EPA 609 Practice Test: 30 Free Questions With Answers (2026)

Quick answer: The real EPA Section 609 test is 25 multiple-choice questions, open book, and you need 84% (21 correct) to pass. It costs about $20–30 online from an EPA-approved program such as MACS, ESCO or Mainstream Engineering, and the certification never expires. The free practice test below uses the same format, with 30 questions and an explanation for every answer.

EPA 609 exam at a glance

Questions: 25 multiple choice (this practice test: 30)
Pass mark: 84% — 21 of 25 correct
Format: open book; you may use the program’s study manual
Cost: roughly $20–30 for the first attempt; retakes are cheaper or free depending on the program
Who needs it: anyone paid to service motor-vehicle air conditioning (MVAC), including HFC-134a and HFO-1234yf systems
Expiry: none — Section 609 certification is for life

How to use this practice test

Click an answer and you get instant feedback plus a short explanation of the rule behind it. Your running score stays pinned at the top. Finish all 30 and you’ll see whether you’d have cleared the 84% line. The questions are grouped the way the real test is weighted: ozone science, regulations and certification, refrigerant chemistry, recovery and recycling equipment, and service procedures.

These are original questions written from EPA’s Section 609 rules and the SAE standards the test is based on. They are not copied from any program’s exam. Before test day, read your chosen program’s current manual, because the real test is open book and a few figures change over time.

Ozone and the environment

1. The ozone layer protects the Earth by absorbing most of the sun’s:

2. About what share of the atmosphere’s ozone is found in the stratosphere?

3. A single chlorine atom released from a CFC molecule can destroy approximately how many ozone molecules?

4. Which refrigerant is assigned an ozone depletion potential (ODP) of 1.0 as the reference point?

5. What is the main environmental concern with HFC-134a?

Regulations and certification

6. Under Section 609 of the Clean Air Act, who must be trained and certified?

7. Since what date has it been illegal to vent substitute refrigerants such as HFC-134a while servicing an MVAC?

8. Since January 1, 1996, it has been illegal to:

9. Since January 1, 2018, who may buy HFC-134a in containers of 2 pounds or more?

10. The sale of HFC-134a in small cans of less than two pounds is:

11. CFC-12 in containers smaller than 20 pounds may only be sold to:

12. A service shop that buys approved recovery equipment must:

13. How long must a shop keep proof that each person using its recovery equipment is Section 609 certified?

14. A technician who services the refrigerant loop of a refrigerated trailer or the HCFC-22 air conditioning on a bus must hold:

15. Under the Clean Air Act, a person who supplies information leading to a penalty against a technician who knowingly vents refrigerant may receive an award of up to:

Refrigerants, oils and system chemistry

16. Air (a non-condensable gas) trapped in an MVAC system will cause:

17. When CFC-12 or HFC-134a contacts an open flame or a very hot surface, it can break down into:

18. Which oil is normally used with HFC-134a in a factory-filled system?

19. HFO-1234yf is classified as which ASHRAE safety group?

20. If the static pressure of an idle system is lower than the saturation pressure of its refrigerant at the ambient temperature, the system:

Recovery, recycling and equipment

21. Recycling equipment manufactured to SAE standards is capable of cleaning refrigerant to a level that is:

22. Which SAE standard covers recover/recycle/recharge machines for HFC-134a?

23. When servicing a vehicle charged with HFC-134a, you should:

24. Before charging a system that has been opened for service, you should:

25. Moisture in recycled CFC-12 that will be returned to an MVAC system must not exceed:

26. After recovery, the system pressure rises again within a few minutes. This indicates:

27. A refillable recovery cylinder should never be filled beyond:

Service procedures and safety

28. When retrofitting a CFC-12 system to HFC-134a, you must:

29. Before an MVAC system or its vehicle is scrapped, the refrigerant must be:

30. Does Section 609 certification expire?

Answer key with explanations

Use this as a study sheet if you prefer to read straight through, or to print before an open-book test.

