EPA 608 Type III is the federal certification for maintaining, servicing, repairing, and disposing of low-pressure appliances — EPA's published examples are chillers running R-11, R-123, R-113, or R-245fa.
In practice, it is the chiller cert: chiller and refrigeration techs, and the building engineers who run central plants, need Type III or Universal to open those circuits.
The Type III exam adds at least 25 questions on top of Core, closed-book and proctored, with a 70 percent pass mark.
What is low-pressure equipment?
Under 40 CFR 82.161, Type III certification covers anyone who maintains, services, repairs, or disposes of low-pressure appliances.
EPA's published examples of the class are chillers running R-11, R-123, R-113, or R-245fa — a list of refrigerants, not equipment sizes.
That is the key to the type: EPA draws its pressure classes by refrigerant saturation pressure — the published high-pressure definition is 170 to 355 psia liquid saturation pressure at 104 °F — and the pages we read don't print the low-pressure line itself.
What the low-pressure definition does give is its examples, and those are chillers — so the type lines up with chiller work.
Where it sits on the ladder: Type I covers small appliances — factory-sealed units with 5 pounds or less of refrigerant — and Type II covers the three classes above low-pressure: medium, high, and very high, with small appliances, MVACs, and MVAC-like appliances carved out.
Type III is the opposite end of the pressure scale from Type II's classes.
The full side-by-side is in our guide to epa 608 types.
The class you certify for also decides the numbers you memorize.
Recovering refrigerant from a low-pressure appliance means evacuating it to 25 mm Hg absolute — a different scale from the inch-of-mercury evacuation targets for the higher-pressure classes, and a distinction worth drilling.
Which jobs need Type III certification?
The rule reaches anyone who could reasonably be expected to violate the integrity of a refrigerant circuit while maintaining, servicing, repairing, or disposing of an appliance.
For Type III, that means low-pressure appliances — chillers, the equipment EPA's own examples name.
The certification follows the equipment, not the job title: whether the posting says chiller technician, refrigeration tech, or building engineer, opening a low-pressure circuit calls for Type III or Universal.
New to the trade?
Apprentices are exempt from 608 certification only while they are 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 that exemption — but the first time you open a low-pressure circuit on your own, Type III stops being optional.
The rule bites in a practical place: refrigerant purchasing.
Only EPA-certified technicians may buy ozone-depleting or substitute refrigerants such as HFCs, with limited exceptions — an employer can buy if it gives the wholesaler written evidence that it employs at least one certified technician.
The EPA 608 certification overview covers who exactly the rule reaches and how the exam process runs.
Already hold Type II?
Universal certification covers all three types, and it can be taken in one 100-question sitting or built up by combining passing scores on separate type tests — so sitting the Type III exam adds the low-pressure class to your card.
Certified and looking?
Open HVAC technician jobs are on our board.
What topics are tested?
The shape first.
Every 608 exam pairs at least 25 questions from the core group with at least 25 from each relevant technical group, so the Type III test combines both groups: at least 25 Core questions and at least 25 Type III questions.
Type III is a closed-book test, proctored in a secure environment, and the passing score is 70 percent.
EPA states the bar as a percentage, not as a count of missed questions.
EPA publishes the Type III topic list, and its signature items are specific to low-pressure equipment:
- Heat the oil to 130 °F before removing it — EPA's stated reason is to minimize refrigerant release
- Introduce vapor before liquid when recharging — to avoid freezing water in the tubes
- ASHRAE 15 equipment-room refrigerant sensors — required for R-123
Evacuation sits on the Core topic list too — recovery and evacuation techniques — and the low-pressure row is the one Type III candidates drill: with recovery equipment manufactured on or after November 15, 1993, a low-pressure appliance must be evacuated to 25 mm Hg absolute.
Equipment made before that date carries the same 25 mm Hg absolute target for low-pressure appliances.
Alongside the exam topics sit the leak-repair rules of the same subpart.
Under 40 CFR 82.157 — which, as of April 10, 2020, applies only to appliances with a full charge of 50 or more pounds of class I or class II refrigerant, the ozone-depleting kind — the leak-rate thresholds that trigger a repair are:
- 10 percent for comfort cooling and other appliances
- 20 percent for commercial refrigeration
- 30 percent for industrial process refrigeration
When a covered appliance crosses its threshold, the owner must repair it within 30 days — extended to 120 days when an industrial process shutdown is needed — and a certified technician must perform the leak inspection.
