Core: Ozone, the Clean Air Act, and the Three R's
Every technician who buys or handles refrigerant must first pass the Core section, because it explains why the rules exist. This chapter covers how refrigerants damage the ozone layer, what Section 608 of the Clean Air Act requires, the recover-recycle-reclaim system, and the production phaseouts that are steadily changing which refrigerants you will work with.
Ozone Depletion and Refrigerants
The stratospheric ozone layer, roughly 6 to 30 miles above the earth, absorbs most of the sun's harmful ultraviolet radiation. Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are stable enough to drift up to the stratosphere, where UV light breaks them apart and releases chlorine atoms. A single chlorine atom can destroy tens of thousands of ozone molecules before it is removed, which is why even small refrigerant leaks matter. A refrigerant's ozone depletion potential (ODP) measures this damage relative to CFC-11, which is set at 1.0. CFCs such as R-11 and R-12 have the highest ODP; HCFCs such as R-22 contain less chlorine and do less damage; and HFCs such as R-410A contain no chlorine and have an ODP of zero. Refrigerants also carry a global warming potential (GWP), so today's rules target both ozone loss and climate impact.
Section 608 and the Venting Prohibition
Section 608 of the Clean Air Act, carried out through 40 CFR Part 82, is the federal law that governs the service, maintenance, repair, and disposal of stationary air-conditioning and refrigeration equipment. Its centerpiece is the venting prohibition: since July 1, 1992, it has been illegal to knowingly release CFC and HCFC refrigerants into the atmosphere during service or disposal, and the ban was extended to their HFC substitutes on November 15, 1995. There are only a few narrow exceptions, such as small releases that happen during good-faith connecting and disconnecting of recovery equipment, or de minimis quantities that cannot be recovered with required equipment. Nitrogen used for leak testing or purging is not a refrigerant and may be released. Anyone who maintains, services, repairs, or disposes of covered appliances must be an EPA-certified technician.
The Three R's: Recover, Recycle, Reclaim
The Clean Air Act builds refrigerant conservation around three actions with distinct meanings. To recover is simply to remove refrigerant from an appliance in any condition and store it in an external container, without testing or processing it. To recycle is to clean recovered refrigerant for reuse by reducing its oil, moisture, and acidity, usually with an oil separator and single or multiple passes through filter-driers; recycling happens on-site or at a local shop and does not verify purity by chemical analysis. To reclaim is to reprocess refrigerant to the purity of new product, verified by chemical analysis to meet the AHRI Standard 700 specification. Only an EPA-certified reclaimer may reclaim refrigerant, and refrigerant that changes ownership generally must be reclaimed before it is resold. Knowing these three definitions is one of the most heavily tested Core topics.
Phaseouts and the Montreal Protocol
The 1987 Montreal Protocol is the international treaty that set the timetable for ending ozone-depleting substances, and the United States carries out its commitments through the Clean Air Act. CFC production and import in the U.S. ended on January 1, 1996, which is why CFC-12 and CFC-11 are now available only from recovered and reclaimed stock. HCFCs followed on a later schedule: production and import of virgin HCFC-22 for new equipment ended January 1, 2010, and virtually all HCFC production and import ended January 1, 2020, leaving only reclaimed and previously produced supply for servicing older units. More recently the American Innovation and Manufacturing (AIM) Act directs EPA to phase down high-GWP HFCs such as R-404A and R-410A. As each refrigerant becomes scarce and expensive, recovery and reclamation grow more important for keeping existing equipment running.
Refrigerant Blends and Substitutes
Many modern refrigerants are blends of two or more pure compounds, and how a blend behaves determines how you must handle it. A zeotropic blend, such as R-407C or R-404A, has components that boil and condense at slightly different temperatures, producing a temperature glide as the mixture changes state. Because the lighter components escape first, a leaking or vapor-charged zeotropic blend can fractionate and shift its composition, so these blends must be charged as a liquid to keep the proportions correct. An azeotropic blend, such as R-502, behaves like a single refrigerant with almost no glide. EPA's Significant New Alternatives Policy (SNAP) program reviews and approves substitute refrigerants for each end use, and a substitute may only be used in the applications for which it is listed acceptable. Never mix refrigerants in a system, because the result cannot be recycled or reclaimed.
Last updated: July 2026