The EPA 608 exam tests specific numbers more than any other HVAC certification. Dates must be exact. Penalty amounts must be current. Thresholds must be assigned to the right equipment category, not just memorized in isolation. This cheat sheet organizes every testable number by section, with the most commonly confused values flagged.
How to use this cheat sheet: study one section's numbers completely before moving to the next. Cover the value column and test yourself from the label. When you can reproduce every number in the table from memory, you are ready to attempt practice questions.
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EPA 608 Core: dates, penalties, and exemptions
| Topic | Value | Common wrong answer |
|---|---|---|
| CFC and HCFC venting prohibition effective | July 1, 1992 | November 15, 1995 (wrong, that is the HFC date) |
| HFC venting prohibition added | November 15, 1995 | July 1, 1992 (wrong, that is the CFC and HCFC date) |
| Current civil penalty | Exceeds $44,539 per day per violation | $37,500 (outdated) |
| De minimis exemption | 0.1 ounce or less, no recovery required | 1 ounce, 0.5 lb |
| Passing score (proctored) | 18 of 25 (72%) | 70%, 75% |
| Type I open book threshold | 21 of 25 (84%) | 18 of 25 (same as proctored) |
Most missed Core number: the civil penalty
The $37,500 figure appeared in older study guides and still shows up on competitors' sites. The current inflation adjusted civil penalty exceeds $44,539 per day per violation under 40 CFR Part 82.169. Study guides that cite $37,500 will produce a wrong answer on current exams.
Most missed Core date distinction: July 1, 1992 covers CFCs and HCFCs. HFCs were added November 15, 1995. Questions that present 1992 as the HFC ban date are testing whether you know the distinction.
EPA 608 Type I: recovery thresholds and small appliance rules
| Topic | Value | Common wrong answer |
|---|---|---|
| Manufactured charge limit for Type I | 5 lbs or less | 10 lbs, 50 lbs |
| Recovery, compressor operating | 90% minimum | 80% (wrong, that is non operating) |
| Recovery, compressor NOT operating | 80% minimum | 90% (wrong, that is operating) |
| Recovery equipment manufacture cutoff | November 15, 1993 | November 15, 1992, 1995 |
| The 5 lb rule applies to | Manufactured charge (not current charge) | Current refrigerant charge |
90% vs 80% memory trick
Operating compressor means the higher requirement (90%); non operating is the lower floor (80%). The compressor is working, so push for full recovery. The compressor is not working, so 80% is the floor.
EPA 608 Type II: leak rates and recovery vacuums
| Topic | Value | Common wrong answer |
|---|---|---|
| Comfort cooling leak rate threshold | 10% per year | 20% (wrong, that is commercial refrigeration) |
| Commercial refrigeration leak rate threshold | 20% per year | 10% (wrong, that is comfort cooling) |
| Industrial process leak rate threshold | 30% per year | 35% (wrong, that was the pre-2019 threshold) |
| Applies to systems with | 50 lbs or more refrigerant charge | 5 lbs or more, 20 lbs or more |
| Mandatory repair window | 30 days | 60 days (that is the extension), 90 days |
| One time repair extension | 60 days (in writing) | Automatic, unlimited |
| Recovery vacuum, R-22 class under 200 lbs | 0 in. Hg | 10 or 15 inches (wrong, those apply at 200 lbs or more) |
| Recovery vacuum, R-22 class 200 lbs or more | 10 in. Hg (post-1993 equipment; 4 in. Hg pre-1993) | 15 inches (wrong, that is CFC-12/R-500/R-502/R-114 class at 200+ lbs) |
| System evacuation (before charging) | 500 microns | 250 microns, 1000 microns |
| R-22 new equipment ban | January 1, 2010 | 2020 (that is all production) |
| R-22 all production ban | January 1, 2020 | 2010, 2023 |
The 10 20 35 pattern
Comfort cooling (10%), commercial refrigeration (20%), industrial process (30%). Study these in ascending order. The most common error is mixing up 10% and 20% between comfort cooling and commercial refrigeration.
