What each EPA 608 section tests
Pick the section you are sitting. Each practice test gives you 25 questions with an explanation on every answer, and the same page answers that section's most searched exam questions.
Core (required for every certification)
The federal rules behind every other section: the venting ban, recovery, recycling and reclaim, recovery cylinders and the civil penalty.
Topics: venting ban and its exemptions · recovery steps and cylinders · reclaim to AHRI 700
Type 1: small appliances
Appliances sealed at the factory with 5 lb of refrigerant or less, such as household refrigerators and window air conditioners.
Topics: recovery levels (90%, 80% or 4 in. Hg) · system-dependent and self-contained recovery · hydrocarbon refrigerators
Type 2: medium-, high- and very high-pressure appliances
Split-system air conditioning, heat pumps and commercial refrigeration.
Topics: leak-rate triggers (10%, 20%, 30%) · the 30-day repair clock · evacuation levels by pressure class
Type 3: low-pressure chillers
Chillers that run below atmospheric pressure, on refrigerants such as R-123 and R-11.
Topics: the 25 mm Hg absolute recovery level · purge units and leaks · nitrogen leak tests at 10 psig or less
Universal: all four sections
100 questions in one exam, 25 per section. Certifying organizations grade each section on its own.
EPA 608 cheat sheet
Every number and rule the four sections test, on one page. The common wrong answer on each row is one you will meet: a value older study materials still print, or the neighboring number the exam pairs it with. Checked against 40 CFR Part 82 in November 2026. The date on the PDF tells you which version you have.
The exam itself
| Number or rule | What it means | Common wrong answer |
|---|---|---|
| 25 per section | Core, Type 1, Type 2 and Type 3 each have 25 questions. Universal is all 100 | |
| 18 of 25 | Pass mark on every proctored section (the certifying organizations' grading) | 21 of 25, which is the mail-in Type 1 mark |
| 21 of 25 | Pass mark on the open-book, mail-in Type 1 test. A mail-in Type 1 pass can't be used for Universal | 18 of 25 |
| Open-book Core | Some organizations offer it, but it can't be used for Universal certification | "Counts the same as proctored Core" |
| Never expires | Section 608 certification is a lifetime credential | A renewal every few years |
| 608 vs 609 | 608 covers stationary equipment. 609 covers motor vehicle air conditioning |
Core: the law, recovery and cylinders
| Number or rule | What it means | Common wrong answer |
|---|---|---|
| July 1, 1992 | The venting ban on CFC and HCFC refrigerants takes effect | November 15, 1995 |
| November 15, 1995 | The venting ban covers substitutes such as HFCs, R-410A included (CAA §608(c)(2)) | July 1, 1992 |
| 1987 | Montreal Protocol signed (September 16, 1987) | |
| $124,426 | Maximum civil penalty per day, per violation (40 CFR 19.4, penalties assessed from January 8, 2025) | $44,539, an older administrative figure some guides still print |
| De minimis | Small releases during a good-faith recovery attempt that follows the required practices, with certified equipment, are not a violation. The rule names no amount | A fixed ounce or pound limit |
| CO2, nitrogen, water | May be vented in any application. Ammonia only in commercial, industrial process or absorption systems | "CO2 is exempt because it is a very high-pressure gas" |
| Recovery order | Identify the refrigerant, use a certified recovery machine and a one-refrigerant cylinder, take liquid first, then vapor to the required level, and stop at 80% full | Mixing two refrigerants in one cylinder |
| 80% by weight | Fill limit for a recovery cylinder (AHRI Guideline K, industry guidance) | 90%, which is a Type 1 recovery level |
| Refillable DOT cylinder | Recovery cylinders are refillable DOT cylinders, gray with a yellow top by the Guideline K color code (a guideline, not law) | A disposable (DOT 39) cylinder |
| Every 5 years | Requalification of a refillable recovery cylinder (AHRI Guideline K, citing 49 CFR Part 180) | |
| AHRI 700 | Purity standard for reclaimed refrigerant. Needed before recovered refrigerant is sold to a different owner | "Recycled refrigerant can be sold to another owner" |
| Same owner | Recovered refrigerant can go back into the same appliance, or another one the same person owns, without reclaim (§82.156(h)) | "Every recovered charge must be reclaimed" |
| November 15, 1993 | Recovery and recycling equipment made on or after this date must be certified by an EPA-approved testing organization (§82.158). Older equipment is grandfathered if it meets Table 2 | |
| 45 psia at 104°F | Pressure classes go by liquid saturation pressure at 104°F: low below 45 psia, medium 45 to 170, high 170 to 355, very high above 355 (§82.152) | Classing by boiling point, the pre-2016 rule |
Refrigerant families and safety classes
| Refrigerant | Family | Safety class | What to know |
|---|---|---|---|
| R-11, R-12 | CFC | R-11 is low-pressure (Type 3). R-12 is medium-pressure (Type 2) | |
| R-22 | HCFC | Production and import ended January 1, 2020 | |
| R-123 | HCFC | Low-pressure. Still produced to service existing chillers until 2030 | |
| R-134a, R-410A | HFC, HFC blend | Under the venting ban since November 15, 1995. R-410A is still sold to service existing systems | |
| R-32, R-454B | HFC, HFC/HFO blend | A2L | Lower-GWP refrigerants in new air conditioning |
| R-290, R-600a | Hydrocarbon | A3 | May be vented only in listed end uses, such as household refrigerators |
| R-717 (ammonia) | Inorganic | B2L | Exempt from the venting ban only in commercial, industrial process or absorption systems |
Reading a safety class: the letter is toxicity (A lower, B higher) and the number is flammability (1 no flame spread, 2L lower flammability, 2 flammable, 3 highly flammable).
