What the EPA 608 Core exam covers
Core is the gate. Every EPA 608 credential — Type I, II, III, and Universal — starts here, and you cannot earn any of them until you pass Core first. It is 25 questions on the rules that apply no matter what system you touch.
At its heart: Section 608 of the Clean Air Act prohibits venting refrigerants that harm the stratospheric ozone layer. The Core exam checks that you understand why those rules exist and how they play out on a real service call. The five topics below are exactly what the proctored exam draws from — and what the 50 questions above drill you on.
The Core section covers five knowledge areas:
- Environmental impact: Ozone Depletion Potential (ODP) and Global Warming Potential (GWP) for each refrigerant family. The 1987 Montreal Protocol and the 1990 Clean Air Act Amendments drove phase-out schedules for CFCs and HCFCs; the 2020 AIM Act now phases down HFCs.
- Recovery, recycling, and reclamation: These three terms have distinct legal meanings. Recovery means removing refrigerant from a system into an external container. Recycling means cleaning refrigerant for reuse on-site. Reclamation means processing to ARI 700 standard by an EPA-approved reclaimer.
- Evacuation and dehydration: Deep vacuum requirements (measured in inches of mercury or microns) before recharging a system. Core tests both pre- and post-1993 recovery equipment standards.
- Safety: Cylinder color codes, pressure-relief valve requirements, oxygen deprivation risks, and refrigerant toxicity classifications (A1, A2L, B1, B2L).
- Regulatory compliance: Maximum civil penalties exceed $44,539 per day per violation for illegal venting. Technicians must retain service records for a minimum of 3 years.
A note on where these questions come from: we built our 569-question bank from official ESCO study materials and checked every number against 40 CFR Part 82 on eCFR. Each question also passes a 3-layer check — a structure check, a fact check against our verified facts table (every fact carries a source citation), and an explanation review — before it goes live.
Refrigerant families: CFC, HCFC, HFC, HFO
Expect at least a few questions asking you to tell these four generations apart. The shortcut: phase-out tracks ozone damage — the higher the ODP, the sooner it was banned. Note the twist in the table below: HFCs have zero ODP but a high GWP, which is why the AIM Act is phasing them down anyway.
| Family | Example | ODP | GWP | Status (2026) |
|---|---|---|---|---|
| CFC | R-11, R-12 | High (1.0) | High | Fully phased out |
| HCFC | R-22, R-123 | Low (0.055) | Moderate | Production ended 2020 |
| HFC | R-410A, R-134a | Zero | High (2,088) | AIM Act phase-down in progress |
| HFO | R-1234yf | Zero | Very Low (4) | Current transition target |
Recovery methods, evacuation levels, and cylinders
This cluster trips up more Core candidates than any other, and it shows up on the exam again and again. Nail the two recovery methods, the evacuation targets, and the cylinder rules and you have covered a big slice of the test. Drill them fast with the EPA 608 cheat sheet.
The two recovery methods
EPA 608 recognizes exactly two methods of refrigerant recovery — not three:
- System-dependent (passive) recovery — equipment that requires the appliance's own components (such as its compressor) to push the refrigerant out. Used mainly on small appliances (5 lbs or less).
- Self-contained (active) recovery — equipment that pulls the refrigerant out on its own, without help from the appliance. Required for larger and high-pressure systems.
Small appliances: how much you must recover
When recovering from a small appliance you must capture:
- 90% of the charge when the appliance's compressor is operating, or
- 80% when the compressor is not operating or you use self-contained equipment — or evacuate the appliance to 4 inches of mercury vacuum using recovery equipment certified after November 15, 1993.
Required evacuation levels for larger appliances
For appliances other than small appliances, 40 CFR Part 82 sets the vacuum you must pull, and it depends on the appliance type and whether your recovery equipment was made before or on/after November 15, 1993:
| Appliance type | Equip. before Nov 15, 1993 | Equip. on/after Nov 15, 1993 |
|---|---|---|
| HCFC-22 (or similar), under 200 lbs | 0 in. Hg | 0 in. Hg |
| HCFC-22 (or similar), 200 lbs or more | 4 in. Hg | 10 in. Hg |
| Other high-pressure (CFC-12, -500, -114), under 200 lbs | 4 in. Hg | 10 in. Hg |
| Other high-pressure (CFC-12, -500, -114), 200 lbs or more | 4 in. Hg | 15 in. Hg |
| Very high-pressure (CFC-13, -503) | 0 in. Hg | 0 in. Hg |
| Low-pressure (CFC-11, HCFC-123) | 25 in. Hg vacuum | 25 mm Hg absolute |
The figure most people miss: low-pressure appliances (R-11, R-123) require 25 mm Hg absolute with post-1993 equipment — a deep vacuum, not "25 inches of mercury."
