EPA 608 Certification Study Guide (Core + Type I/II/III)

What You Need to Know (Scope + How the Exam Thinks)

You’re learning EPA Section 608 rules and best practices for handling refrigerants to prevent ozone depletion, reduce greenhouse emissions, and keep technicians safe. The test is mostly about:

• Legal requirements (venting prohibition, recovery, disposal, leak repair, recordkeeping basics)
• Recovery/evacuation levels by appliance category (Type I/II/III)
• Refrigerant science (ozone layer, ODP/GWP, blends, pressure/temperature basics)
• Safety (cylinders, non-condensables, dehydration, nitrogen, toxicity/asphyxiation)

Core idea to anchor everything:

• It’s illegal to intentionally vent refrigerants (CFC, HCFC, and most substitutes used as replacements, including many HFCs) during service, maintenance, repair, or disposal.
• Your job on the exam is usually to pick: (1) which “Type” applies, then (2) what procedure/evacuation level/rule applies.

The three “Types” in one line

• Type I: Small appliances (typically factory-sealed, $\le 5\,lb$ refrigerant)
• Type II: High-pressure & very-high-pressure appliances (everything else that isn’t Type I or III, excluding MVAC)
• Type III: Low-pressure appliances (typically chillers)

Reminder: Motor Vehicle A/C (MVAC) is Section 609, not 608 (though concepts overlap). EPA 608 Types don’t cover MVAC.

Step-by-Step Breakdown (How to Solve Most EPA 608 Questions)

1) Identify the appliance category (Type I, II, or III)

1. Is it a small appliance? Factory sealed, $\le 5\,lb$ charge (domestic fridge, window A/C, water cooler) → Type I
2. Is it a low-pressure chiller? Common refrigerants include R-11, R-123 → Type III
3. Otherwise, it’s Type II (split systems, package units, supermarket racks, most high-pressure systems)

2) Decide what the question is really asking

Most questions fall into one bucket:

• Recovery/evacuation level (how deep a vacuum / what pressure)
• Proper recovery procedure (liquid vs vapor, self-contained vs system-dependent)
• Leak rules (when you must repair, what counts as “major leak”, timelines)
• Refrigerant handling (blends, recovery cylinder rules, shipping/labeling)
• Safety (nitrogen use, dehydration, non-condensables, oxygen displacement)

3) Apply the rule with the correct units and reference point

• High-pressure evacuation levels are often given in inches of Hg vacuum or psig.
• Low-pressure evacuation levels are commonly in mm Hg absolute.

Exam trap: Don’t mix gauge pressure and absolute pressure.

4) Quick worked mini-examples (the pattern)

• Example pattern A (Type selection): “Domestic refrigerator” → small appliance $\le 5\,lb$ → Type I.
• Example pattern B (vacuum level): “Low-pressure chiller with R-123” → Type III → look for mm Hg absolute evacuation targets.
• Example pattern C (blend handling): “R-410A system low” → blend/near-azeotropic → charge as liquid.

Key Formulas, Rules & Facts

EPA definitions you must know

Ozone / environment essentials

• Ozone depletion: UV light breaks CFC/HCFC molecules → releases chlorine/bromine radicals → catalytically destroys ozone.
• ODP (Ozone Depletion Potential): CFCs high, HCFCs lower, HFCs ~0.
• GWP (Global Warming Potential): many HFCs high (even though ODP is zero).

Pressure: gauge vs absolute

• Relationship:

$psia = psig + 14.7\,psi$

• Atmospheric pressure is about:

$14.7\,psia$

• A “vacuum” reading in in Hg is referenced to atmosphere (common service gauges). Low-pressure rules often use mm Hg absolute.

REQUIRED recovery/evacuation levels (high-yield tables)

These are the classic EPA 608 exam tables tied to whether recovery equipment was manufactured before vs after $11/15/1993$.

Type I (Small appliances)

Type II (High-pressure & very-high-pressure appliances)

Type III (Low-pressure appliances)

Critical warning: Low-pressure numbers are in $mm\,Hg\,absolute$. Don’t answer in psig.

Leak repair rules (know the exam-style triggers)

• Leak repair requirements generally apply to appliances with $\ge 50\,lb$ refrigerant charge.
• “Leak rate” is typically expressed as percent per year.

Common exam thresholds (frequently taught in EPA 608 prep):

• Comfort cooling: $15\%$
• Commercial refrigeration: $35\%$
• Industrial process refrigeration: $35\%$

Also know:

• Leaks must be repaired when above the applicable threshold (with specific follow-up verification/testing expectations).
• Adding refrigerant to a system that has a leak may trigger requirements when thresholds are exceeded.

Regulations have been updated over time; for the test, use the thresholds your course materials emphasize. The values above are the most commonly tested set.

Refrigerant cylinders & fill rules

• Never mix refrigerants in the same recovery cylinder.
• Use proper recovery cylinders (commonly gray body with yellow top).
• Max fill: do not exceed $80\%$ of cylinder capacity by volume.