Type 1: small appliances
| Number or rule | What it means | Common wrong answer |
|---|---|---|
| 5 lb or less | A small appliance is fully manufactured, charged and hermetically sealed in a factory with 5 lb of refrigerant or less (§82.152) | Any unit with 5 lb or less, even one charged in the field |
| 90% | Recovery required with the compressor operating (recovery equipment made on or after November 15, 1993) | 80% |
| 80% | Recovery required with the compressor not operating, and with any recovery equipment made before November 15, 1993 | 90% |
| 4 in. Hg | The alternative: pull a 4 in. Hg vacuum instead of measuring the percentage | A mm Hg level, which is Type 3's unit |
| System-dependent recovery | Uses components contained in the appliance, such as its compressor, to move refrigerant into the container. Allowed on small appliances | "Only self-contained machines are allowed" |
| 150 g (5.3 oz) | Hydrocarbon charge limit per circuit in new household refrigerators, since September 7, 2018 | 57 g, the 2011 limit, or 2 lb |
| Disposal | Recovering refrigerant from a small appliance before disposal does not by itself require Section 608 certification | "Any refrigerant removal needs a Type 1 card" |
Type 2: leak rates and evacuation levels
| Number or rule | What it means | Common wrong answer |
|---|---|---|
| 50 lb | Leak repair rules cover appliances with 50 lb or more of CFC or HCFC refrigerant | 15 lb, which is the HFC trigger |
| 15 lb, GWP above 53 | Since January 1, 2026, AIM Act rules (40 CFR 84.106, not Section 608) apply similar leak repair rules to HFC appliances of 15 lb or more. Residential and light commercial AC and heat pumps are excluded | "Every R-410A system over 15 lb", home AC included |
| 10% | Leak-rate trigger for comfort cooling | 20% |
| 20% | Leak-rate trigger for commercial refrigeration | 10% |
| 30% | Leak-rate trigger for industrial process refrigeration | 35%, the pre-2019 threshold |
| 30 days | Repair deadline once the leak rate is over the trigger | 120 days, which needs an industrial process shutdown |
| 120 days | Repair deadline only when an industrial process shutdown is required | "Any owner can take 120 days" |
| 10 days | Follow-up verification test, within 10 days of a successful initial verification, for every appliance under the rules | "Only for systems of 200 lb or more" |
| 30 days, then 1 year | Retrofit or retirement plan: write it within 30 days, finish within 1 year | 18 months, which applies only when retiring and replacing with an exempt-refrigerant appliance |
| 0 psig | Before opening for a repair that is not major and is not followed by evacuating to the atmosphere. Also the floor for leaking parts that can't reach the table level | Pulling the table level for every repair |
Evacuation levels before a major repair or disposal (§82.156 Table 1)
| Pressure class | Under 200 lb | 200 lb or more |
|---|---|---|
| Very high-pressure | 0 in. Hg | 0 in. Hg |
| High-pressure (R-22, R-410A, R-407C, R-502) | 0 in. Hg | 10 in. Hg (4 in. Hg with recovery equipment made before November 15, 1993) |
| Medium-pressure (R-12, R-134a, R-500, R-114) | 10 in. Hg (4 in. Hg pre-1993) | 15 in. Hg (4 in. Hg pre-1993) |
Common wrong answers here: 15 in. Hg for a 200 lb R-502 system (that is the pre-2016 table; R-502 is high-pressure now, so 10 in. Hg), and any level written in psig.
