Your FREE EPA 608 Flashcards 2026 – 200+ Cards

Ozone Depletion Potential — how much a substance harms stratospheric ozone, relative to CFC-11 (1.0).

Global Warming Potential — how much heat a gas traps over time, relative to carbon dioxide (1.0).

Chlorofluorocarbon — an early refrigerant (e.g., R-12) with high ozone depletion potential.

Hydrochlorofluorocarbon — a transitional refrigerant (e.g., R-22) with lower ODP than a CFC.

Hydrofluorocarbon — a chlorine-free refrigerant (e.g., R-410A) with zero ODP but high GWP.

Hydrofluoroolefin — a newer refrigerant (e.g., R-1234yf) with zero ODP and very low GWP.

The Clean Air Act — the U.S. federal law the EPA uses to regulate refrigerant handling.

No. Knowingly venting refrigerant during service, repair, or disposal has been illegal since 1995.

A small, unavoidable release of refrigerant during good-faith recovery — not treated as illegal venting.

Remove refrigerant from an appliance and store it in an external container, without cleaning or testing it.

Clean recovered refrigerant on-site (oil separation, filter-driers) for reuse in the same owner's equipment.

Reprocess refrigerant to like-new purity meeting AHRI 700 and verify it chemically — the only refrigerant resold to a new owner.

Only reclaimed refrigerant — it must meet the AHRI 700 purity standard and be lab-verified.

AHRI 700 — the industry standard for like-new refrigerant purity.

Only technicians certified under Section 608 (or 609 for motor-vehicle AC); the rule now covers most HFCs.

No — it is a one-time, lifetime credential with no renewal or CEUs required.

EPA-approved certifying organizations (e.g., ESCO Institute, Mainstream Engineering, HVAC Excellence) — not the EPA itself.

In the stratosphere, well above the weather at ground level.

Harmful ultraviolet (UV) radiation from the sun.

Higher rates of skin cancer and cataracts from increased ground-level UV radiation.

It is so stable it drifts up to the stratosphere, where UV light eventually frees its chlorine.

Ultraviolet (UV) light in the stratosphere splits the molecule and releases a chlorine atom.

It acts as a catalyst, destroying thousands of ozone molecules before it is removed.

Carbon dioxide (CO₂), which is set at a GWP of 1.0.

CFC-11, which is set at an ODP of 1.0.

Yes — HFCs like R-410A do not deplete ozone but still trap a lot of heat (high GWP).

The 1987 international treaty that set the schedule for phasing out ozone-depleting substances.

1987.

HCFCs were lower-ODP transitional refrigerants, so CFCs (the worst for ozone) were eliminated first.

January 1, 2020.

By using recovered, recycled, or reclaimed R-22 from existing stock — no new R-22 is produced.

The American Innovation and Manufacturing Act of 2020, directing the EPA to phase down high-GWP HFCs.

Climate (GWP). HFCs have zero ODP, so the AIM Act phases them down for their warming potential.

About 85% over 15 years.

It is illegal to knowingly vent regulated refrigerant during service, maintenance, or disposal.

Gray body with a yellow top (shoulder).

80% of capacity by weight — liquid refrigerant expands as it warms and can rupture an overfilled cylinder.

Liquid refrigerant expands as temperature rises; an overfilled cylinder can rupture.

Every 5 years (DOT requirement).

No — it is illegal to refill a disposable (one-time-use) cylinder.

Evacuate it to a deep vacuum so it is empty before recycling the metal.

Asphyxiation — the vapor displaces oxygen; ventilate and use an oxygen-deprivation monitor.

Frostbite — it is extremely cold; wear gloves and eye protection.

It can form toxic gases (such as phosgene) — never expose refrigerant to a flame.

An EPA-certified facility that reprocesses used refrigerant to AHRI 700 purity for resale.

An electronic detector that finds halogen-containing refrigerant leaks (CFCs, HCFCs, HFCs).

Some refrigerants conduct or react in ways that matter for electrical safety; follow manufacturer handling rules.

Records showing refrigerant was recovered before disposal must be kept per EPA requirements.

Section 609 — Section 608 covers stationary equipment.

A non-ozone-depleting refrigerant (often an HFC or HFO) used in place of a CFC or HCFC.

Yes — the prohibition was extended to most HFC substitute refrigerants, not just ozone-depleting ones.

Pulling a deep vacuum to remove moisture and noncondensables before charging.

Microns (1 micron = 0.001 mm Hg); about 500 microns is a typical deep-vacuum target.

A micron (vacuum) gauge.

Moisture forms acids and ice, causing corrosion, restrictions, and component failure.

A mildly flammable, low-toxicity refrigerant class (e.g., many HFOs) used as a low-GWP replacement.

It has a high GWP, so it is being phased down even though it has zero ODP.

Newly manufactured refrigerant that has never been used, meeting purity specifications.

Active recovery gear with its own compressor that can pull refrigerant from an appliance on its own.

Passive recovery that uses the appliance's own compressor or pressure; allowed only on small appliances.

