The EPA Section 608 Certification Structure
Under Section 608 of the Clean Air Act, any technician who maintains, services, repairs, or disposes of equipment containing regulated refrigerants must hold an EPA Section 608 certification. The examination evaluates a technician's understanding of stratospheric ozone depletion, refrigerant containment, recovery protocols, evacuation standards, and federal recordkeeping.
The EPA Section 608 Universal exam is structured into four distinct modules of 25 multiple-choice questions each (100 questions total). A technician must achieve at least 70% (18 correct out of 25) on the Core section plus each individual type to earn that rating. Passing Core plus all three types confers the Universal Certification, permitting work on all HVAC/R equipment.
Test your knowledge with our free timed EPA 608 simulator or study the numbers with the EPA 608 cheat sheet.
The Four Certification Types
| Certification Level | Equipment Scope | Passing Requirement |
|---|---|---|
| Core | Ozone depletion chemistry, Clean Air Act regulations, Montreal Protocol, AIM Act, cylinder safety, and shipping. | 70% (18/25). Mandatory prerequisite for all other types. |
| Type I | Small appliances manufactured, charged, and hermetically sealed with 5 lbs or less of refrigerant (domestic refrigerators, freezers, room air conditioners, dehumidifiers). | 70% (18/25). |
| Type II | Medium, high, and very high-pressure appliances (split air conditioning systems, commercial refrigeration units, heat pumps, rooftop chillers). | 70% (18/25). |
| Type III | Low-pressure appliances operating in vacuum conditions (centrifugal chillers using R-11, R-123). | 70% (18/25). |
| Universal | Certified across Core, Type I, Type II, and Type III. Qualified for any refrigeration equipment. | Pass Core and all three types. |
Mandatory Evacuation Levels (Inches of Mercury Vacuum)
Before opening an HVAC system for major repairs (replacement of compressor, condenser, evaporator coil, or auxiliary heat exchanger), technicians must evacuate refrigerant down to mandatory vacuum levels to minimize atmospheric venting.
| Appliance Category & Charge | Equipment Made Before Nov 15, 1993 | Equipment Made On/After Nov 15, 1993 |
|---|---|---|
| Very High-Pressure Appliance (R-13, R-23, R-503) | 0.0 in. Hg (0 psig) | 0.0 in. Hg (0 psig) |
| High-Pressure Appliance (< 200 lbs) (R-22, R-410A, R-134a) | 0.0 in. Hg (0 psig) | 10 in. Hg vacuum |
| High-Pressure Appliance (≥ 200 lbs) (Commercial systems / Large chillers) | 4 in. Hg vacuum | 15 in. Hg vacuum |
| Medium-Pressure Appliance | 4 in. Hg vacuum | 10 in. Hg vacuum |
| Low-Pressure Appliance (R-11, R-123 chillers) | 25 in. Hg vacuum (25 mm Hg absolute) | 25 mm Hg absolute (approx. 29 in. Hg vacuum) |
Mandatory Leak Repair Thresholds (≥ 50 lbs Charge)
For systems containing 50 pounds or more of regulated ozone-depleting (ODS) or non-exempt substitute refrigerant, the EPA mandates strict annual leak repair trigger rates under 40 CFR § 82.156:
| Appliance Category | Annual Leak Rate Trigger | Mandatory Repair Window | Verification Requirements |
|---|---|---|---|
| Comfort Cooling (Office chillers, residential central AC) | 10% per year | 30 days from leak discovery | Initial verification test before recharging + Follow-up verification test within 30 days of normal operation. |
| Commercial Refrigeration (Supermarket rack systems, cold warehouses) | 20% per year | 30 days from leak discovery | Initial verification test + Follow-up verification test within 30 days. |
| Industrial Process Refrigeration (IPR) (Chemical, pharmaceutical, manufacturing) | 30% per year | 30 days (or 120-day plan if plant shutdown required) | Initial verification test + Follow-up verification test within 30 days. |
Recovery Cylinder Specifications & Safety
Refrigerant recovery cylinders differ fundamentally from disposable manufacturer cylinders:
- Color Code Standard: An EPA-approved recovery cylinder must have a gray body with a yellow top (shoulder and collar). Disposable DOT-39 cylinders are color-coded by virgin refrigerant type and must never be refilled.
- 80% Maximum Liquid Fill (by Weight): Recovery cylinders must never be filled beyond 80% of their total capacity by weight to allow for thermal expansion when heated. The maximum gross weight formula is:
Maximum Gross Weight = (0.80 × Water Capacity × Specific Gravity) + Tare Weight. - Hydrostatic Testing: Recovery cylinders must be hydrostatically tested and recertified every 5 years.
- Safety Relief Device: Low-pressure centrifugal systems employ a rupture disk rated at 15 psig, which vents outside the machinery room.
Refrigerant Chemistry & Environmental Agreements
| Refrigerant Class | Ozone Depletion Potential (ODP) | Global Warming Potential (GWP) | Common Examples | Phaseout Status |
|---|---|---|---|---|
| CFCs (Chlorofluorocarbons) | High (1.0) | Very High (4,000–10,000) | R-11, R-12, R-115, R-500 | Production banned Dec 31, 1995 (Montreal Protocol). |
| HCFCs (Hydrochlorofluorocarbons) | Moderate (0.05) | High (1,800) | R-22, R-123 | Production & import phased out Jan 1, 2020. Existing equipment serviced with recovered stock only. |
| HFCs (Hydrofluorocarbons) | 0.0 (Zero ODP) | High (1,400–4,000) | R-134a, R-410A, R-404A | Zero ozone impact, but phased down under the 2020 AIM Act / Kigali Amendment due to global warming. |
| HFOs & Naturals | 0.0 (Zero ODP) | Ultra-Low (<1) | R-1234yf, R-290 (Propane), R-744 (CO2) | Modern eco-friendly replacements. |
Frequently Asked Questions
What is the passing score for the EPA Section 608 Universal exam?
Technicians must score at least 70% (18 out of 25 questions correct) on the Core section and on each individual technical section (Type I, Type II, and Type III).
What are the leak rate trigger thresholds under Section 608?
For systems with 50 lbs or more of refrigerant, the annual leak trigger rates are 10% for comfort cooling, 20% for commercial refrigeration, and 30% for industrial process refrigeration.
What color is an EPA recovery cylinder?
Refillable recovery cylinders must have a gray body with a yellow top and shoulder.
What is the maximum liquid fill limit for a refrigerant cylinder?
Cylinders must never be filled above 80% of their rated capacity by weight at 77°F to prevent hydraulic pressure rupture from temperature fluctuations.
Sources
- U.S. Environmental Protection Agency (EPA) — Section 608 of the Clean Air Act: Stationary Refrigeration and Air Conditioning Regulations (40 CFR Part 82, Subpart F).
- EPA Technician Certification Program — Test Topic Content Outlines for Core, Type I, Type II, and Type III.
- QuizCram Technical Editorial Review Board — Verified October 27, 2026 against current EPA 40 CFR § 82 guidelines.