If the problem gives Tare Weight (TW) and Water Capacity (WC) and expects the common exam approximation:

$W_{\text{max gross}} = TW + 0.8\times WC$

If it instead gives “cylinder rated refrigerant capacity” (in $lb$ of refrigerant):

$W_{\text{max net}} = 0.8\times W_{\text{rated net}}$

Blends: zeotropic vs azeotropic (testable handling)

Exam trap: Many blend questions boil down to: charge as liquid to avoid fractionation.

Nitrogen and pressure testing

• Use dry nitrogen for pressure testing and sweeping.
• Never use oxygen or compressed air to pressure test a refrigeration system (explosion/combustion risk).
• If using trace refrigerant with nitrogen for leak checking, keep it minimal and follow safe practices.

Examples & Applications

Example 1: Pick the right certification Type

Question style: “You service a window A/C unit.”

• Window A/C is a small appliance (factory sealed, typically $\le 5\,lb$ charge).
• Answer: Type I.

Exam insight: If it’s a household-style sealed appliance, assume Type I unless told otherwise.

Example 2: Evacuation level for a large high-pressure system

Question style: “A high-pressure system has $250\,lb$ of refrigerant; recovery machine manufactured after $11/15/1993$. How far must you evacuate?”

• Type: II (high-pressure)
• Charge: $\ge 200\,lb$
• Equipment: after $11/15/1993$
• Answer: $10\,in\,Hg$ vacuum.

Example 3: Low-pressure chiller requirement

Question style: “Recovering R-123 from a low-pressure chiller using recovery equipment manufactured after $11/15/1993$.”

• Type: III
• Answer: $25\,mm\,Hg\,absolute$.

Exam insight: If you see R-11/R-123, think Type III and mm Hg absolute.

Example 4: Cylinder max fill calculation (common math question)

Given: Cylinder $TW = 28\,lb$, $WC = 47\,lb$. Find max gross weight (common exam method).

$W_{\text{max gross}} = 28 + 0.8\times 47$

$W_{\text{max gross}} = 28 + 37.6 = 65.6\,lb$

Answer: $65.6\,lb$ gross max on the scale.

Common Mistakes & Traps

1. Mistake: Mixing up Type I vs Type II
   You see “high-pressure refrigerant” and assume Type II, but the appliance is actually factory-sealed $\le 5\,lb$.
   Fix: Classify by appliance size/category, not just refrigerant pressure.

2. Mistake: Using the wrong units for Type III
   Students answer low-pressure evacuation in psig or in Hg vacuum when the question expects $mm\,Hg\,absolute$.
   Fix: For chillers/low-pressure: lock in absolute mm Hg values.

3. Mistake: Forgetting the $200\,lb$ breakpoint in Type II
   Evacuation targets differ for $<200\,lb$ vs $\ge 200\,lb$.
   Fix: Always ask: “Is it above $200\,lb$?” before choosing $0\,psig$ vs a vacuum requirement.

4. Mistake: Thinking HFCs are okay to vent because ODP is zero
   ODP $=0$ does not mean “legal to vent.” Venting prohibitions apply broadly.
   Fix: Treat venting as prohibited unless an explicit EPA exemption is stated.

5. Mistake: Charging blends as vapor
   Removing/adding vapor from zeotropic blends can change composition (fractionation).
   Fix: For blends, default to charging as liquid (using proper throttling to protect the compressor).

6. Mistake: Overfilling recovery cylinders
   Overfilled cylinders can hydrostatically expand and dangerously overpressure.
   Fix: Remember $80\%$ fill and weigh cylinders; use the $TW/WC$ method when asked.

7. Mistake: Using oxygen to “pressure test faster”
   Oxygen + oil/refrigerant can create an explosion hazard.
   Fix: Only use dry nitrogen (with proper regulators).

8. Mistake: Confusing recovery vs reclaim
   Students assume any cleaned refrigerant is “reclaimed.”
   Fix: Reclaim means processed to AHRI 700 purity standards (usually offsite).

Memory Aids & Quick Tricks

Quick Review Checklist

• Venting refrigerant is prohibited during service/disposal (know the general rule).
• You can classify appliances fast:
  • Type I: small appliance $\le 5\,lb$
  • Type II: high-pressure (most systems)
  • Type III: low-pressure chillers (R-11/R-123)
• Evacuation targets you must recall:
  • Type I: $4\,in\,Hg$ vacuum (post-$11/15/1993$ equipment) and system-dependent $80\%/90\%$ recovery rule
  • Type II: $0\,psig$ for $<200\,lb$; $10\,in\,Hg$ vacuum for $\ge 200\,lb$ (post-$11/15/1993$)
  • Type III: $25\,mm\,Hg\,absolute$ (post-$11/15/1993$)
• $80\%$ cylinder fill rule; don’t mix refrigerants; label cylinders.
• Use dry nitrogen for pressure testing; never oxygen.
• Blends: default to charge as liquid.
• Leak repair: know the $\ge 50\,lb$ trigger and the commonly tested leak-rate thresholds.

You’ve got this—if you can classify the system type quickly and recall the evacuation tables, you’ll pick up a huge chunk of points.