Type 3: low-pressure chillers
| Number or rule | What it means | Common wrong answer |
|---|---|---|
| 25 mm Hg absolute | Recovery level for low-pressure appliances, the same for recovery equipment made before or after November 15, 1993 | Inches of Hg (Type 2's unit), or a shallower pre-1993 level |
| Below 45 psia | The low-pressure class: R-11, R-113, R-123, R-245fa | R-12, which is medium-pressure (Type 2) |
| 10 psig or less | Dry nitrogen pressure for a leak test | 15 psig, where the rupture disc bursts |
| 15 psig | The evaporator's rupture disc bursts here | 10 psig, the leak-test maximum |
| Purge unit | Removes air and other non-condensables that leak in, and the moisture that comes with them | |
| Excessive purging | A sign of a leak: the machine runs in a vacuum, so air leaks in | |
| R-123 | HCFC still produced for servicing existing chillers until 2030 | "Production ended in 2020", which is R-22 |
Three hooks for the numbers people swap
- 10, 20, 30 climbs with the load: comfort cooling, commercial refrigeration, industrial process.
- A running compressor can do more work: 90% when it operates, 80% when it doesn't.
- The unit names the section: in. Hg for Types 1 and 2, mm Hg absolute for Type 3.
EPA 608 practice questions and answers (PDF)
Ten of our practice questions are below with their answers. The PDF holds 100, 25 per section, each with the answer, a short explanation and the rule it comes from. We wrote them from ESCO Institute and SkillCat study materials and checked each one against 40 CFR Part 82. They are practice questions, not questions from the real exam.
Free, no email needed.
Using the PDF: answer one section's 25 without looking at the key, then mark yourself. 18 of 25 passes. For a timer and a score by topic, take the same sections online: Core · Type 1 · Type 2 · Type 3 · Universal.
What is the current maximum civil penalty per day, per violation, for violating the Clean Air Act (40 CFR 19.4, adjusted January 2025)?
- $124,426
- $37,500
- $69,733
- $472,901
Show answer
Answer: A. The current maximum Clean Air Act civil penalty is $124,426 per day, per violation, for penalties assessed on or after January 8, 2025. EPA adjusts it for inflation, so older guides show lower figures.
A recovery cylinder has a water capacity of 50 lb and a tare weight of 30 lb. The refrigerant's specific gravity is 1.10. Using the 80% safe-fill limit, what is the most the filled cylinder should weigh?
- 85 lb
- 70 lb
- 74 lb
- 44 lb
Show answer
Answer: C. Max gross weight = water capacity x specific gravity x 0.80 + tare: 50 x 1.10 x 0.80 = 44 lb of refrigerant, plus the 30 lb tare, gives 74 lb.
A 1988 window air conditioner with a running compressor is recovered with a certified machine built in 2015. Which target applies?
- 80 percent of the refrigerant, or a 4 in. Hg vacuum
- 90 percent of the refrigerant, or a 4 in. Hg vacuum
- 100 percent of the refrigerant
- No target, because the appliance was built before 1993
Show answer
Answer: B. The machine was made after November 15, 1993 and the compressor runs, so the target is 90 percent or 4 in. Hg. The 1988 appliance date does not matter.
A technician uses a recovery machine built in 1991 on a dorm refrigerator with a working compressor. What is the minimum recovery?
- 90 percent of the refrigerant
- 95 percent of the refrigerant
- 80 percent of the refrigerant
- No minimum, because the machine predates the rule
Show answer
Answer: C. Recovery equipment made before November 15, 1993 must recover 80 percent of the refrigerant whatever the compressor state, or reach a 4 in. Hg vacuum. The 90 percent target applies only to newer equipment.
Why must a recovery cylinder be filled to no more than 80 percent of its capacity?
- So non-condensables have room to collect
- So the scale reading stays accurate
- Liquid refrigerant expands as it warms, and without vapor space the cylinder can rupture
- So the recovery machine runs cooler
Show answer
Answer: C. Liquid refrigerant expands when its temperature rises. A cylinder filled past 80 percent can become liquid full and burst from hydrostatic pressure.
A 90 lb R-22 chiller air-conditions an office building. For leak repair rules, what category is it and what is its threshold?
- Commercial refrigeration at 20 percent
- Industrial process refrigeration at 30 percent
- Comfort cooling at 10 percent
- Comfort cooling at 35 percent
Show answer
Answer: C. Appliances that control heat or humidity in occupied buildings are comfort cooling, with a 10 percent trigger. Commercial refrigeration is 20 percent and industrial process refrigeration 30 percent; 35 percent is an outdated rule.
