The EPA 608 Core section is the shared, mandatory block of every 608 exam: at least 25 questions on ozone depletion, the Clean Air Act and Montreal Protocol, the venting prohibition, the sales restriction, the three Rs of refrigerant, recovery and evacuation technique, safety, and shipping labels.
Pass it and a type section at 70 percent on the closed-book tests and the certification is yours.
Here is exactly what the Core tests, plus an EPA 608 Core practice exam.
What does the Core section test?
EPA publishes the topic list for the Core section, and it reads like the syllabus for the whole regulation: ozone depletion, the Clean Air Act and the Montreal Protocol, the venting prohibition, the sales restriction, the "three Rs" of refrigerant — recover, recycle, reclaim — recovery and evacuation techniques, safety, and shipping labels.
Study against that published list rather than a prep site's summary of it.
The Core never travels alone.
Each EPA 608 test must include at least 25 questions from the core group plus at least 25 questions from each technical group you sit.
A single-type exam is therefore at least 50 questions, and the Universal test is 100, 25 of them Core.
Format matters as much as content.
The closed-book tests are proctored in a secure environment by an EPA-approved certifying program, and the passing bar is 70 percent.
One booking trap to know before test day: a Core taken open-book cannot be used to earn Universal certification.
If Universal is the goal, the Core must be proctored.
Where the Core sits in the credential itself — who legally needs it and what each type adds — our EPA 608 certification guide covers the whole credential, and our guide to EPA 608 types matches each type section to the equipment it covers.
Why must everyone pass Core?
Because the rule attaches to the work, not the job title.
Under 40 CFR 82.161, EPA requires certification for any person who could reasonably be expected to violate the integrity of the refrigerant circuit while maintaining, servicing, repairing, or disposing of appliances containing CFC/HCFC or non-exempt substitute refrigerants such as HFCs.
If the circuit can be opened, the requirement follows the circuit — whoever holds the wrench.
Money is the second reason.
With limited exceptions, only EPA-certified technicians may buy ozone-depleting or substitute refrigerants such as HFCs — Section 608 for stationary refrigerant, Section 609 for vehicle air conditioning.
An employer can buy for its crews, but only by giving the wholesaler written evidence that it employs at least one certified technician.
Apprentices get a narrow carve-out: the exemption applies only while the apprentice is closely and continually supervised by a certified technician, and the supervising technician and the apprentice share responsibility for compliance.
The rule sets no time limit on the exemption — a "2-year apprentice limit" you may have read about is not part of 40 CFR 82.161(a)(2).
And the rule has teeth.
EPA may require a technician to demonstrate at their place of business that they can properly recover and recycle refrigerant, and may suspend or revoke a certificate for failing to do so or for breaking the Subpart F rules.
The penalty side scales to match: under EPA's inflation-adjustment table, the maximum civil penalty under Clean Air Act §113(b) is up to $124,426 per violation for penalties assessed on or after January 8, 2025.
Which rules and numbers must you memorize?
Core rewards memorization: EPA's published topic list is full of the regulation's own anchors — a law and a treaty, a list of three, a gas to use and a fill level never to exceed.
Learn them cold and the recall questions take care of themselves.
- Recovery cylinders: never fill one more than 80 percent full — EPA names it right on the Core safety topics
- Leak testing: pressurize with nitrogen, never oxygen
- The three Rs: recover, recycle, reclaim
- Who may buy refrigerant: EPA-certified technicians, with the employer exception — written evidence of at least one certified technician
- The venting prohibition, plus the Clean Air Act and Montreal Protocol pairing
- Shipping labels for refrigerant — a named Core topic
- The exam's own numbers: at least 25 Core questions, 70 percent to pass closed-book
One absence to know about: EPA's published test-topics page does not mention A2L refrigerants or the AIM Act, and our research found no public confirmation that the question bank has been rewritten for them.
Study the published Core topic list rather than prep-site claims about "new" content.
And treat any course sold as "EPA-approved" as a red flag — EPA does not review or approve study materials of any kind; only the certifying programs that give the test are approved.
These numbers come from EPA's rule — confirm them before your exam
Core practice questions
The eight questions below are original Core practice questions built from EPA's published topic list and the rule itself.
They are not recycled real exam items — our research found no public copy of EPA's question bank, which the rule releases only to approved certifying programs — and nothing here is "EPA-approved", because EPA approves certifying programs, not practice material.
Every answer explanation names the rule behind it, so each miss tells you what to re-read.