EPA 608 Type III: low pressure chiller numbers
| Topic | Value | Common wrong answer |
|---|---|---|
| Recovery standard (equipment after Nov 15, 1993) | 25 mm Hg absolute | 10 inches Hg (that is Type II under 200 lbs) |
| Leak testing method | Dry nitrogen, 10 psig max | Pressurize with refrigerant (prohibited) |
| Purge unit location (draws from) | Top of condenser | Bottom of condenser |
| Type III refrigerants (examples) | R-11, R-113, R-123 | R-12 (wrong, R-12 is high pressure Type II) |
| R-11 atmospheric boiling point | 74.7°F | 40°F, 0°F |
| R-123 atmospheric boiling point | 82.2°F | 74.7°F (that is R-11) |
Most missed Type III concept: measurement units
Type II uses inches Hg vacuum. Type III uses mm Hg absolute. 25 mm Hg absolute is a deep vacuum, so do not confuse it with Type II vacuum levels.
Recovery vacuum standards quick reference
Recovery depth is measured in inches of mercury (in. Hg) vacuum for high pressure systems and mm Hg absolute for low pressure systems. Recovery equipment manufactured after November 15, 1993 must meet the deeper post 1993 standard. Memorize these tiers from 40 CFR §82.156:
| System size / refrigerant | Pre 1993 equipment | Post 1993 equipment |
|---|---|---|
| R-22 class, under 200 lbs | 0 in. Hg | 0 in. Hg |
| R-22 class, 200 lbs or more | 4 in. Hg | 10 in. Hg |
| CFC-12, R-500, R-502, R-114 at 200 lbs or more | 4 in. Hg | 15 in. Hg |
| Very high pressure (R-13, R-503) | 0 in. Hg | 0 in. Hg |
| Low pressure systems (Type III) | 25 mm Hg absolute | 25 mm Hg absolute |
Type I exception: small appliances use percentages instead of vacuum levels: recover 90% of the charge when the compressor operates, 80% when it does not, or evacuate to 4 in. Hg.
How the exam traps you here:
- Classify first, then recall. Underline the refrigerant family, system size, and compressor condition before reading the answer choices. Wrong classification makes the right vacuum number useless.
- Units flag the section. Inches Hg means Type II; mm Hg absolute means Type III.
- November 15, 1993 is a signal. Equipment made before or after that date can change the required recovery depth. On Type I questions the same date often disguises an active-vs-passive recovery question.
Leak rate thresholds memorization table
For appliances containing 50 lbs or more of refrigerant, EPA regulations set maximum allowable annual leak rates before mandatory repair or retrofit and retire action is required. These are frequently tested on all sections.
| System category | Max annual leak rate |
|---|---|
| Industrial process refrigeration | 30% |
| Commercial refrigeration | 20% |
| Comfort cooling (HVAC) | 10% |
When a leak is discovered, the owner must repair it within 30 days. If repair is not feasible, a retrofit or retirement plan must be submitted within 30 days and completed within 1 year. Technicians must provide a written statement of refrigerant added to the owner for systems with 50 lbs or more.
The easiest way to keep these values straight is to remember that industrial process refrigeration gets the highest threshold because those systems often run in demanding operating conditions, commercial refrigeration sits in the middle, and comfort cooling stays the lowest. Many older prep materials still teach a 15% comfort cooling figure, so the exam may present 10%, 15%, and 20% together to see whether you are relying on an outdated chart. Use the current threshold table on this page, not legacy notes copied from old manuals.
Leak rate questions also test procedure, not just the percentages. Once the threshold is exceeded, you should immediately think about the 30 day repair clock, the possibility of a retrofit or retirement plan if repair is not feasible, and the documentation obligations for appliances with 50 pounds or more of refrigerant. That sequence shows up in Core and Universal questions because it connects legal compliance with field practice. If the owner chooses to retire or retrofit instead of repair, the plan is not optional paperwork; it is the compliance path that replaces immediate repair.