Recovery cylinder rules
- Never fill a recovery cylinder above 80% of capacity — leave room for the liquid to expand (cylinders are rated to 130°F).
- Use a DOT-approved recovery cylinder.
- Recovery cylinders carry a gray body with a yellow top (the DOT/industry color code).
The recovery and evacuation rules come straight from 40 CFR Part 82, Subpart F (cylinder specs from DOT) — the same regulations every verified answer on this page is checked against.
Passing the EPA 608 Core section
You pass Core at 72% — 18 of 25 correct (how the passing score works). Two topics trip up the most people: the recovery, recycling, and reclamation definitions (they sound interchangeable, but each has a distinct legal meaning) and evacuation vacuum levels (know your micron targets). If you score under 18/25 on the practice test above, retake it focused on those two — they are also the topics most likely to cost you a point on exam day. With a free account, the weak-spot chart shows which of these topics is actually costing you points — and flashcards are free for every section. Pro adds a targeted drill that serves only the questions you keep missing.
Before taking the test, review the EPA 608 Core section study guide. It covers venting prohibition dates, civil penalty amounts, the de minimis exemption, and the refrigerant lifecycle from recovery through reclamation.
If an explanation above still does not click, the AI Tutor in the app breaks the concept down in plain trade language — free accounts get 10 AI questions a month, Pro gets 1,000.
Once passed, Core certification does not expire. It is a permanent part of your Section 608 technician credential. Continue with the Type I Small Appliance practice test, Type II High-Pressure practice test, or Type III Low-Pressure practice test, or jump to the EPA 608 Universal practice test when you are ready to simulate the full 100-question proctored exam. For in-depth topic coverage, visit our EPA 608 study guide collection.
Frequently asked questions
The Core section has 25 multiple-choice questions. You need 18 of 25 correct (72%) to pass. Core is required before you can earn any Type I, II, III, or Universal certification.
72%, which is 18 out of 25 correct answers. The official proctored exam is administered closed-book by EPA-approved organizations such as ESCO Institute and Mainstream Engineering.
The Core exam covers the Montreal Protocol and Clean Air Act, ozone depletion from CFCs and HCFCs, refrigerant safety (cylinder colors, toxicity ratings, oxygen deprivation), recovery vs. recycling vs. reclamation, deep vacuum/evacuation requirements, and civil penalties for illegal venting.
Yes. All on-page Core questions with instant scoring and explanations are completely free with no signup. Create a free account to save your scores, track progress across sessions, and access all 569 verified questions in the full question bank. Pro ($14.99 lifetime) unlocks AI Tutor (1,000 questions/month), weak-spot drills, the weak-spot radar, timed exam simulation, and offline access.
No. Core certification is permanent once earned. It does not require renewal or re-testing.
Yes. The Core exam directly tests knowledge of the Montreal Protocol (signed 1987) and how it drove the phase-out of CFCs and HCFCs under the U.S. Clean Air Act.
Start with the EPA 608 Core study guide, then use this practice test to identify gaps. Focus on recovery/reclamation definitions, evacuation micron levels, refrigerant families (CFC/HCFC/HFC/HFO), and penalty amounts. Repeat this practice test until you consistently score 72% or higher (on the real 25-question exam that means 18 of 25).
The EPA can impose civil penalties of up to $44,539 per day per violation for knowingly venting refrigerants covered under Section 608. The Core exam tests awareness of this penalty and the venting prohibition rules.
Some EPA-approved providers offer online proctored testing. Check our guide on online and in-person testing options for current providers and availability.
Core covers the rules that apply to every refrigerant technician regardless of equipment — venting law, recovery/recycling/reclaiming, refrigerant families, and safety. The Type sections add equipment-specific knowledge: Type I (small appliances), Type II (high-pressure systems), and Type III (low-pressure systems). You must pass Core plus at least one Type to be certified; pass Core and all three Types and you earn Universal.
Yes. If you do not pass Core, most EPA-approved testing organizations let you re-test (often for an additional fee, sometimes after a short wait). Because each section is scored separately, you only need to retake the section you did not pass — not the whole exam.