Complete EPA 608 Study Guide [2026 Edition] (EPA 608 Practice Test)

This complete EPA 608 study guide covers every section you need to pass — from Core fundamentals to Type I, II, III, and Universal certification. It's the free online resource that physical study books don't offer: all types in one place, updated for 2026 AIM Act changes, with direct links to free EPA 608 Practice Test tools for every section. For a structured study schedule and daily method, see how to study for the EPA 608 exam. To maximize retention from any study guide, apply proven study methods like active recall and wrong-answer tracking throughout your preparation.

How to Use This Study Guide — EPA 608 Practice Test

This guide is structured to mirror the exam itself. Read each section in order, then immediately take the corresponding free practice test to test your knowledge. Don't try to memorize everything in one sitting — study one type per day and let practice tests reveal your gaps.

Recommended approach:

1. Read a section fully — don't skim
2. Study the Key Numbers table for that type
3. Take the practice test (link at each section)
4. Write down every wrong answer and understand why
5. Retake the test the next day — aim for 80%+ before exam day

Core Section: What Every Technician Must Know

The Core section is required for every EPA 608 certification — whether you're taking Type I alone or going for Universal. It covers federal refrigerant regulations, ozone science, and recovery rules that apply across all systems. Master Core first.

Clean Air Act and Section 608 Basics

The EPA 608 certification exists because of Section 608 of the Clean Air Act, which prohibits knowingly venting refrigerants into the atmosphere. The specific regulations are codified in 40 CFR Part 82, Subpart F. Key legal facts the exam tests:

• It is illegal to knowingly vent CFC, HCFC, or HFC refrigerants — all are covered
• Technicians who purchase refrigerant in containers larger than 2 lbs must be EPA 608 certified
• Refrigerant must be recovered before opening or disposing of refrigerant-containing equipment
• Employers cannot knowingly allow uncertified technicians to perform work that could release refrigerant
• Violations can result in fines of up to $44,539 per day per violation

Ozone Depletion (ODP) and Global Warming Potential (GWP)

The exam tests your understanding of two environmental impact metrics:

Metric	What it measures	Refrigerants most affected
ODP (Ozone Depletion Potential)	Harm to stratospheric ozone layer	CFCs (R-11, R-12) highest; HCFCs (R-22) moderate; HFCs = 0
GWP (Global Warming Potential)	Contribution to climate change	HFCs very high (R-410A GWP: 2,088); HFOs very low

Key distinction: HFCs like R-410A have zero ODP (good for ozone) but very high GWP (bad for climate). This is why the AIM Act is phasing them down.

Refrigerant Recovery Rules

Recovery requirements vary by system pressure and equipment type. These numbers are tested directly:

• High-pressure systems: 90% recovery required (when using recovery equipment manufactured before November 15, 1993: 80%)
• Low-pressure systems (chillers): 80% recovery or 25 in Hg vacuum
• Very high-pressure systems (>400 psia): 0% (recovery not required — these systems self-purge)
• Recovery equipment must be certified by an EPA-approved equipment testing organization (ETL)
• Recovered refrigerant must be sent to a certified reclaimer or reused in same owner's equipment

2026 AIM Act and A2L Refrigerant Updates 2026

The American Innovation and Manufacturing (AIM) Act of 2020 is now creating real changes to EPA 608 exam content. Expect questions on:

• HFC phasedown: U.S. HFC production and consumption phased down 85% by 2036 from baseline
• R-410A new installations: Restricted starting January 1, 2025 for new residential and light commercial AC systems
• A2L refrigerants: Mildly flammable class (lower flammability limit >0.10 kg/m³). Examples: R-32, R-454B, R-466A
• Safe handling of A2L: No open flame near leaks, enhanced ventilation, new leak detection requirements
• R-454B (Opteon XL41): Low GWP replacement for R-410A in new equipment

Take the Core practice test now: EPA 608 Core Practice Test — Free

Type I Study Guide — Small Appliances

Type I certification covers small appliances — equipment manufactured, charged, and hermetically sealed at the factory with 5 pounds or less of refrigerant. This is the smallest and generally easiest Type section, but the exam does test specific technical rules.

What Systems Are Covered

• Household refrigerators and freezers
• Room air conditioners (window units)
• Packaged terminal air conditioners (PTACs)
• Vending machines, water coolers, drinking fountains
• Dehumidifiers

Key Type I Rules to Memorize

• 5 lb threshold: Small appliances contain ≤5 lbs of refrigerant (factory charge)
• Passive recovery: Allowed — the system's own compressor can be used to recover refrigerant without an external recovery device
• Active recovery: Required when the system's compressor is not operational — must use an EPA-approved recovery device
• Piercing valves: Once attached to a system, piercing valves must remain on the system after service
• Recovery target: 90% of refrigerant in the system (or 80% if recovery equipment is pre-1993)

Scenario	Recovery Method
Compressor is working	Passive recovery (system compressor)
Compressor not working	Active recovery (EPA-approved device)
System already fully recovered	No additional recovery needed

Take the Type I EPA 608 Practice Test — Free

Type II Study Guide — High-Pressure Systems (EPA 608 Practice Test)

Type II is the most common certification — and the hardest section. High-pressure systems include all the equipment HVAC technicians work with most often: split systems, rooftop units, and the refrigerants that are transitioning under AIM Act. Allocate the most study time here.

