Core

25% of the EPA 608 · blueprint 40 CFR part 82 subpart F, appendix D, section d (test content)

Short answer

Core is 25 of the items on whichever Section 608 test you sit, and 25 of the 100 on Universal. Appendix D fixes its three areas: the environmental impact of CFCs, HCFCs and substitute refrigerants; laws and regulations; and the changing industry outlook. EPA's own topic list adds refrigerant identification, the three R definitions, recovery technique, dehydration evacuation, safety and cylinder handling, and shipping labels.

Why it matters on this exam

Core is the only section you cannot avoid. Every certification path includes the same 25 Core items, so a weak Core costs you on Type I, Type II, Type III and Universal alike. It is also the cheapest section to fix, because most of it is definitions and rules rather than technique.

One rule about Core decides how you book: an open-book Core test cannot count toward Universal certification. To reach Universal the Core test must be proctored.

Key concepts

Ozone depletion and the ranking. Chlorine destroys stratospheric ozone. CFCs have the highest ozone depletion potential, HCFCs less, HFCs zero because they contain no chlorine. Know that R-12 is a CFC, R-22 an HCFC and R-134a an HFC — EPA's topic list says explicitly that you need the idea, not the chemical formulas.
The venting prohibition. Section 82.154(a) makes it unlawful to knowingly vent or release refrigerant while maintaining, servicing, repairing or disposing of an appliance. It applies at servicing and at disposal, and to non-exempt substitutes too: Clean Air Act section 608(c)(2) has extended the venting prohibition to substitute refrigerants since 15 November 1995. A short list is exempt: carbon dioxide, nitrogen and water in any application; ammonia in commercial or industrial process refrigeration and absorption units; chlorine and hydrocarbons in the industrial process refrigeration of those substances; R-170 in very low temperature refrigeration and non-mechanical heat transfer equipment; and R-290 (propane), R-600a (isobutane) and R-441A in the specific end-uses the rule lists.
The three Rs. Recover is removing refrigerant from a system and storing it. Recycle is cleaning it for reuse by oil separation and single or multiple passes through filter-driers. Reclaim is reprocessing to new-product specification, verified by chemical analysis — the standard is AHRI 700.
System-dependent versus self-contained. System-dependent ("passive") recovery relies on the appliance's own compressor or pressure; self-contained equipment has its own means of pulling refrigerant out. The distinction drives the Type I questions and the 15-pound prohibition in Type II.
Cylinder safety. Never fill a cylinder more than 80 percent. Recovery cylinders are DOT-approved and colour coded yellow and gray; disposable cylinders are never refilled. Use nitrogen, never oxygen or compressed air, for leak detection, and always with a pressure regulator and a relief valve.
Refrigerant exposure. Oxygen deprivation, cardiac sensitisation, frostbite. Gloves and goggles as standard; self-contained breathing apparatus in extreme cases.

Common mistakes

Treating the venting ban as applying only to CFCs. It reaches any class I or class II refrigerant and any non-exempt substitute; the Clean Air Act has prohibited venting substitutes since 15 November 1995.
Confusing recycle with reclaim. Recycling happens in the field to a lower standard; reclaiming is reprocessing to AHRI 700 purity and it cannot be done on a job site.

Worked example

A technician finishes a repair and has a partly filled recovery cylinder on the truck. Two Core rules bite at once. The cylinder may not be filled beyond 80 percent of capacity, because liquid refrigerant expands as it warms and a hydrostatically full cylinder can rupture. And it must carry the refrigerant identification and the DOT classification tag before it ships. Neither is about the repair; both are the kind of thing Core asks.

Original practice questions

CoreDifficulty 2/5

Since 1 January 2018, the venting prohibition in 40 CFR 82.154 has applied to refrigerant released while servicing which appliances?

AThose containing any class I or class II refrigerant or a non-exempt substitute
BThose containing a class I refrigerant that has not yet been fully phased out
CThose containing a class I or class II refrigerant but no substitute refrigerant
DThose containing more than fifty pounds of any refrigerant covered by the rule

Show answer and rationale

Correct: A. The 2018 expansion is the single most commonly missed Core fact. Section 82.154(a)(1) reaches any class I or class II refrigerant and any non-exempt substitute, with a short exemption list that includes carbon dioxide, nitrogen, water and specified hydrocarbon end-uses.

B — The ban was never limited to refrigerants still in production; phase-out status is irrelevant to it.
C — This was the position before 1 January 2018, when the rule was extended to non-exempt substitutes.
D — The fifty-pound threshold belongs to the leak repair rules in 82.157, not to the venting prohibition.

CoreDifficulty 3/5

What distinguishes reclaiming refrigerant from recycling it?

AReclaiming returns the refrigerant to the same appliance it was removed from
BReclaiming reprocesses refrigerant to a specification verified by chemical analysis
CReclaiming removes the refrigerant from the appliance and stores it in a cylinder
DReclaiming cleans the refrigerant by oil separation and passes through a filter-drier

Show answer and rationale

Correct: B. Reclaiming means reprocessing to new-product purity, confirmed by chemical analysis against the AHRI 700 standard. It cannot be done on a job site, which is the practical consequence the exam is testing.

C — That describes recovery, which is simply removing refrigerant and storing it externally.
D — That describes recycling, a field-level clean-up that does not meet the reclaim specification.
A — Where the refrigerant ends up does not define the term; the purity standard reached does.

CoreDifficulty 1/5

A recovery cylinder must not be filled beyond what proportion of its capacity?

ASeventy percent, because the cylinder must be weighed before it is transported
BSixty percent, because the relief valve cannot operate above that fill level
CEighty percent, because liquid refrigerant expands as its temperature rises
DNinety percent, because the remaining space allows vapour to be drawn off

Show answer and rationale

Correct: C. Overfilling is a rupture risk: a cylinder filled hydrostatically full has nowhere to expand into when it warms, and the vapour space is what absorbs that expansion.

D — Ninety percent is the small-appliance recovery threshold for a working compressor, not a fill limit.
A — Weighing a cylinder is required practice, but seventy percent is not the regulatory fill limit.
B — Relief valves are not rated by fill percentage, and sixty percent is not the figure in the rule.

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Primary references

Appendix D to Subpart F of Part 82 — Standards for Becoming a Certifying Program for Technicians — Office of the Federal Register (eCFR) · government · retrieved 2026-09-22, verified 2026-09-22
Section 608 Test Topics — United States Environmental Protection Agency · primary · retrieved 2026-09-22, verified 2026-09-22
40 CFR Part 82 Subpart F — Recycling and Emissions Reduction — Office of the Federal Register (eCFR) · government · retrieved 2026-09-22, verified 2026-09-22

Last reviewed: 2026-10-18Next review by: 2026-12-17Reviewed by: Openverse editorial team, Authoring and fact verificationHow we verify facts