And if a covered appliance — one holding 50 or more pounds of class I or class II refrigerant — leaks 125 percent or more of its full charge in a calendar year, the owner must report it to EPA by March 1 of the following year.
Scope check before you study: do not carry those 82.157 percentages onto HFC equipment.
EPA's 2020 rule removed the 82.157 leak-repair requirements for appliances using only substitute refrigerants such as HFCs, while keeping the certification, sales restriction, evacuation, certified-recovery-equipment, safe-disposal, and reclamation rules for them.
HFC leak repair now lives under the AIM Act's Emissions Reduction and Reclamation rule, which re-imposed leak repair from January 1, 2026 on appliances with 15 or more pounds of HFC or substitute refrigerant with a GWP above 53 — excluding residential and light-commercial air-conditioning and heat-pump appliances.
The honest limit: the question bank itself is not public.
EPA releases it only to approved certifying programs, and the public topics page we read still frames the leak-repair questions around the 50-pound threshold and ozone-depleting equipment — it does not mention A2L refrigerants or the AIM Act, and our research found no public confirmation that the bank has been rewritten.
Study the published topics; do not assume your form does or does not include newer material.
Two leak-repair rules — check which one applies
Type III practice questions
Five Type III-style questions, drawn from the Section 608 rules above — a mini epa 608 type 3 practice exam.
Answer each before you read the explanation.
Question 1. EPA's own definition classifies R-410A as which pressure class?
- A. Very-high-pressure
- B. High-pressure
- C. Medium-pressure
- D. Low-pressure
Answer: B.
EPA's definition puts R-410A — with R-22, R-407A, R-407C, and R-502 — in the high-pressure class: 170 to 355 psia liquid saturation pressure at 104 °F.
Prep materials often say very-high-pressure; EPA's own definition says high-pressure — and high-pressure appliances are Type II territory, not Type III.
Question 2. Your recovery unit was manufactured on or after November 15, 1993. To what level must you evacuate a low-pressure appliance?
- A. 0 in. Hg
- B. 10 in. Hg
- C. 15 in. Hg
- D. 25 mm Hg absolute
Answer: D.
Low-pressure appliances evacuate to 25 mm Hg absolute — and for this class, the same target holds for equipment made before November 1993.
The inch-of-mercury answers belong to the higher-pressure classes — watch the change of scale.
Question 3. Which safety provision does EPA's Type III topic list name for R-123 equipment rooms?
- A. ASHRAE 15 equipment-room refrigerant sensors
- B. Quarterly cylinder pressure tests
- C. A mechanical-room ventilation permit
- D. None — R-123 is exempt from sensor requirements
Answer: A.
EPA's Type III topic list names ASHRAE 15 equipment-room refrigerant sensors, required for R-123 — the machine-room safety item on the low-pressure topic list.
Question 4. Why does EPA's Type III topic list say to heat the oil before removing it from a low-pressure appliance?
- A. To thin the oil so it drains faster
- B. To minimize refrigerant release
- C. To dry moisture out of the oil
- D. To keep the compressor bearings warm
Answer: B.
To minimize refrigerant release — and the list's number is 130 °F: heat the oil to 130 °F before removing it.
Question 5. An appliance holding 50 pounds or more of ozone-depleting refrigerant leaks 125 percent of its full charge in a calendar year. By when must the owner report it to EPA?
- A. Within 30 days
- B. Within 120 days
- C. By March 1 of the following year
- D. No report is required
Answer: C.
The chronic-leaker rule: 125 percent or more of full charge in a calendar year means a report to EPA by March 1 of the following year.
Watch the 30- and 120-day distractors — those windows belong to the repair rule, not the report.
These five drill the rules above; a full free set covering Core, Type I, Type II, and Type III is on our epa 608 practice test page.
When you are passing those consistently, book the proctored exam through an EPA-approved certifying organization.
This page is career information, not legal advice. Confirm the current Section 608 requirements with EPA before you act on them.