Refrigerant classification quick reference
The exam tests refrigerant classification by chemical family, safety rating, and regulatory status. Key classifications:
| Refrigerant | Type | Safety class | Status |
|---|---|---|---|
| R-11 | CFC | A1 | Fully phased out (1996) |
| R-12 | CFC | A1 | Fully phased out (1996) |
| R-22 | HCFC | A1 | No new production (2020) |
| R-123 | HCFC | B1 | Active, low GWP HCFC |
| R-134a | HFC | A1 | AIM Act phasedown |
| R-410A | HFC blend | A1 | AIM Act phasedown |
| R-32 | HFC | A2L | Lower GWP replacement |
| R-454B | HFC blend | A2L | R-410A replacement |
| R-600a | Hydrocarbon | A3 | Common in small appliances |
| R-290 | Hydrocarbon | A3 | Growing use in commercial |
Safety class decoding: the letter is toxicity (A is lower, B is higher). The number is flammability (1 is no flame, 2L is mildly flammable, 2 is flammable, 3 is highly flammable). A2L refrigerants require special handling protocols and are a major focus of AIM Act transition questions. See AIM Act refrigerant changes for phasedown schedule details.
Group them by what the question is really testing:
- R-11, R-12: phaseout history and low pressure vs high pressure recognition
- R-22, R-123: HCFC identification and Type II vs Type III systems
- R-134a, R-410A: the familiar HFC examples in AIM Act questions
- R-32, R-454B: the lower GWP A2L transition
- R-600a, R-290: hydrocarbon flammability and safe handling
Decode the safety class every time instead of memorizing symbols: letter = toxicity (A lower, B higher), number = flammability (1 none, 2L mild, 3 high). It works even on refrigerants you have never seen.
Civil penalty and venting prohibition reference
The Core section and Universal exam both test civil penalty amounts and venting prohibition rules directly. These are not estimates, so memorize the exact figures:
- Venting prohibition effective date: July 1, 1992 (CFCs and HCFCs); extended to HFCs and blends under later regulations
- Civil penalty per violation: exceeds $44,539 per day per violation under 40 CFR Part 82.169 (adjusted for inflation; older guides list the outdated $37,500)
- De minimis exemption: releases of refrigerant that occur from normal operations (such as purging hoses) do not violate the venting prohibition when the release is minimized
- Technician certification required: any person who opens an appliance to service or repair it must be certified
- Reclaimed refrigerant standard: must meet the ARI 700 purity standard before resale
The wording trap: the exam may imply any release at all is illegal. Not quite. Intentional venting is prohibited; minimized, unavoidable releases from good faith service (like purging a hose) fall under de minimis. If an answer choice sounds casual about releasing refrigerant on purpose, it is wrong. Full regulation text: EPA.gov Section 608.
Memory hooks for the hardest numbers
| Number | Hook |
|---|---|
| July 1, 1992 vs Nov 15, 1995 | CFC comes first, alphabetically and chronologically. HFC = the Higher (later) date. |
| 90% vs 80% (Type I) | A working compressor works harder: operating = 90%. |
| 10 vs 15 in. Hg (Type II) | Bigger system, deeper vacuum: 200 lbs or more = 15 inches. |
| 500 microns | Evacuation before charging, never a recovery standard. |
| 25 mm Hg absolute | Type III only. Different unit = different section. |
| 18 of 25 | Passing every proctored section; open book Type I needs 21. |
Deep dive by section
This cheat sheet summarizes key numbers. For full context, explanations, and practice questions on each section:
- Core section study guide: Montreal Protocol, venting prohibitions, civil penalties, recovery certification
- Type I study guide: small appliances, passive recovery thresholds, piercing valves
- Type II study guide: high pressure systems, R-410A and R-22, leak rate tables, AIM Act HFC phasedown
- Type III study guide: low pressure chillers, R-123, purge units, moisture contamination
- Universal study guide: all sections combined, cross section comparisons, full exam strategy
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