EPA 608 Refrigerant Cert Prep
Study the Core section of the EPA Section 608 exam, covering the law, refrigerant classes, venting, the three Rs, cylinders, leak repair rules and records.
Table of contents
Every Section 608 candidate must pass Core, no matter which equipment type they want. Core tests the law and the basics that apply to all refrigerant work: who needs a card, what you may never release, how refrigerant is stored, and which leaks must be repaired. The exam writes its questions from federal rules, so the numbers below matter. Rules change, so check the current EPA Section 608 pages before you test.
What You Will Be Able to Do
- State who needs Section 608 certification and which type covers which equipment.
- Tell legal releases from illegal venting.
- Define recovery, recycling and reclamation.
- Apply the cylinder rules for fill level, testing and labeling.
- Explain leak repair thresholds, deadlines and records for ozone-depleting and HFC refrigerants.
The Laws Behind the Exam
Clean Air Act Section 608 is the base law. EPA's rules under it are in 40 CFR Part 82, Subpart F. They cover venting, technician certification, recovery equipment, sales and disposal.
The AIM Act of 2020 gave EPA power over HFCs. Its rules in 40 CFR Part 84 cover the HFC phasedown, the move to lower-GWP equipment, and, since January 1, 2026, leak repair and recovery for HFCs and their substitutes.
Penalties under the Clean Air Act can pass $100,000 per day for each violation. The law also lets EPA pay rewards for tips that lead to a penalty or conviction.
Who Needs Certification
You need a card if you do work that could reasonably release refrigerant from a stationary appliance. That includes attaching gauges, adding or removing refrigerant, and opening the circuit.
Three exceptions come up often:
- Motor vehicle AC falls under Section 609, not 608.
- Apprentices do not need a card while a certified technician closely and continually supervises them.
- Disposal-only work on small appliances, such as a person recovering refrigerant at a scrap yard, does not need a card.
Keep a copy of your certificate at your place of business. The card does not expire under the current rules.
The Certification Types
| Type | Equipment covered | Common refrigerants |
|---|---|---|
| Type I | Small appliances, factory sealed with 5 lb or less | R-134a, R-22, R-600a |
| Type II | High, medium and very-high-pressure appliances | R-410A, R-22, R-134a, R-454B |
| Type III | Low-pressure appliances | R-11, R-123 |
| Universal | All of the above | All of the above |
EPA defines these classes by the refrigerant's saturation pressure at 104°F. High-pressure is 170 to 355 psia. Medium-pressure is 45 to 170 psia. Low-pressure is below 45 psia. Very-high-pressure means above 355 psia, or a critical temperature below 104°F. Older study material may show different numbers, so learn these.
Refrigerant Classes and Phaseouts
Ozone depletion potential (ODP) compares a chemical's harm to the ozone layer with R-11, which is set at 1.0. Global warming potential (GWP) compares how much heat a gas traps with carbon dioxide, which is set at 1.
| Class | Contains | Examples | Status |
|---|---|---|---|
| CFC | Chlorine | R-11, R-12 | U.S. production ended in 1995 |
| HCFC | Chlorine, less of it | R-22, R-123 | No new R-22 made or imported since January 1, 2020 |
| HFC | No chlorine | R-410A, R-134a, R-32 | Phasing down 85% by 2036 |
| HFO | No chlorine, very low GWP | R-1234yf | Used more each year |
Chlorine is what damages ozone. HFCs have zero ODP but can have high GWP, which is why the AIM Act targets them. Remaining R-22 supply comes from stock and from recovered and reclaimed refrigerant.
Venting
Knowingly releasing refrigerant during service, repair or disposal has been illegal for ozone-depleting refrigerants since July 1, 1992, and for substitutes such as HFCs since November 15, 1995.
The narrow exception is a de minimis release, a tiny amount lost during good-faith use of recovery equipment that meets EPA rules. A small release when you connect or disconnect hoses during proper work is one example. Leaks during normal operation and mechanical purging are not treated as venting, although leak repair rules may still apply.
EPA has exempted a short list of substitutes from the ban in certain uses, such as carbon dioxide, nitrogen and water. Ammonia is exempt in commercial, industrial and absorption systems. Do not assume a refrigerant is exempt. Check the current list.
You may not add nitrogen to a charged system and blow it out to skip recovery. That is venting.
The Three Rs
| Word | What it means | Who may use it afterward |
|---|---|---|
| Recover | Remove refrigerant in any condition into an external container, with no testing | The same owner's equipment |
| Recycle | Clean it for reuse, using oil separation and filter-driers | The same owner's equipment |
| Reclaim | Reprocess it to AHRI 700 purity at a certified reclaimer | Any owner, because it may be resold |
A memory aid: recover means remove, recycle means reuse, reclaim means resell. Only reclaimed refrigerant can be sold to a new owner. AHRI 700 is the purity standard, and AHRI 740 is the performance standard for recovery equipment. EPA-certified recovery equipment is required.
Cylinders
- Fill limit: 80% of the cylinder's rated capacity, by weight. Fill limits are figured so liquid has room to expand as the cylinder warms, up to 130°F. Use a scale.
- Recovery cylinders: gray body with a yellow top. They must be DOT-approved and rated for the refrigerant.
- Hydrostatic retest: every 5 years. The date is stamped on the cylinder.
