- What the Published Data Actually Says About CIRO Pass Rates
- Reading the 58% Figure Correctly
- How the Exam Is Built: 135 Questions, 70% to Pass
- What the Study Guide's Item Counts Tell You (and Don't)
- The Experience Filter Before You Ever Sit
- Fees, Practice Attempts and the Cost of a Retest
- Domain-by-Domain Readiness for the Eight Content Areas
- Sequencing Your Preparation Around the Domains
- Who Values the Credential
- Frequently Asked Questions
- RETA does not publicly disclose a current overall CIRO pass rate in the sources reviewed for this article.
- The only rate RETA reports is a historical 58%, limited to candidates who used a practice test in the first half of 2024.
- The live exam has 135 multiple-choice questions, 125 scored and ten unscored, with three hours and a 70% passing score.
- The 2026 exam fee includes one 70-question official practice exam; extra practice attempts cost $59.
What the Published Data Actually Says About CIRO Pass Rates
Search for "CIRO pass rate" and you will find confident-sounding numbers on forums and aggregator sites. Treat them cautiously. For the Certified Industrial Refrigeration Operator credential, administered by the Refrigerating Engineers & Technicians Association (RETA), the honest answer is that a current overall pass rate is not publicly disclosed in the sources we located. No annual pass-fail table, no rolling percentage, and no first-time versus repeat-taker breakdown appears in the reviewed public materials.
That gap matters because several other credentials share the "CIRO" acronym, and pass-rate claims from those programs have a way of drifting onto the wrong page. Everything on this page concerns the Certified Industrial Refrigeration Operator exam only. If you are still orienting yourself, our explainer on what CIRO certification is covers the credential's scope before you worry about the statistics.
Reading the 58% Figure Correctly
The single published number is a 58% pass rate that RETA reports for CIRO candidates who used a practice test in the first half of 2024. Three qualifiers in that sentence do a lot of work:
- It is a subgroup. It covers candidates who took a practice test, not everyone who sat for the exam.
- It is historical. It reflects the first half of 2024, not 2026 testing.
- It is not a global rate. You cannot infer from it what happens to candidates who skipped the practice exam.
It would be tempting to read 58% as "the" pass rate, or to assume non-practice-test takers do worse. Neither inference is supported by the data. What the figure does tell you is that even among candidates who took the trouble to simulate the exam, a meaningful share did not clear the 70% passing score. That is a sober signal: practice-test use is not a guarantee, and the exam rewards real command of the material over familiarity with the format.
For a fuller view of difficulty, see How Hard Is the CIRO Exam?, which frames the challenge in terms of content rather than a single statistic.
How the Exam Is Built: 135 Questions, 70% to Pass
Pass-rate discussions are only useful if you understand what is being passed. The structural facts are:
| Feature | CIRO Detail |
|---|---|
| Question format | Multiple choice |
| Total questions | 135 (125 scored, 10 unscored) |
| Time allowed | Three hours |
| Passing score | 70% |
| Content areas | Eight |
| Delivery | RETA with RETA Network and Kryterion Test Centers; staff-managed scheduling |
| Permitted at the test | Issuer on-screen references and a basic calculator; two IDs required |
| Not permitted | Personal study guides |
Three hours for 135 questions works out to well over a minute per item, which is workable for recall questions but tighter for calculation-heavy ones. Because a basic calculator is allowed and issuer on-screen references are available, the exam leans toward applied problem-solving: reading a gauge scenario, working a heat-flow figure, or reasoning through a control sequence. You cannot bring your own notes, so the references on screen are the only help you get, and you should learn how they are organized before test day.
Note that live remote availability and whether the exam is adaptive were not verified in the sources reviewed. Confirm both directly with RETA when you schedule. For the scoring details, the CIRO passing score guide goes deeper, and the CIRO exam dates guide covers scheduling.
What the Study Guide's Item Counts Tell You (and Don't)
The official RETA CIRO Study Guide lays out the eight content areas along with item counts for each. Those counts, in order, are 20, 15, 15, 20, 20, 20, 15 and 10 total items. They include the ten unscored items, which are distributed across the areas.
| Domain | Total Items (including unscored) |
|---|---|
| Domain 1: Safety Standards and Practices | 20 |
| Domain 2: Electricity | 15 |
| Domain 3: Heat Flow | 15 |
| Domain 4: Monitoring System Performance | 20 |
| Domain 5: Valves, Controls and DX Systems | 20 |
| Domain 6: Liquid Overfeed and Flooded Systems | 20 |
| Domain 7: Two-Stage and Secondary Coolant Systems | 15 |
| Domain 8: Evaporator Defrost | 10 |
This is relevant to pass-rate thinking because candidates often try to game the exam by concentrating on the "biggest" domains. With a 70% bar across 125 scored questions, you need roughly 88 correct answers, and a weak showing in any one area can sink a score. For a walkthrough of each area, see the CIRO exam domains guide.
The Experience Filter Before You Ever Sit
One reason a raw pass rate would be hard to interpret even if RETA published it: the candidate pool is pre-filtered. To be eligible, you need at least two years of industrial refrigeration operation or technician experience, plus a separate verification of experience (VOE) signed by a supervisor, manager or colleague. The reviewed requirements do not list a degree, a CARO prerequisite, a fixed training-hour total, or additional references.
In practice that means the people taking the exam already work around ammonia and halocarbon systems, compressors, evaporators and controls. A pass rate for such a group says less about "how hard is this generally" and more about how well daily plant experience maps to the written exam. Operators who are excellent on the plant floor can still stumble on the formal vocabulary, the electrical theory, or the structured safety-standards questions. Our CIRO requirements guide walks through eligibility in detail.
