EPA 608 Cheat Sheet: Key Numbers, Dates, and Rules to Memorize

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Every testable number, date, threshold, and regulatory rule organized by section — with common wrong answers flagged so you know exactly what to watch out for on exam day.

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're ready to attempt practice questions.

EPA 608 Core: Dates, Penalties, and Exemptions

Topic Value Common Wrong Answer
CFC/HCFC venting prohibition effective July 1, 1992 November 15, 1995 (wrong — that's HFC date)
HFC venting prohibition added November 15, 1995 July 1, 1992 (wrong — that's CFC/HCFC date)
Current civil penalty Exceeds $44,539/day per violation $37,500 (outdated)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 appears on competitors' sites. The current inflation-adjusted civil penalty exceeds $44,539 per day per violation. 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 10 lbs, 50 lbs
Recovery — compressor operating 90% minimum 80% (wrong — that's non-operating)
Recovery — compressor NOT operating 80% minimum 90% (wrong — that's operating)
Recovery equipment manufacture cutoff November 15, 1993 November 15, 1992, 1995
5-lb rule applies to Manufactured charge (not current charge) Current refrigerant charge

90% vs 80% Memory Trick

Operating compressor = higher requirement (90%); non-operating = lower (80%). The compressor is working → push for full recovery. The compressor isn't working → 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's commercial refrigeration)
Commercial refrigeration leak rate threshold 20% per year 10% (wrong — that's comfort cooling) or 15% (wrong)
Industrial process leak rate threshold 35% per year 30% (wrong — common approximation error)
Applies to systems with ≥50 lbs refrigerant charge ≥5 lbs, ≥20 lbs
Mandatory repair window 30 days 60 days (that's the extension), 90 days
One-time repair extension 60 days (in writing) Automatic, unlimited
Recovery vacuum — under 200 lbs 10 inches Hg 15 inches (wrong — that's ≥200 lbs)
Recovery vacuum — 200 lbs or more 15 inches Hg 10 inches (wrong — that's <200 lbs)
System evacuation (before charging) 500 microns 250 microns, 1000 microns
R-22 new equipment ban January 1, 2010 2020 (that's 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 (35%). 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 (post-Nov 15, 1993 equipment) 25 mm Hg absolute 10 inches Hg (that's Type II <200 lbs)
Leak testing method Dry nitrogen at 0 psig only 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's 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 — do not confuse with Type II vacuum levels.

Recovery Vacuum Standards Quick Reference

Recovery depth is measured in inches of mercury (in. Hg) vacuum or psig. Equipment manufactured after November 15, 1993 must meet the higher post-1993 standard. Memorize these three tiers:

System Size / RefrigerantPre-1993 EquipmentPost-1993 Equipment
HCFC <200 lbs, compressor working0 psig0 psig
HFC systems under 200 lbs0 psig0 psig
HFC/HCFC systems 200+ lbs4 in. Hg4 in. Hg
High-pressure systems, compressor non-op4 in. Hg4 in. Hg
Low-pressure systems (Type III)25 in. Hg25 in. Hg

Type I exception: System-dependent (passive) recovery on small appliances requires 80% removal if compressor works, 90% if it does not. Self-contained active recovery always requires 90% regardless of compressor status.

These numbers matter because exam questions often hide the deciding factor in one phrase: whether the appliance is a small appliance, a high-pressure appliance, or a low-pressure chiller. If you do not first classify the equipment correctly, you can know the vacuum numbers and still miss the answer. A strong test-day habit is to underline the refrigerant family, system size, and compressor condition before looking at the answer choices. That prevents confusing the Type II vacuum figures with the Type III absolute pressure standard.

Another frequent trap is the November 15, 1993 equipment manufacture date. The EPA uses that cutoff throughout Section 608 to distinguish older recovery equipment standards from newer standards. When a question asks whether recovery equipment was manufactured before or after that date, treat it as a signal that the required recovery depth may change. On Type I questions, the same date can appear even when the real concept being tested is active versus passive recovery. Read the full prompt, not just the numbers.

Leak Rate Thresholds — Memorization Table

For appliances containing 50+ lbs of refrigerant, EPA regulations set maximum allowable annual leak rates before mandatory repair or retrofit/retire action is required. These are frequently tested on all sections.

