR, check the credential-specific pages on ACAC's site and compare handbook scopes directly rather than relying on summaries.
Certification versus licensing deserves its own warning. Certification is awarded to individuals. Passing an examination used only for state licensing does not authorize the CRER designation and does not replace jurisdiction-specific licensing requirements. If your state licenses remediators, consult that jurisdiction's official source.
Sequencing Your Preparation
Because ACAC publishes no weights, spread effort evenly at first, then shift toward your weakest group after a diagnostic. A practical order puts the regulatory-heavy groups first so the citations become familiar before you meet scenarios that depend on them. Pair this with the full CRER study guide and the one-page cheat sheet for final review.
Asbestos and lead
- Read 40 CFR 763, 40 CFR 61 Subpart M, 29 CFR 1926.1101, 40 CFR 745 and 29 CFR 1926.62
- Build a table of engineering controls, cleaning methods and worker protections for each
Hazardous materials and chemicals
- Work through 29 CFR 1910.120, both mercury references, and the meth-lab cleanup guidance
- Practice respirator selection with the NIOSH logic
Microbial contaminants and allergens
- Study the NYC fungi guidance and moisture-source correction
- Take timed question sets in the two-hour, 50-question format
When you are ready to test yourself under realistic conditions, use the CRER practice test to drill scenario questions across all five groups, and revisit the practice question bank for weak spots.
Frequently Asked Questions
CRER stands for Council-certified Residential Environmental Remediator, a credential issued by the American Council for Accredited Certification (ACAC). See What Is CRER Certification? for more.
The CRER handbook specifies 50 multiple-choice questions with at least four answer choices, closed book, in two hours. The passing criterion is 70%.
The initial US/Canada fee is USD 400, covering the USD 100 examination and the USD 300 vocational certification for the first two years. Retakes are USD 100, and renewal is USD 300 plus 40 recertification credits.
Yes. Delivery is available at a testing center or online with video proctoring, and instructor-proctored vocational examinations are offered through ACAC arrangements. Online candidates need an approved webcam, a private location and a continuous 2 Mbps connection.
No. Certification is awarded to individuals, and passing an exam for licensing alone does not authorize the CRER designation or replace jurisdiction-specific licensing requirements.