Fees, Practice Attempts and the Cost of a Retest
Since no overall pass rate is published, the more practical way to think about risk is cost. The 2026 fee structure:
- Exam fee: $570 for RETA members, $865 for non-members. This includes one 70-question official practice exam.
- Additional practice attempts: $59 each.
- Eligible retest fee: $380 for members, $580 for non-members.
Do the arithmetic and a failed first attempt followed by a retest brings a member's exam spend to $950 and a non-member's to $1,445, before study materials or time off work. The membership discount alone is $295 on the initial fee, which is worth weighing if you are not already a RETA member. For the complete breakdown including renewal, read the CIRO certification cost guide.
Key Takeaway
Use the included 70-question official practice exam diagnostically, not as a last-minute confidence check. Take it early enough that its results can redirect your remaining study across the eight domains, and treat the $59 extra attempts as cheap insurance compared with a $380 or $580 retest.
Domain-by-Domain Readiness for the Eight Content Areas
Because the passing standard is a single 70% across the whole exam, your readiness should be assessed domain by domain. The following blocks flag where operators commonly need to shore up the written side of their knowledge.
Domain 1: Safety Standards and Practices
Often the most familiar area to working operators, but the exam tests standards-based reasoning, not just habit.
- Know the rationale behind safe operating and emergency procedures, not only the steps.
- Be able to apply safety principles to scenario-style questions.
Domain 2: Electricity
A frequent weak spot for operators who rely on electricians for troubleshooting.
- Review basic circuit relationships and how motors and controls draw and respond to power.
- Practice problems where the basic calculator is useful.
Domain 3: Heat Flow
The conceptual core underneath every other area.
- Be fluent in how heat moves through a refrigeration cycle.
- Connect heat-transfer ideas to what you see on gauges and in the machinery room.
Domain 4: Monitoring System Performance
Reading the plant as a system rather than as separate parts.
- Interpret operating conditions to judge whether a system is running normally.
- Recognize what abnormal readings imply.
Domain 5: Valves, Controls and DX Systems
Component identification and control logic, including direct-expansion systems.
- Know what each valve and control does and how it fits into a sequence.
- Be ready for questions that trace a fault to a specific component.
Domain 6: Liquid Overfeed and Flooded Systems
System types some candidates meet only on one kind of site.
- If your plant is DX-heavy, deliberately study overfeed and flooded configurations.
Domain 7: Two-Stage and Secondary Coolant Systems
Multi-stage compression and indirect cooling, again often site-dependent.
- Understand why these configurations are used and how their components interact.
Domain 8: Evaporator Defrost
Smallest by item count, but a common source of procedural questions.
- Know the defrost methods and the sequencing that protects equipment.
One practical observation: the domains that depend on what kind of plant you work in (Domains 5, 6 and 7) are where experienced operators most often discover gaps. Someone who has spent years on a single system type has deep knowledge of it but may have never touched the others. That mismatch is a more plausible explanation for missed passes than a lack of general competence.
Sequencing Your Preparation Around the Domains
Since this is a technical exam with interlocking concepts, order matters. Build the foundations first, then layer on system-specific content, and save the safety and defrost material for review, where repetition pays off.
Foundations: Electricity and Heat Flow
- Work Domains 2 and 3 first, since they underpin the rest.
- Take the included 70-question practice exam to locate weak areas.
Systems: Domains 4 through 7
- Cover monitoring, valves and controls, overfeed and flooded, and two-stage and secondary coolant systems.
- Spend extra time on any system type your own plant does not use.
Safety, Defrost and Full Review
- Revisit Domain 1 and Domain 8.
- Re-test with a further practice attempt and learn the layout of the on-screen references.
For a fuller plan, see the CIRO study guide, and for a compressed last-pass review use the CIRO cheat sheet. You can also drill questions on our practice test site to gauge where you stand across all eight areas before you book.
Who Values the Credential
A pass rate is only meaningful if the credential is worth earning. The Certified Industrial Refrigeration Operator designation is aimed at people who run and maintain industrial refrigeration systems, so the employers who care are those with large refrigeration plants: food and beverage processors, cold storage and distribution warehouses, and similar facilities that depend on ammonia or other industrial refrigerants. For these employers, a RETA credential offers a recognized, third-party signal of operator competence, which can matter for staffing, insurance and safety programs.
Certification is valid for three years. Renewal requires 24 approved professional development hours (2.4 CEUs) recorded in the RETA Certification Database, along with a renewal fee of $180 for members or $635 for non-members. That recurring commitment is part of the real cost of holding the credential. If you are weighing the payoff, our guides on whether the certification is worth it, earnings and CIRO jobs go into the career side.
Frequently Asked Questions
A current overall pass rate is not publicly disclosed in the sources located. RETA reports only a historical 58% rate for CIRO candidates who used a practice test in the first half of 2024, which should not be read as the overall rate.
The passing score is 70%. The exam has 135 multiple-choice questions, of which 125 are scored and ten are unscored, and you have three hours to complete it.
The posted eligible retest fee is $380 for RETA members and $580 for non-members. Additional practice exam attempts beyond the one included with your exam fee cost $59 each.
No. The guide's counts of 20, 15, 15, 20, 20, 20, 15 and 10 include ten unscored items spread across the areas, so they do not establish scored-domain weights. Prepare for all eight content areas.
You need at least two years of industrial refrigeration operation or technician experience and a separate verification of experience signed by a supervisor, manager or colleague. The reviewed requirements do not list a degree or a fixed training-hour total.