608 Study Buddy
Back to blog

EPA 608 leak rates: are 15% and 35% still correct?

Clipboard of leak-rate percentages with 15 percent and 35 percent crossed out and 10, 20, and 30 percent written in
  • 608 Study Buddy
  • 6 min read
  • Last reviewed
10%comfort cooling
20%commercial refrigeration
30%industrial process

A common question in exam-preparation discussions is why two study sheets give different numbers. Sometimes one sheet is outdated. Sometimes both numbers remain valid but answer different questions. The solution is to attach every number to its rule, appliance category, unit, and effective period.

Where the old 15/35 figures came from

Technician at a workbench comparing old yellowed study notes with a modern binder and tablet, crossing out an old sheet with a pencil, a coffee mug nearby
Older study notes still show historical leak provisions that applied only through January 1, 2019; after that date the category-specific 10/20/30 thresholds in 82.157 apply instead.

The historical leak provisions still visible in 40 CFR 82.156(i) explain much of the confusion. Their applicability ends at January 1, 2019, when the provisions in 82.157 apply instead. Finding an old percentage on a government page is therefore not enough; you must read the paragraph that says when it applies.

This is a useful source-reading lesson. A search engine can land you halfway down a regulation, directly beside a number. Scroll upward to the applicability language before copying it into notes. Regulations may preserve earlier provisions to explain past obligations without making them the rule for a current question.

For today's Section 608 leak-repair study, use the category-specific 10/20/30 thresholds in 82.157(c)(2). Our leak-repair guide develops the current framework; this article helps you recognize when an older shortcut is steering you away from it.

Keep the two charge thresholds separate

Section 82.157 applies to appliances with a full charge of 50 pounds or more of class I or class II refrigerant, or a blend containing such refrigerant. It does not apply to appliances containing solely substitute refrigerants. The relevant distinction is not simply “large system” or “commercial building.”

AIM leak repair under 40 CFR 84.106 has a different scope. Beginning January 1, 2026, it applies to covered appliances with at least 15 pounds of refrigerant containing an HFC or a substitute for an HFC with a global warming potential greater than 53. Its exclusions include appliances containing solely an ozone-depleting refrigerant and the residential and light-commercial air-conditioning and heat-pump subsector.

The AIM provision uses the same 10/20/30 pattern for its stated categories, but the similar percentages do not make the two provisions one rule. AIM did not simply replace the 50-pound Section 608 threshold with 15 pounds. Identify the refrigerant, full charge, and application before selecting the applicable provision.

Imagine two study questions that both describe 20 pounds of refrigerant. One identifies a covered HFC commercial refrigeration appliance; the other identifies residential air conditioning. The shared weight does not settle the answer. The subsector and exclusions are part of the information you must use.

See our AIM Act guide for the wider program context. When making flashcards, give Section 608 and AIM separate cards, even where their percentages match. Write the applicability conditions on the question side so you practice recognizing the rule instead of guessing from the weight alone.

Ten and fifteen inches of vacuum are still current

Portable refrigerant recovery machine on a rooftop beside a condensing unit, one hose from the unit service port to the machine and one hose from the machine to a grey recovery cylinder with a yellow top on a scale
Recovery to the 10-inch and 15-inch Hg vacuum values remains in current Table 1 of 40 CFR 82.156; choose the correct row and equipment-date column rather than applying one value to every appliance.

Do not “update” your notes by deleting the 10-inch and 15-inch Hg vacuum values. Both remain in current Table 1 of 40 CFR 82.156. The mistake is applying one of them to every appliance, rather than choosing the correct row and equipment-date column.

For recovery or recycling equipment manufactured or imported on or after November 15, 1993, Table 1 includes 10 inches Hg vacuum for high-pressure appliances with a full charge of 200 pounds or more. It also lists 10 inches for medium-pressure appliances below 200 pounds, and 15 inches for medium-pressure appliances with 200 pounds or more.

Those values belong to the named rows. The newer-equipment column gives zero inches for very-high-pressure appliances and high-pressure appliances below 200 pounds. The low-pressure row uses 25 millimeters Hg absolute, a different unit and reference. Do not treat every number with “Hg” beside it as interchangeable.

The date heading refers to the recovery or recycling equipment, not simply the year the customer's appliance was installed. Our recovery and evacuation table puts the rows and both date columns together. Read the complete table and its surrounding conditions rather than using this comparison as a field procedure.

A penalty amount needs its own source

A memorized civil-penalty dollar figure can become stale because federal penalty amounts are adjusted for inflation. The relevant reference is 40 CFR 19.4. Its tables distinguish statutory provisions and applicable dates, including when violations occurred and when penalties are assessed.

We do not print a single penalty amount here. Removing the date conditions from a table and labeling the result “the EPA fine” creates a misleading shortcut. If a study source gives an amount, check its citation and date rather than copying the largest number visible on the page.

For revision notes, record the source and the reason a number may change. That gives you a way to verify a later edition of a guide without starting from memory. A dated source note is especially useful when old practice sheets continue circulating after newer regulatory material is available.

Repair an old study sheet without discarding everything

Highlight each standalone number and ask what question it answers. Add its unit, equipment category, charge condition, date condition, and source. If one of those is missing, return to the original rule before deciding that the number is wrong.

Separate historical content from current material. Keep historical percentages only if you are deliberately studying an earlier period, and label that purpose clearly. For current exam preparation, practice explaining why the present rule applies instead of retaining an unlabeled collection of old and new values.

Common myths

Myth “Every 15-pound appliance follows the same leak rule.”

Fact Refrigerant and application exclusions matter.

Myth “Ten and fifteen inches were removed.”

Fact They remain in current Table 1 for specified rows.

Myth “A government page always shows only current obligations.”

Fact Read the applicability dates around historical provisions.

Myth “One penalty amount works forever.”

Fact Consult 40 CFR 19.4 and its date conditions.

Study disclaimer: This is exam-study material, not legal advice or field-service instructions. Consult the linked EPA and eCFR sources for current requirements.

Sources

Check yourself

Under Section 608, what are the current leak-rate thresholds for comfort-cooling and industrial-process-refrigeration appliances containing 50 pounds or more of ozone-depleting refrigerant?

Show answer

Answer: A. Comfort cooling: 10%; industrial process refrigeration: 30%.

For Section 608 appliances containing 50 pounds or more of ozone-depleting refrigerant, comfort cooling uses a 10% annual threshold and industrial process refrigeration uses 30%. Commercial refrigeration is a separate category at 20%.

Section 608 owner/operator service recordkeeping under 40 CFR 82.157 applies to covered ozone-depleting-refrigerant appliances with a full charge of how many pounds or more?

Show answer

Answer: D. 50 pounds

The threshold for this Section 608 program is 50 pounds or more of an ozone-depleting refrigerant. This is not a blanket exemption for smaller equipment: the AIM Act and disposal rules have separate applicability and record requirements. Source: 40 CFR 82.157(a), (l).

Why should a technician check current EPA civil-penalty limits rather than memorize an old dollar amount?

Show answer

Answer: D. Maximum civil penalties are adjusted for inflation.

EPA adjusts civil monetary penalty limits for inflation. Applicable amounts depend on the violation and relevant dates; old study-guide dollar figures are not reliable current limits. Source: 40 CFR 19.4.

Practice this

Try the free Type II practice test. For every numerical answer, say the appliance category, rule, and unit before choosing a value.

Take the Type II practice test

Read next