For a given refrigerant, pressure and saturation temperature change together — read with a P/T chart.

To prove it meets EPA performance standards for how much refrigerant it recovers.

It prevents ozone depletion and climate impact and conserves valuable refrigerant for reuse.

O₃ — a molecule of three oxygen atoms that, in the stratosphere, absorbs UV radiation.

The lowest atmospheric layer where weather occurs; ground-level ozone here is a pollutant, not protective.

Ground-level ozone is smog (harmful to breathe); stratospheric ozone shields Earth from UV.

A common CFC refrigerant (high ODP) once used in refrigerators and car AC; now banned from production.

An HFC refrigerant (zero ODP, high GWP) widely used in refrigeration and older mobile AC.

A mix of refrigerants whose components boil at different temperatures, causing temperature glide.

The temperature range over which a zeotropic blend evaporates or condenses; charge as a liquid.

To keep the blend's proportions correct; charging as vapor can fractionate the components.

Separation of a blend's components so the mix no longer matches its spec — avoid by liquid charging.

The U.S. Environmental Protection Agency (EPA).

Yes — illegal venting can result in significant civil penalties under the Clean Air Act.

Equipment tested and certified to meet EPA recovery performance standards.

An HCFC contains hydrogen, making it less stable and lower-ODP than a CFC.

The hydrogen makes the molecule break down lower in the atmosphere, so less chlorine reaches the ozone layer.

An EPA program that reviews and lists acceptable substitute refrigerants.

Its production and import are banned on a schedule (e.g., CFCs, then HCFCs).

Its production/consumption is reduced over time but not fully banned — e.g., HFCs under the AIM Act.

Gloves and eye protection (safety glasses or goggles).

An oxygen-deprivation (oxygen) monitor.

To verify a system holds vacuum (a leak/standing-vacuum test) and to remove noncondensables.

Factory-sealed so the refrigerant circuit is airtight and closed.

A float or shutoff that prevents filling a recovery cylinder past the safe 80% level.

EPA requires recordkeeping to verify proper recovery, recycling, reclamation, and disposal.

To remove moisture and contaminants from refrigerant during on-site recycling.

To keep refrigerant out of the atmosphere by reusing it rather than venting and replacing it.

A product fully manufactured, charged, and hermetically sealed at the factory with 5 lb or less of refrigerant.

5 pounds or less of refrigerant.

It must be fully manufactured, charged, and hermetically sealed at the factory.

No — a field-assembled or field-charged unit is never a small appliance, regardless of charge.

Household refrigerators, freezers, window AC, PTACs, dehumidifiers, water coolers, and vending machines.

Recover at least 90% of the charge (post-Nov 15 1993 equipment).

Recover at least 80% of the charge (post-Nov 15 1993 equipment).

A working compressor helps push refrigerant out, so more (90%) can be recovered.

November 15, 1993 — the cutoff for the higher post-1993 recovery efficiencies.

Only small appliances.

Passive recovery using the appliance's own compressor or internal pressure to push refrigerant out.

No — system-dependent recovery is permitted only on small appliances.

Treat it as non-operating: recover at least 80% of the charge.

Yes — Type I covers both servicing and disposal of small appliances.

Through some EPA-approved organizations it can be taken open-book and proctored by mail.

To access a sealed system for recovery; it taps into the line for the recovery device.

It depends on the appliance's own pressure/compressor, so it works only on small charges (small appliances).

Yes — 80% is the minimum when the compressor is inoperative.

Historically R-12 and R-134a in refrigerators; R-600a (isobutane) in many newer units.

Isobutane — a low-GWP, mildly flammable hydrocarbon refrigerant used in many small appliances.

They are flammable; follow special handling, charge limits, and ignition-source precautions.

Propane — a flammable hydrocarbon refrigerant used in some self-contained small appliances.

Yes — it must meet the recovery standards for post-1993 small-appliance equipment.

A self-contained through-the-wall unit (hotels, apartments) that is typically a small appliance.

Recover at least 90% of the charge.

The window unit is factory-sealed and charged; the split system is field-assembled and field-charged.

90% recovery with the compressor running, 80% with it not running (small appliances).

Yes — if it's factory-sealed with 5 lb or less of refrigerant.

Yes — typically factory-sealed with a small charge.

A piercing/saddle (line-tap) valve to connect the recovery device.

Yes — you may use self-contained equipment on small appliances; passive is also allowed only here.

At least 90% of the charge.

At least 80% of the charge.

Without the compressor's help, the standard is set lower (80%).

Control ignition sources and follow charge limits for R-600a/R-290 hydrocarbon refrigerants.

High- and very high-pressure appliances — split AC, heat pumps, and supermarket refrigeration racks.

R-22, R-410A, R-404A, and R-407C.

A high-pressure HCFC historically used in residential and commercial AC; production/import ended in 2020.

A very high-pressure HFC that replaced R-22 in modern AC and heat pumps; zero ODP, high GWP.

R-410A operates at substantially higher pressures, so tools and recovery gear must be rated for it.