Open the full answer key (30 answers)

1. A — Ultraviolet (UV-B) radiation. Stratospheric ozone absorbs most harmful UV-B. Increased UV-B exposure is linked to skin cancer, cataracts, immune-system damage and crop and plankton loss.
2. A — 90%. Roughly 90% of ozone sits in the stratosphere, 10 to 30 miles up. Ozone at ground level is a pollutant; ozone in the stratosphere is protective.
3. D — 100,000. Chlorine acts as a catalyst: it breaks apart an ozone molecule, is released again and repeats the cycle, destroying up to 100,000 ozone molecules before it leaves the stratosphere.
4. B — CFC-11. CFC-11 is the ODP reference at 1.0 (CFC-12 is also about 1.0). HFC-134a, HFO-1234yf and CO2 contain no chlorine and have an ODP of zero.
5. C — It has a high global warming potential (GWP). HFC-134a contains no chlorine, so its ODP is zero, but its GWP is roughly 1,400 times that of CO2. That is why newer vehicles use HFO-1234yf, whose GWP is below 1.
6. A — Anyone who services an MVAC system for payment or barter. EPA’s wording is ‘for consideration’, meaning payment or bartering. A hobbyist working on their own car is not covered, but anyone paid to service an MVAC must be certified by an EPA-approved program.
7. B — November 15, 1995. Venting CFCs and HCFCs became illegal on July 1, 1992. The ban was extended to substitutes such as HFC-134a on November 15, 1995. Among SNAP-approved MVAC refrigerants, only CO2 (R-744) is exempt from the venting ban.
8. B — Manufacture or import CFC-12 in the United States. Production and import of CFCs ended for the US on January 1, 1996 under the Montreal Protocol schedule. Servicing and retrofitting existing CFC-12 systems with recovered or recycled refrigerant remains legal.
9. C — Only Section 608 or 609 certified technicians. EPA extended the refrigerant sales restriction to non-exempt HFC substitutes on January 1, 2018. Containers of 2 lb or more may only be sold to technicians certified under Section 608 or 609, or to a buyer who gives a written statement that the refrigerant is for resale.
10. D — Allowed to anyone, provided the can has a self-sealing valve. Small cans (under 2 lb) are exempt from the certification requirement when they are fitted with a self-sealing valve, which prevents the remaining charge from leaking after the can is disconnected. Older cans without the valve may not be sold to uncertified buyers.
11. C — Section 609 certified technicians. Small containers of CFC-12 are restricted to Section 609 certified technicians, and the seller must verify the certification. Sellers must also post a sign stating the purchaser certification requirement.
12. B — Certify once to its EPA Regional Office that it owns approved equipment and that its technicians are certified. The shop submits a one-time signed statement listing the purchaser, the shop’s name and address, and the equipment’s brand, model, year and serial number. A shop that already certified CFC-12 or HFC-134a equipment does not have to re-certify when it buys HFO-1234yf equipment.
13. A — 3 years. Records of technician certification, and of where recovered refrigerant is sent, must be kept on site for three years. Retailers keep resale statements for the same period.
14. B — Section 608 certification. Section 609 covers passenger-compartment comfort cooling in motor vehicles. Refrigerated transport units and HCFC-22 bus air conditioning fall under Section 608. MVAC-like appliances such as farm and construction equipment can be serviced with either Section 609 or Section 608 Type II certification.
15. C — $10,000. Section 113(f) of the Clean Air Act allows EPA to pay awards of up to $10,000 for information leading to a criminal conviction or civil penalty. Fines for violations can run to tens of thousands of dollars per day.
16. B — Higher than normal high-side (discharge) pressure and poor cooling. Air does not condense in the condenser, so it takes up space and raises discharge pressure while cooling performance drops. This is why a system that has been opened must be evacuated before it is recharged.
17. A — Hydrochloric and hydrofluoric acid, and possibly phosgene gas. Decomposition products are toxic and corrosive. Never smoke near refrigerant, never use a flame-type leak detector, and keep refrigerant away from welding and brazing.
18. A — PAG (polyalkylene glycol) oil. Mineral oil does not mix with HFC-134a, so most OEM systems use PAG oil. Ester (POE) oil is often used in CFC-12-to-HFC-134a retrofits because it is more tolerant of leftover mineral oil. PAG oil is strongly hygroscopic, so keep containers sealed.
19. C — A2L (mildly flammable, low toxicity). HFO-1234yf is mildly flammable. It needs equipment built to SAE J2843, which includes a refrigerant identifier and safeguards against ignition, and work areas must be ventilated.
20. A — Contains no liquid refrigerant and is low on charge. With the system off, a correctly charged system settles at the refrigerant’s saturation pressure for the ambient temperature. A lower reading means there is no liquid left, so the charge has leaked out. Find and repair the leak before recharging.
21. D — Acceptable for reuse in motor vehicle air conditioning systems. Recycled refrigerant meets SAE purity standards (J1991 for CFC-12, J2099 for HFC-134a) and may be reused in MVAC systems. It is not the same as reclaimed refrigerant, which is processed off site to AHRI Standard 700 and tested to match new refrigerant.
22. B — J2788. J2788 (which replaced J2210) applies to HFC-134a recover/recycle/recharge equipment and requires it to recover at least 95% of the charge. J1990 covers CFC-12, J2843 covers HFO-1234yf, and J2851 covers recovery-only machines for HFC-134a or HFO-1234yf.
23. B — Use equipment dedicated to HFC-134a and identify the refrigerant before recovery. Refrigerants must never be mixed. Each refrigerant has its own service fittings and dedicated recovery equipment. A refrigerant identifier before recovery protects your machine and your stored refrigerant from contamination.
24. C — Evacuate it with a vacuum pump to remove air and moisture. Evacuating to a deep vacuum removes air and boils off moisture. Moisture reacts with refrigerant and oil to form acids that corrode the system and can freeze at the expansion device. Shop air introduces both air and moisture.
25. C — 15 parts per million by weight. SAE J1991 sets purity limits for recycled CFC-12: 15 ppm moisture, 4,000 ppm oil and 330 ppm non-condensable gases. For HFC-134a, SAE J2099 allows 50 ppm moisture, 500 ppm oil and 150 ppm non-condensables.
26. D — Refrigerant is still trapped in the oil or the system is leaking air in, so recovery should continue. A pressure rise after recovery means refrigerant is still boiling out of the compressor oil or components. Wait, then recover again until the system holds a stable vacuum.
27. A — 80% of its capacity. Liquid refrigerant expands as it warms. Leaving 20% headroom prevents hydrostatic pressure from rupturing the cylinder. Never heat a cylinder above 125 F, and never refill a disposable cylinder.
28. A — Fit unique HFC-134a service fittings and apply a retrofit label. Each refrigerant needs its own unique fittings (SAE J639) so the wrong equipment cannot be connected. The retrofit label records the new refrigerant and oil, the charge amount and the date. Remove as much mineral oil as practical and recover all CFC-12 first.
29. D — Recovered by the last person in the disposal chain, or confirmed already recovered. EPA’s safe-disposal rule puts responsibility on the final person who handles the vehicle, such as a salvage yard. Refrigerant must be recovered before disposal. Disposable cylinders must likewise be evacuated to a vacuum before they are discarded.
30. D — No, it is valid for life. Section 609 certification does not expire and does not require renewal. If you lose your card, contact the program that certified you (MACS, ESCO, Mainstream Engineering and others) for a replacement; most charge a small fee.