System CategoryMax Annual Leak Rate
Industrial process refrigeration35%
Commercial refrigeration20%
Comfort cooling (HVAC)15%
All other appliances 50+ lbs15%

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 50+ lbs.

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 lower. Many older prep materials still teach a 10% 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:

RefrigerantTypeSafety ClassStatus
R-11CFCA1Fully phased out (1996)
R-12CFCA1Fully phased out (1996)
R-22HCFCA1No new production (2020)
R-123HCFCB1Active — low GWP HCFC
R-134aHFCA1AIM Act phasedown
R-410AHFC blendA1AIM Act phasedown
R-32HFCA2LLower GWP replacement
R-454BHFC blendA2LR-410A replacement
R-600aHydrocarbonA3Common in small appliances
R-290HydrocarbonA3Growing use in commercial

Safety class decoding: Letter = toxicity (A = lower, B = higher). Number = flammability (1 = no flame, 2L = mildly flammable, 2 = flammable, 3 = 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.

Classification tables become much easier to memorize when you group the refrigerants by why they matter on the exam. R-11 and R-12 are usually there to test phaseout history and low-pressure versus high-pressure recognition. R-22 and R-123 show up when the exam wants you to identify HCFCs or distinguish Type II from Type III systems. R-134a and R-410A are often used as familiar HFC examples, while R-32 and R-454B signal the industry transition toward lower-GWP A2L options. R-600a and R-290 usually point to hydrocarbon safety and flammability questions.

Do not memorize the letters and numbers in the safety class code as abstract symbols. Translate them every time. A means lower toxicity. B means higher toxicity. The number describes flammability, with A1 refrigerants being nonflammable under the test conditions and A3 refrigerants being highly flammable. That decoding process helps on unfamiliar refrigerants because even if you do not recognize the product name immediately, you can still reason through what the safety class implies for handling, storage, and ignition risk. This is especially useful when modern A2L refrigerants are compared with older A1 refrigerants in transition-era questions.

Civil Penalty and Venting Prohibition Reference

Core section and Universal exam both test civil penalty amounts and venting prohibition rules directly. These are not estimates — memorize the exact figures:

These rules are foundational because they explain why the rest of the recovery and leak-repair standards exist. Section 608 is not just a technical exam; it is a regulatory exam tied to environmental compliance. Questions about venting, recovery, recordkeeping, and certification are all different expressions of the same legal principle: refrigerant must be handled in a way that minimizes emissions to the atmosphere. When you study the exact dates and penalty figures, connect them to that larger compliance purpose so the numbers are easier to remember under pressure.

The venting prohibition is also a favorite source of tricky wording. The exam may ask whether any release at all is illegal, which is not quite correct. The de minimis concept matters because incidental releases from normal good-faith service practices can be permitted when minimized, such as a small amount released while connecting or disconnecting hoses. The key is that intentional venting is prohibited, while unavoidable releases must be kept as small as possible. If an answer choice sounds casual about letting refrigerant out on purpose, it is almost always wrong.

Deep Dive by Section

This cheat sheet summarizes key numbers — for full context, explanations, and practice questions on each section:

Cheat Sheet FAQ

What numbers do I need to memorize for the EPA 608 exam?
Core: 1992 (CFC/HCFC ban), 1995 (HFC ban), $44,539+ penalty, 0.1 oz de minimis. Type I: 5 lbs charge limit, 90%/80% recovery. Type II: 10%/20%/35% leak rates, 10/15 inches Hg vacuum. Type III: 25 mm Hg absolute recovery. Universal: 72% passing (18/25 per section).
What is the annual leak rate for commercial refrigeration?
20% per year (for systems with ≥50 lbs of refrigerant charge). Not 10% (that's comfort cooling) and not 15% (that number doesn't appear in the regulation).
Is there a physical cheat sheet allowed during the EPA 608 exam?
No — proctored exams are closed-book. Memorize the number bank before your exam date. The Type I open-book mail-in format is the only exception, and it uses a higher 84% passing threshold.
What is the passing score for EPA 608?
18 of 25 correct (72%) per section for all proctored exams. The Type I open-book mail-in exam requires 84% (21 of 25).

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Part of the EPA 608 Study Guides Collection

This cheat sheet is part of our complete EPA 608 study guides library — with full section-by-section breakdowns for Core, Type I, Type II, Type III, and Universal exams.