- New refrigerant: AHRI Guideline N now calls for a uniform gray color on new containers, so read the label. Older colors, such as rose for R-410A, are being phased out. A red band marks a flammable refrigerant.
- Disposable cylinders: never use one for recovery and never refill one. Starting January 1, 2028, used disposable cylinders must go to a reclaimer or be evacuated to a set level by a certified technician.
- Labels: mark the refrigerant type and keep each cylinder to one refrigerant. Mixed refrigerant may not be reclaimable.
Worked example: an empty cylinder is set on a scale and zeroed. Its label says it may hold up to 40 lb of the refrigerant you are recovering. You stop at 40 lb, even if the machine could keep going.
Evacuation Numbers
After a repair, system evacuation commonly targets 500 microns, confirmed by a decay test with the pump isolated. This is an industry and manufacturer target. Do not confuse it with EPA's required recovery levels, which are in inches of mercury and vary by appliance. The required levels appear on the Type I, II and III sections.
Leak Repair Rules
Which rule applies depends on the refrigerant in the appliance. The leak rate limits are the same in both.
| Item | Ozone-depleting (Part 82) | HFC and substitutes (Part 84) |
|---|---|---|
| Applies at | 50 lb or more | 15 lb or more, GWP above 53 |
| Comfort cooling | 10% a year | 10% a year |
| Commercial refrigeration | 20% a year | 20% a year |
| Industrial process refrigeration | 30% a year | 30% a year |
Commercial refrigeration here means retail food and cold storage systems. The HFC program leaves out residential and light commercial AC and heat pump appliances.
When a leak passes the limit:
- Repair it within 30 days. Some industrial process shutdowns get 120 days.
- Do an initial verification test at the time of the repair.
- Do a follow-up verification test within 10 days.
- If you cannot repair it, make a retrofit or retirement plan within 30 days and finish within 1 year.
Larger systems also have regular leak inspection duties, and commercial and industrial systems with 1,500 lb or more need automatic leak detection under Part 84. An owner must report to EPA if a system loses 125% or more of its charge in a year.
Worked example: an owner adds 5 lb to a 60 lb comfort cooling system, 73 days after the last addition. Annual leak rate = (5 / 60) x (365 / 73) x 100 = about 41.7%. That is above 10%, so repair rules apply.
Records
The owner or operator keeps these records for at least 3 years, with your invoice supporting them:
- Full charge and how it was worked out.
- Each refrigerant addition, with the date, amount and reason.
- Leak repair details, such as the date found, the leak rate, the repair made, the verification test and the technician's name.
- Disposal records for appliances over 5 lb and under 50 lb.
Sellers keep invoices for 3 years as well.
Sales and Disposal
Refrigerant may be sold only to Section 608 holders or to employers with written proof that a certified person works for them. Section 609 holders may buy refrigerant for motor vehicle AC only. The exception is small cans of 2 lb or less with a self-sealing valve, which are for do-it-yourself vehicle repair.
The last person in the disposal chain, such as a scrap yard, must make sure refrigerant was removed. That person keeps a signed statement saying who did it and when.
Safety Questions
Expect a few questions on the basics:
- Refrigerant in a closed space displaces oxygen.
- Liquid refrigerant causes frostbite, so wear eye protection and suitable gloves.
- Never braze on a system holding refrigerant. Heat breaks it down into toxic gases.
- Use dry nitrogen with a regulator for pressure tests, never oxygen or compressed air.
How the Exam Works
| Item | Detail |
|---|---|
| Sections | Core, Type I, Type II, Type III |
| Questions | 25 in each section |
| Passing score | 70%, which means 18 of 25 in practice |
| Format | Closed book, with a proctor |
| Mail-in Type I | 84%, or 21 of 25, and it does not count toward Universal |
| Universal | Core and all three types, 100 questions |
You must pass Core and at least one type to hold that type. Approved programs must issue your card within 30 days.
Common Mistakes
| Mistake | What it costs |
|---|---|
| Studying old pressure numbers | Wrong answers on scope questions |
| Mixing up 500 microns with EPA recovery levels | Wrong answers on evacuation questions |
| Memorizing 50 lb as the only leak threshold | Wrong answers on HFC questions |
| Calling recycled refrigerant reclaimed | A failed definition question, and an illegal sale if you do it on the job |
Check Your Understanding
A helper connects gauges to a rooftop unit while a certified tech is on the other side of town. Is that allowed? No. The apprentice exception needs close and continual supervision.
You see a 90 lb R-410A comfort cooling system leaking 15% a year. Does the leak repair rule apply? Yes. It is above 15 lb, its GWP is above 53, it is not residential or light commercial, and the leak rate is over 10%.
A shop owner wants to sell recovered R-22 from one customer's system to another customer. Is that legal? Not unless it was reclaimed to AHRI 700 purity by a certified reclaimer.
A recovery cylinder's hydrostatic date is 6 years old. May you use it? No. It is past its 5-year retest date.
Key Takeaways
- Core covers the law and basics, and every candidate must pass it.
- Venting is illegal, except de minimis releases during good-faith recovery.
- Type II covers high, medium and very-high-pressure appliances. Type III covers those below 45 psia.
- Only reclaimed refrigerant at AHRI 700 purity can be sold to a new owner.
- Fill cylinders to 80% by weight, and retest them every 5 years.
- Leak limits are 10%, 20% and 30%, at 50 lb for ozone-depleting refrigerants and 15 lb for HFCs with GWP above 53.