Questions people ask about the EPA 609 test

The sale of HFC-134a in containers less than two pounds is restricted to whom?

No one, provided the can has a self-sealing valve. Since January 1, 2018, HFC-134a in containers of 2 pounds or more may only be sold to Section 608 or 609 certified technicians (or to buyers who sign a resale statement). Small cans under 2 pounds are exempt when fitted with a self-sealing valve. Older-style cans without the valve may not be sold to uncertified buyers.

Recycling equipment manufactured to SAE standards is capable of what?

Cleaning recovered refrigerant to a purity acceptable for reuse in motor-vehicle air conditioning systems: SAE J1991 for CFC-12 and SAE J2099 for HFC-134a. Recycled refrigerant is not the same as reclaimed refrigerant, which is processed off site to AHRI Standard 700.

When servicing a vehicle charged with HFC-134a, you should do what?

Identify the refrigerant first, then use recovery equipment dedicated to HFC-134a. Never connect CFC-12 or HFO-1234yf equipment to an HFC-134a system, and never top one refrigerant up with another.

Before charging a system that has been opened for service, what must you do?

Evacuate it with a vacuum pump. A deep vacuum removes air (a non-condensable that raises head pressure) and boils off moisture that would otherwise form acids inside the system.

How much does the EPA 609 test cost?

Online tests from EPA-approved programs run about $20 to $30 for the first attempt. MACS charges $29, Mainstream Engineering’s EPATest.com charges $21.95 with $6.95 retakes, and ESCO’s Section 609 test is around $20. Study manuals are usually free to download.

Does EPA 609 certification expire?

No. Section 609 certification is valid for life and needs no renewal. If you lose your card, contact the program that certified you for a replacement; MACS charges $17.

Is 609 the same as EPA 608?

No. Section 609 covers motor-vehicle air conditioning. Section 608 covers stationary equipment and refrigerated transport units. See our EPA 608 vs. 609 comparison and the EPA 608 practice test if you need both.

Where to take the real EPA 609 test

Any program on EPA’s approved list is valid nationwide. The three most used online options:

MACS (Mobile Air Climate Systems Association) — $29, English or Spanish, free study manual and a 10-question practice exam.
Mainstream Engineering (EPATest.com) — $21.95, unlimited $6.95 retakes, immediate result.
ESCO Institute — about $20 online, also offers a mail-in packet.

Pick one, download its manual, run through this practice test twice, and you should be ready.