EPA 608 cheat sheet: key numbers, dates, and rules to memorize

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.

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Current civil penalty	Exceeds $44,539 per day per violation	$37,500 (outdated)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 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

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	35% per year	30% (wrong, common approximation error)
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, under 200 lbs	10 inches Hg	15 inches (wrong, that is 200 lbs or more)
Recovery vacuum, 200 lbs or more	15 inches Hg	10 inches (wrong, that is under 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

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 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 is R-11)

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 tiers:

System size / refrigerant	Pre 1993 equipment	Post 1993 equipment
HCFC under 200 lbs, compressor working	0 psig	0 psig
HFC systems under 200 lbs	0 psig	0 psig
HFC and HCFC systems 200 lbs or more	4 in. Hg	4 in. Hg
High pressure systems, compressor non op	4 in. Hg	4 in. Hg
Low pressure systems (Type III)	25 in. Hg	25 in. Hg

Type I exception: passive recovery on small appliances requires 80% removal if the 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 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	35%
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.

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

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

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 full text lives at EPA.gov Section 608.

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:

• 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

Cheat sheet FAQ