What Systems Are Covered

• Residential and commercial split systems (R-410A, R-22)
• Rooftop packaged units
• Heat pumps
• Refrigeration systems using R-134a, R-404A, R-407C
• New systems using R-454B, R-32 (A2L transition refrigerants)

Key Type II Rules to Memorize

• Vacuum level target: 500 microns (or per equipment manufacturer — whichever is more stringent)
• Recovery rate: 90% of system refrigerant charge required
• Commercial leak rate: 15% per year triggers required repair
• Industrial leak rate: 35% per year triggers required repair
• R-410A operating pressures: ~400 psig high side at 95°F ambient (significantly higher than R-22 ~250 psig) — pressures matter for safe handling
• Nitrogen pressurizing: Use dry nitrogen for leak testing — never use oxygen or refrigerant alone
• System evacuation sequence: Recovery first → repair → evacuate → recharge

Take the Type II EPA 608 Practice Test — Free

Type III Study Guide — Low-Pressure Systems

Type III covers low-pressure systems — primarily large commercial chillers found in office buildings, hospitals, and industrial facilities. These systems operate below atmospheric pressure (in a vacuum), which creates unique safety and recovery challenges different from all other refrigerant systems.

What Systems Are Covered

• Centrifugal chillers using R-123 or legacy R-11
• Any refrigerant system with evaporator pressure below 0 psig at 40°F
• Large commercial and industrial cooling plants

Key Type III Rules to Memorize

• Evacuation level: 25 inches Hg vacuum (measured on vacuum gauge, not micron gauge)
• Recovery rate: 80% of system refrigerant charge, or evacuate to 25 in Hg
• Rupture disc: 15 psi is the standard rupture disc pressure for low-pressure chiller systems
• Purge units: Low-pressure systems use purge units to remove non-condensables (air/moisture) — purge unit emissions must be recovered or destroyed
• Leak rates: Differ from high-pressure — low-pressure systems allow up to 35% per year (industrial) before mandatory repair
• Operating pressure: R-123 operates at -3 to -8 psig in the evaporator — below atmospheric; air can be drawn into leaks
• Non-condensables: The biggest hazard for low-pressure systems is air infiltration causing pressure issues and compressor damage

Take the Type III EPA 608 Practice Test — Free

Universal Certification — EPA 608 Practice Test Study Path

Universal certification means you've passed all four sections: Core, Type I, Type II, and Type III. It's the most valuable certification for commercial HVAC technicians because it lets you work on any refrigerant system without restriction. Study path for Universal follows the same sections above, but you take all sections in one sitting.

Universal Study Strategy

1. Start with Core — it's required and builds regulatory foundation for everything else
2. Do Type II second — hardest section, needs most time, most job-relevant
3. Do Type I third — easiest section, builds confidence
4. Do Type III last — unique concepts, but logical once you understand recovery principles
5. Run Universal simulations — take all 4 practice tests back-to-back to simulate the real exam day

Take the Universal EPA 608 Practice Test — Free

Key Numbers to Memorize — EPA 608 Practice Test Cheat Reference

The EPA 608 exam is closed-book. These numbers appear on the exam directly. Do not leave this page until these are in memory — they are the most commonly tested values across all sections.

Fact	Value	Section
Passing score	70% (18 out of 25 questions)	All
Questions per section	25	All
Small appliance refrigerant threshold	5 lbs or less (factory charge)	Type I
High-pressure vacuum target	500 microns	Type II
Low-pressure evacuation level	25 inches Hg	Type III
Recovery rate — high-pressure systems	90% (80% if pre-1993 equipment)	Type II
Recovery rate — low-pressure systems	80% or 25 in Hg	Type III
Commercial leak rate trigger	15% per year	Type II
Industrial leak rate trigger	35% per year	Type II/III
Low-pressure rupture disc	15 psi	Type III
Max fine per violation per day	$44,539	Core
Refrigerant purchase minimum (cert required)	Containers >2 lbs	Core
Certification validity	Lifetime — no expiration	All
R-410A GWP	2,088	Core/Type II
R-454B GWP (replacement for R-410A)	466	Core/Type II

For a printable version of these numbers, see the EPA 608 Study Guide Cheat Sheet and EPA 608 Cheat Sheet.

Study Schedule — 1-Week and 2-Week Plans

Use whichever plan matches your timeline. Both assume 2–3 hours of focused study per day. If you're going for Universal, use the 2-week plan.

1-Week Plan (Core + One Type)

Day	Focus	Practice Test
Day 1	Core: Clean Air Act, Section 608, ODP/GWP basics	—
Day 2	Core: Recovery rules, AIM Act, A2L intro	Core Practice Test
Day 3	Your Type: Key rules, key numbers, system overview	—
Day 4	Your Type: Edge cases, leak rates, equipment rules	Take your Type test
Day 5	Review all wrong answers from Days 2 + 4	Retake both tests
Day 6	Key numbers memorization drills	Take both tests again
Day 7	Rest or light review only — don't cram	Final confidence check

2-Week Plan (Universal — All 4 Sections)

1. Days 1–2: Core SectionClean Air Act, ODP/GWP, recovery rules, AIM Act 2026. Take Core practice test on Day 2.
2. Days 3–5: Type II (Hardest First)High-pressure systems, R-410A, vacuum levels, leak rates, A2L transition. Take Type II practice test on Day 5.
3. Days 6–7: Type ISmall appliances, 5-lb rule, passive vs active recovery, piercing valves. Take Type I practice test on Day 7.
4. Days 8–9: Type IIILow-pressure chillers, R-123, 25 in Hg, purge units, 15 psi rupture disc. Take Type III practice test on Day 9.
5. Days 10–12: Review Weak SpotsIdentify sections where you scored below 80%. Return to those sections in this guide. Retake those practice tests.
6. Days 13–14: Full Universal SimulationTake all 4 practice tests back-to-back without breaks. Score 80%+ on all 4 before booking your real exam.

Practice Test Links — Test Your Knowledge

Each section of this study guide maps directly to one of these free EPA 608 Practice Test tools. No signup required — start immediately.

Frequently Asked Questions — EPA 608 Practice Test