EPA Test (Section 608): Complete 2026 Study Guide Fast

The , officially known as the Section 608 Technician Certification exam, is a credential required by federal law for professionals who handle refrigerants. If you’re looking to start or advance your career in the HVAC industry, passing this test is a critical first step, as the certification is a mandatory requirement. This guide breaks down everything you need to know about the , from the core regulations to the specific techniques required for different types of equipment. You can dive deeper in our EPA certification articles.

What is EPA Section 608 Certification?

The Section 608 certification is a credential required by the U.S. Environmental Protection Agency (EPA) for any technician who maintains, services, repairs, or disposes of equipment that could release refrigerants into the atmosphere. Established under the Clean Air Act, this certification ensures that technicians handle these substances safely to protect the Earth’s ozone layer and climate.

Anyone who performs tasks like attaching gauges to an AC system, adding or removing refrigerant, or any other activity that could allow refrigerant to escape must be certified. The certification is broken down into four types:

• Type I: For servicing small appliances.

• Type II: For servicing high pressure systems.

• Type III: For servicing low pressure systems.

• Universal: A combination of Types I, II, and III.

Once you earn your certification by passing an approved , it never expires. You just need to keep proof of it for employers and any compliance checks.

The EPA Test Format: What to Expect

The Section 608 exam is a closed book, proctored test. This means you cannot use any notes or study materials during the exam, and an approved proctor must supervise you. Before the test begins, the proctor will verify your photo ID and make sure you are in a secure, quiet environment. During the exam, the proctor ensures there is no cheating and enforces any time limits.

The exam is designed to be a serious, professional licensing test. This format guarantees that every certified technician truly understands the material and will follow EPA regulations in the field.

Question Distribution and Passing Score

The Universal consists of 100 multiple choice questions, divided into four sections of 25 questions each:

1. Core

2. Type I

3. Type II

4. Type III

To pass and get certified, you must answer at least 18 out of 25 questions correctly in each section, which is a score of 72% (often rounded to 70%). The test is graded per section. This means you could pass the Core and Type II sections but fail Type I, in which case you would only be certified for Type II. To get Universal certification, you must pass all four sections. Guessing is not penalized, so it’s always better to answer every question.

With proper preparation, the is very achievable. Some online training programs report pass rates above 95% for their students.

Core Knowledge for the EPA Test

This section covers the foundational topics from the Core section of the exam that every technician must know.

Environmental Impact of Refrigerants

Refrigerants, especially older types, pose two major threats to the environment: ozone depletion and global warming. For the physics behind refrigerants and oils, explore our science fundamentals resources.

• Ozone Depletion: Older refrigerants like Chlorofluorocarbons (CFCs) and Hydrochlorofluorocarbons (HCFCs) contain chlorine. When released, this chlorine rises into the stratosphere and destroys the ozone molecules that protect us from the sun’s harmful UV radiation. A single chlorine atom can destroy tens of thousands of ozone molecules, contributing to the thinning of the ozone layer.

• Global Warming: Many refrigerants are also potent greenhouse gases. While newer Hydrofluorocarbons (HFCs) do not deplete the ozone layer, they have a high Global Warming Potential (GWP). For example, the common refrigerant R 134a has a GWP of 1,430, meaning it traps 1,430 times more heat than carbon dioxide over 100 years.

Because of these impacts, technicians must recover and recycle refrigerants instead of venting them into the atmosphere.

The Clean Air Act and Montreal Protocol

Two landmark regulations govern the handling of refrigerants: the Clean Air Act and the Montreal Protocol.

The Montreal Protocol is a global treaty signed in 1987 to phase out the production of ozone depleting substances worldwide. This agreement led to the successful phaseout of CFCs like R 12 by 1996 and HCFCs like R 22 by 2020 in the United States.

The U.S. Clean Air Act, specifically Title VI, puts these international goals into law. Section 608 of the act makes it illegal to knowingly vent refrigerants during service or disposal. Violating this rule can lead to massive fines, which can exceed $45,000 per day for each violation.

Section 608 Regulations at a Glance

The Section 608 regulations are the specific rules technicians must follow. Key rules include:

• Technician Certification: Anyone servicing AC and refrigeration equipment must be certified.

• No Venting: Intentionally releasing any refrigerant (CFC, HCFC, or HFC) is illegal.

• Sales Restrictions: The sale of refrigerants is restricted to certified technicians.

• Leak Repair: Owners of large systems (with over 50 pounds of refrigerant) must repair leaks that exceed a certain annual rate.

• Proper Disposal: All refrigerant must be recovered from equipment before it is scrapped.

Substitute Refrigerants and Oil Compatibility

As older refrigerants were phased out, new “substitute” refrigerants took their place. However, there is no such thing as a universal “drop in” replacement. Different refrigerants require different lubricating oils, and mixing them can cause catastrophic system failure.