Commercial and supermarket refrigeration (a high-pressure HFC).

0 inches of mercury vacuum (atmospheric), with post-1993 equipment.

10 inches of mercury vacuum, with post-1993 equipment.

200 pounds — above it, the required vacuum increases (to 10 in. Hg with post-1993 gear).

Inches of mercury (in. Hg) vacuum.

Appliances containing 50 pounds or more of refrigerant.

An annual leak rate above 10%.

An annual leak rate above 20%.

An annual leak rate above 30%.

Within 30 days of discovery (or follow an approved retrofit/retirement plan).

A follow-up verification (leak) test confirming the leaks are fixed.

Large charges leaking at high rates release the most refrigerant, so repair is most beneficial.

Self-contained (active) recovery equipment — not passive recovery.

About 500 microns (a deep vacuum), measured with a micron gauge.

To remove moisture and noncondensables before recharging.

The temperature of refrigerant vapor above its saturation temperature — used to check charge.

The temperature of liquid refrigerant below its saturation temperature — used to check charge.

As an R-22 retrofit replacement refrigerant (a high-pressure HFC blend).

R-410A's higher operating pressure requires gauges and equipment rated for those pressures.

A safety control that shuts the system down if discharge pressure rises too high.

200 lb charge cutoff and 0 vs 10 in. Hg vacuum (≤200 lb vs >200 lb, post-1993).

Equipment using refrigerants like R-410A or R-13 that operate at especially high pressures (covered by Type II).

Yes — leak-repair requirements have been extended to substitute refrigerants such as HFCs.

A field-installed AC with separate indoor and outdoor units — a Type II high-pressure appliance.

A reversible AC that heats or cools; high-pressure equipment under Type II.

Over 200 lb the required vacuum increases (to 10 in. Hg with post-1993 gear).

0 in. Hg — it is at or below the 200-lb cutoff.

10 in. Hg vacuum — it is above the 200-lb cutoff (post-1993 gear).

Yes if it exceeds the 10% annual leak rate (it's over the 50-lb threshold).

No — leak-repair requirements apply at 50 lb or more.

Document the leak rate, repair, and the follow-up verification test.

It operates at notably higher pressures than R-22, requiring higher-rated equipment.

To confirm a deep evacuation (about 500 microns) during dehydration.

To find a refrigerant's saturation temperature at a given pressure when checking charge.

Recovery-only just removes refrigerant; a recovery/recycle machine also cleans it on-site.

Low-pressure appliances — centrifugal chillers that operate under a vacuum.

It uses a refrigerant that boils below atmospheric pressure, so the low side runs under a vacuum.

R-11 and R-123 (HCFCs), and R-1233zd (a low-GWP HFO replacement).

The traditional low-pressure refrigerant in older centrifugal chillers; a CFC, now phased out.

The HCFC replacement for R-11 in low-pressure chillers; lower ODP but more toxic.

A near-zero-ODP, very-low-GWP HFO refrigerant used in newer low-pressure chillers.

25 mm Hg absolute.

A pressure measured from a perfect vacuum — not a reading on a standard vacuum gauge.

Low-pressure systems run under a vacuum, so the target is set from a perfect vacuum (25 mm Hg absolute).

Air and moisture leak IN, because the low side operates below atmospheric pressure.

Its low side is below atmospheric pressure, so higher outside pressure pushes air inward.

Gases like air and nitrogen that don't condense; they raise condensing pressure and cut efficiency.

Removes air and noncondensable gases from a low-pressure chiller while retaining the refrigerant.

An air leak letting noncondensables into the system — find and fix it.

They release far less refrigerant per unit of air purged than older designs.

A rupture disc, typically set around 15 psig.

Around 15 psig.

Dry nitrogen — inert, so it won't form a combustible mixture with the oil.

Oxygen can combine with refrigeration oil to form a combustible/explosive mixture.

It exceeds the ~15 psig rupture disc and would burst the disc.

R-123 has the lower ozone depletion potential.

Lower ODP than R-11, but higher toxicity — needs ventilation and exposure monitoring.

It raises condensing pressure and reduces system efficiency.

A centrifugal compressor.

Self-contained (active) recovery equipment designed for low-pressure work.

A large cooling machine using a centrifugal compressor — typically a low-pressure (Type III) appliance.

It boils below atmospheric pressure, so the system operates under a vacuum at normal temperatures.

Its low side sits in a vacuum during operation (below atmospheric pressure).

Air and moisture leaking IN (not refrigerant leaking out), because of the internal vacuum.

'mm Hg absolute' (25 mm Hg) — distinct from Type II's inches of mercury vacuum.

They raise condensing pressure and lower efficiency.

A purge unit running far more frequently than normal.

To stay under the rupture-disc setting and avoid bursting the disc.

More toxic — it requires greater attention to ventilation and exposure monitoring.

R-1233zd, a low-GWP, near-zero-ODP HFO.

Relieves excess pressure (around 15 psig) to protect the vessel from rupturing.

It can react with the refrigeration oil to form a combustible or explosive mixture.