Each appliance below holds 300 lb of R-22. Which one has a 30 percent leak rate trigger?
- A supermarket display case rack
- An office building chiller
- A cold storage warehouse system
- A chemical plant process cooling loop
Show answer
Answer: D. The 30 percent trigger applies to industrial process refrigeration, such as chemical plant process cooling. Supermarket racks and cold storage are commercial refrigeration at 20 percent; an office chiller is comfort cooling at 10 percent.
Using post-1993 recovery equipment, what recovery level applies before a major repair on a high-pressure appliance with a full charge of 200 pounds or more?
- 10 inches of Hg vacuum
- 0 inches of Hg
- 0 psig
- 15 inches of Hg vacuum
Show answer
Answer: A. Under Table 1, a high-pressure appliance with a full charge of 200 lb or more must be evacuated to 10 in. Hg vacuum when the recovery equipment was made on or after November 15, 1993.
Before a major repair, to what level must a low-pressure appliance be evacuated?
- 0 psig
- 25 inches Hg vacuum
- 10 inches Hg vacuum
- 25 mm Hg absolute
Show answer
Answer: D. Table 1 sets 25 mm Hg absolute for low-pressure appliances before a major repair or disposal, whatever the recovery equipment date. 0 psig applies only to non-major repairs.
The Type III section has 25 questions. What is the fewest correct answers that passes it?
- 17
- 20
- 21
- 18
Show answer
Answer: D. Each closed-book, proctored section, Type III included, has 25 questions and passes with 18 correct. Open-book, mail-in tests require 21 of 25.
How to study for the EPA 608 exam
Study Core first, then Type 2, then Type 1, then Type 3. Core is the law the other sections apply, so it makes the rest easier to learn. Type 2 has the most rules to memorize. Type 1 is the shortest section. Type 3 goes last because a machine that runs in a vacuum behaves backward from the high-pressure work most technicians know.
How long to study
| Section | With HVAC field experience | New to HVAC |
|---|---|---|
| Core | 4 to 8 hours | 8 to 16 hours |
| Type 1 | 2 to 4 hours | 4 to 8 hours |
| Type 2 | 4 to 8 hours | 6 to 10 hours |
| Type 3 | 6 to 10 hours | 10 to 16 hours |
| All four (Universal) | 16 to 30 hours | 28 to 50 hours |
These hours are our planning estimate, not a measured figure. Book a section once you hold 85% or better on two or three timed practice runs: 18 of 25 passes, and the margin covers a bad day.
Before you set a date, read how hard the EPA 608 test is and the full certification timeline.
Universal study plan
Use the same order for Universal: Core, Type 2, Type 1, Type 3. The exam puts all four sections in one sitting of 100 questions and grades each section on its own, so one weak section does not cost you the other three.
One sitting or several
One sitting is usually the cheaper route. ESCO Institute charges $85 for its online proctored Universal exam (Core and Types 1, 2 and 3, one attempt each), so all four sections cost the same as one Type there. Fees at other organizations differ: see what EPA 608 certification costs. At ESCO, a failed section is retaken on its own and the sections you passed are kept.
What runs out in one sitting is attention, usually in the third block. Treat each 25-question section as its own exam, and rehearse a full 100-question run at least twice before the day.
7-day Universal schedule
| Day | Section | Study | Practice target |
|---|---|---|---|
| 1 | Core | Venting ban dates, penalty, exemptions, refrigerant families | An untimed Core test, to find your gaps |
| 2 | Core | Recovery order, cylinders, reclaim vs recycling, equipment certification | 20 of 25 on a timed Core test |
| 3 | Type 2 | Leak-rate triggers, the repair clock, verification tests | An untimed Type 2 test |
| 4 | Type 2 | Evacuation levels by pressure class, the 0 psig cases | 20 of 25 on a timed Type 2 test |
| 5 | Type 1 | Small appliance definition, 90%, 80% or 4 in. Hg, system-dependent recovery | 20 of 25 on a timed Type 1 test |
| 6 | Type 3 | 25 mm Hg absolute, purge units, leak testing, water in the system | An untimed Type 3 test |
| 7 | Type 3 and review | Rupture disc, R-123, the cheat sheet's wrong-answer column | 20 of 25 on a timed Type 3 test, then one full 100-question run |
Technicians with field experience can often do Type 2 in one day. If seven days is too fast, keep the order and stretch each block.
EPA 608 study guide FAQ
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