For instance, older CFC and HCFC systems used mineral oil. Newer HFC refrigerants like R 134a are incompatible with mineral oil and require synthetic polyol ester (POE) oil instead. If you retrofit a system to use a new refrigerant, you must also ensure the oil is changed to a compatible type. Always consult the manufacturer’s guidelines.

The Basic Refrigeration Cycle

The refrigeration cycle is the process of moving heat from one place to another. It has four main components:

1. Evaporator: The indoor coil where low pressure liquid refrigerant absorbs heat and boils into a vapor. This is where cooling happens.

2. Compressor: The heart of the system. It sucks in the low pressure vapor and compresses it into a high pressure, high temperature vapor.

3. Condenser: The outdoor coil where the hot vapor releases its heat and condenses back into a liquid.

4. Expansion Device: This device creates a sudden pressure drop, turning the high pressure liquid into a cold, low pressure mix of liquid and vapor, ready to enter the evaporator again.

A key concept is the direct relationship between a refrigerant’s pressure and its boiling (saturation) temperature. Technicians use gauges to read system pressures, which tells them the temperature inside the coils.

Gauges and Leak Detection

A technician’s manifold gauge set is a critical diagnostic tool. It has a blue low pressure gauge and a red high pressure gauge that measure the suction and discharge pressures of the system. Abnormal readings, like low pressure on both sides, often indicate a refrigerant leak.

To find the exact location of a leak, technicians use several methods:

For step-by-step leak-check routines and PM checklists, see our HVAC maintenance guides.

• Electronic Leak Detectors: These “sniffers” are highly sensitive and can detect tiny amounts of refrigerant gas.

• Soap Bubble Solution: A simple and effective method where you apply a soap solution to a suspected joint. If a leak exists, it will form bubbles.

• Nitrogen Pressure Test: For empty systems, technicians pressurize them with dry nitrogen. A drop in pressure over time confirms a leak. Never use compressed air or pure oxygen to pressurize a system, as it can react with oil and cause an explosion.

• Visual Cues: A common sign of a refrigerant leak is an oily residue around a pipe fitting or valve.

The Three R’s: Recover, Recycle, and Reclaim

To prevent venting, technicians must handle used refrigerant according to the “Three R’s”.

• Recover: To remove refrigerant from a system and store it in an external container.

• Recycle: To clean refrigerant for reuse, typically by running it through filter driers. Recycled refrigerant can only be put back into equipment owned by the same person or company.

• Reclaim: To reprocess used refrigerant at a certified facility to meet the purity standards of new (virgin) product. Reclaimed refrigerant can be sold and used in any equipment.

Recovery and Dehydration Techniques

Proper recovery technique is essential for compliance and efficiency.

• Don’t Mix Refrigerants: Always use a clean, dedicated recovery cylinder for each type of refrigerant.

• Recover Liquid First: Removing the refrigerant as a liquid is much faster than recovering it as a vapor.

• Use Short Hoses: Use hoses that are as short and as wide as possible to speed up the recovery process.

• Dehydration (Evacuation): After repairs, you must use a vacuum pump to remove moisture and air from the system. Moisture can freeze and cause blockages or react with oil to form corrosive acids. A deep vacuum of 500 microns or lower is typically required.

Safety Procedures and PPE

Handling refrigerants involves serious risks. Always follow safety procedures.

• Wear PPE: At a minimum, wear safety glasses or goggles and gloves when working with refrigerants to protect against frostbite.

• Ensure Ventilation: Refrigerants are heavier than air and can displace oxygen, creating a suffocation hazard in enclosed spaces.

• Avoid Open Flames: When exposed to high heat, refrigerants can decompose into toxic substances like phosgene gas.

• Handle Cylinders Safely: Always store and transport cylinders in an upright, secured position. Never heat a cylinder with a flame or overfill it past 80% of its capacity.

Shipping and Labeling Cylinders

Refrigerant cylinders must be approved by the Department of Transportation (DOT) and properly labeled. Recovery cylinders are typically painted gray with a yellow top. When shipping used refrigerant, the cylinder must have a DOT classification tag (usually a green non flammable gas label) and clearly identify the type of refrigerant inside.

Certification Types: A Deeper Dive

While the Core section applies to everyone, the also has sections for different equipment types.

Type I: Small Appliances

This certification covers small appliances that are hermetically sealed and factory charged with five pounds or less of refrigerant, like refrigerators, window AC units, and dehumidifiers.

• Recovery Requirements: With modern equipment (made after Nov. 15, 1993), you must recover 90% of the refrigerant if the compressor is working, or 80% if it is not.