Question 1. How many Core questions does every EPA 608 exam include?
- A. It depends on which type you sit
- B. At least 25
- C. At least 50
- D. Exactly 100
Answer: B.
The rule requires every test to include at least 25 questions from the core group, plus at least 25 from each relevant technical group.
A single-type exam therefore runs at least 50 questions; only the Universal test is fixed at 100, 25 of them Core.
Question 2. Under 40 CFR 82.161, EPA's certification requirement attaches to:
- A. Only technicians who hold a state licence
- B. Only employees whose job title includes "technician"
- C. Any person who could reasonably be expected to violate the integrity of the refrigerant circuit while maintaining, servicing, repairing, or disposing of an appliance
- D. Only the person who buys the refrigerant
Answer: C.
The requirement follows the circuit, not the title, and it covers appliances containing CFC/HCFC or non-exempt substitute refrigerants such as HFCs.
Question 3. Which answer correctly lists the "three Rs" EPA's Core topics cover?
- A. Reduce, reuse, recycle
- B. Recover, recycle, reclaim
- C. Recover, repair, replace
- D. Reclaim, remove, retrofit
Answer: B.
EPA's Core topic list names recover, recycle, and reclaim together; all three are named Core topics, so know which is which.
Question 4. An uncertified apprentice is put on a refrigerant circuit. When is that legal?
- A. Never — everyone who touches refrigerant must be certified
- B. Any time, as long as a certified technician is somewhere in the building
- C. Only while the apprentice is closely and continually supervised by a certified technician
- D. For the apprentice's first 2 years only
Answer: C.
The exemption demands close and continual supervision, and the supervising technician and the apprentice share responsibility for compliance.
There is no time limit in the rule — a "2-year apprentice limit" is not part of 40 CFR 82.161(a)(2).
Question 5. Can a Core section taken open-book count toward Universal certification?
- A. Yes, if the score is high enough
- B. Yes, at any approved certifying program
- C. No — the Core must be taken proctored to earn Universal
- D. Only when combined with a mail-in Type I
Answer: C.
EPA states directly that a Core taken open-book cannot be used to earn Universal certification.
If Universal is your target, book the proctored Core from the start — an open-book pass is a dead end for that goal.
Question 6. A shop keeps one 608-certified technician on staff while the rest of the crew is uncertified. How can the shop buy refrigerant for its jobs?
- A. It cannot — every member of the crew must be certified
- B. The employer gives the wholesaler written evidence that it employs at least one certified technician
- C. Only if the certified technician is present at every purchase
- D. Only with written approval from EPA
Answer: B.
The sales restriction lets an employer buy if it gives the wholesaler written evidence that it employs at least one certified technician.
The restriction covers ozone-depleting and substitute refrigerants such as HFCs, with limited exceptions.
Question 7. What is the maximum civil penalty under Clean Air Act §113(b) for breaking the refrigerant rules?
- A. A written warning only
- B. Up to $124,426 per violation
- C. Up to $124,426 per year
- D. There is no federal civil penalty
Answer: B.
Under EPA's inflation-adjustment table, the maximum civil penalty under §113(b) is $124,426 for penalties assessed on or after January 8, 2025 — stated per violation.
The figure comes from an inflation-adjustment table, so it changes as EPA updates it; look it up rather than trusting any memorized number.
Question 8. What score do you need to pass the Core section of a closed-book EPA 608 exam?
- A. 70 percent
- B. 84 percent
- C. 80 percent
- D. 50 percent
Answer: A.
The passing score is 70 percent for the closed-book Type I, Type II, Type III and Universal tests; 84 percent belongs to the mail-in Type I format.
EPA states the bar as a percentage — you may see a certifying organization convert it to a question count, but that rounding is the organization's convention, not EPA's.
Take the eight above closed-book — no notes, no looking things up — and re-read the topic behind every miss.
After you pass, the certifying program must tell you your results and issue a standard wallet-sized card within 30 days of the test — the ceiling the rule sets, not a promise of overnight turnaround — and the card comes from that organization, not from EPA.
If a section beats you anyway, the retake is between you and your certifying organization: EPA does not regulate prices or retake policies, and our research did not confirm individual organizations' rules — ask before you book.
Core, remember, is only the shared part of the exam.
Drill the type sections with our free EPA 608 practice test — and once the card is in your wallet, our HVAC technician jobs board shows which shops are hiring certified techs.
This page is career information, not legal advice. Confirm current exam requirements with EPA's Section 608 program before you act on them.