• Recovery Techniques: Since these units often lack service ports, technicians use piercing valves to access the refrigerant. If the compressor is broken, you may need to install valves on both the high and low sides of the system. Applying gentle heat to the compressor can help release trapped refrigerant.

• Safety: Many new small appliances use flammable hydrocarbon refrigerants like R 600a (isobutane). Always check the nameplate and take extreme care to avoid sparks or flames when servicing these units.

Type II: High Pressure Systems

Type II certification covers equipment using high pressure refrigerants like R 22 and R 410A. This includes residential central air conditioners, commercial rooftop units, and supermarket refrigeration. For deeper dives into design and maintenance, browse our commercial HVAC systems articles.

• Leak Detection: Besides using electronic sniffers, a key sign of a leak in a high pressure system is excessive superheat at the compressor or visible oil stains around fittings.

• Leak Repair Requirements: For systems with more than 50 pounds of refrigerant, owners must repair leaks that exceed the annual threshold. The threshold is 10% for comfort cooling and 20% for commercial refrigeration.

• Recovery Techniques: For large systems, use the “push pull” method to recover liquid refrigerant quickly. Using short, wide hoses and removing Schrader valve cores will also speed up the process.

• Recovery Requirements: With modern equipment, you must evacuate a system with less than 200 pounds of charge to 0 inches of mercury (Hg). For systems with 200 pounds or more, you must pull a vacuum of 10 inches of Hg.

• Machinery Room Safety: Large systems in equipment rooms must comply with ASHRAE Standard 15. This requires refrigerant leak detectors and an oxygen deprivation sensor, as any refrigerant can displace air and cause asphyxiation. The room must also have mechanical ventilation that activates when a leak is detected.

Type III: Low Pressure Systems

Type III certification is for servicing low pressure equipment, primarily centrifugal chillers that use refrigerants like R 123. These systems are unique because they operate in a vacuum. To review chiller internals and components, see our mechanical fundamentals.

• Leak Detection: The most common sign of a leak is air and moisture leaking into the system. This will cause the chiller’s purge unit to run excessively. To find the leak, you must first raise the system’s pressure, preferably by circulating hot water through the chiller, but never above 10 psig to avoid tripping the rupture disc.

• Leak Repair Requirements: The leak repair thresholds are the same as for Type II systems, typically 10% for comfort cooling chillers.

• Recovery Techniques: To recover refrigerant, circulate warm water through the chiller’s evaporator to raise the refrigerant’s pressure. It is crucial to keep the water moving to prevent it from freezing and bursting the tubes. After removing the liquid, you must continue to recover the vapor until you reach a deep vacuum of 25 mm Hg absolute (about 29 inches of Hg).

• Recharging Techniques: When recharging an evacuated chiller, you must introduce vapor first until the system pressure is above freezing to avoid damaging the evaporator tubes.

• Purge Units: Low pressure chillers have a purge unit to remove the air and non condensables that leak in. The purpose of the purge unit is to separate these gases from the refrigerant and vent them, keeping the system running efficiently.

Taking the EPA Test and Managing Your Certification

Proctors and Test Integrity

The EPA requires a proctored exam to maintain the integrity of the certification process. A proctor, sometimes called a Chief Examiner, is an individual approved by a certifying organization to administer the . They are responsible for verifying identity, monitoring the testing session, and ensuring all rules are followed.

Finding a Testing Location

Traditionally, technicians had to find a physical testing center to take their . Today, many accredited organizations offer fully online exams. This allows you to study and take the official proctored from home, on your own schedule.

Replacement Certification Cards

If you lose your certification card, you can request a replacement from the organization that administered your exam. Many, like SkillCat, offer an optional physical wallet card and provide a digital copy that you can always access.

Frequently Asked Questions

1. How hard is the EPA 608 test? The covers a lot of technical information, but it is not considered extremely difficult if you study properly. The passing score is 72% for each section. Using a good study guide and taking practice tests significantly increases your chances of passing on the first try.

2. How long does EPA 608 certification last? Your Section 608 certification is valid for life and does not need to be renewed.

3. Can I take the EPA test online? Yes. The EPA has approved several organizations, including SkillCat, to administer the official proctored Section 608 exam online. A proctor monitors you through your device’s camera.

4. What happens if I fail a section of the epa test? You only need to retake the section(s) you failed. For example, if you pass Core, Type I, and Type II but fail Type III, you will be certified for Types I and II. You can then retake just the Type III section later to earn your Universal certification. Most programs include at least one free retake.

5. Which EPA certification do I need for HVAC? For residential and commercial HVAC work, you will need Type II certification at a minimum. However, most employers prefer or require technicians to hold a Universal certification, as it allows you to legally work on any type of equipment you may encounter. If you’re new to the trade, start with our HVAC basics articles to build core skills alongside your certification prep.