5 Core Section 608 Practice
Learn the certification scope, environmental principles, safety practices, refrigerant handling rules, and equipment requirements central to Section 608 work.
Certification and work scope
of the U.S. Clean Air Act establishes requirements for handling refrigerants in stationary air-conditioning and refrigeration equipment. A technician generally needs EPA certification to maintain, service, repair, or dispose of equipment when the work could reasonably be expected to release refrigerant. Certification is earned through an EPA-approved testing program and does not expire.
The Core exam covers general principles. Type I, II, and III exams cover additional equipment-specific material.
Refrigerants and ozone
Some refrigerants containing chlorine can deplete . Ultraviolet radiation breaks down these chemicals in the stratosphere and releases reactive chlorine, which destroys ozone. Ozone depletion allows more harmful ultraviolet radiation to reach Earth's surface.
also covers many refrigerant substitutes, including HFCs, even though they do not deplete ozone. Do not assume that a substitute is exempt; limited exceptions apply to certain specific substitutes and uses, so verify whether a particular refrigerant and application are exempt.
Refrigerant exposure and personal safety
Treat refrigerants as pressurized chemicals. Exposure can displace oxygen, affect the heart, or cause cold burns if liquid refrigerant contacts skin or eyes. Work in a well-ventilated area, avoid breathing refrigerant vapor, and use suitable gloves and eye protection.
For a major release in an enclosed space, do not enter without appropriate emergency training and respiratory protection.
Identify refrigerants and select equipment
Before connecting recovery equipment, identify the refrigerant, confirm that the equipment and cylinder are suitable for it, and inspect hoses and connections. Use recovery equipment certified for the intended application and follow its manufacturer’s instructions. Short, adequately sized hoses and maintained filters and equipment can improve recovery performance.
Use equipment rated for the refrigerant and pressures involved. Connect and disconnect carefully to limit refrigerant loss, and use low-loss fittings where appropriate. Applicable recovery requirements depend on the appliance category and circumstances.
Recovery, recycling, and reclamation
, , and describe different levels of refrigerant handling:
: Remove refrigerant from an appliance and store it in an external container. It need not be cleaned or tested.
: Clean recovered refrigerant for reuse, generally in equipment belonging to the same owner. Recycling does not bring the refrigerant to the purity standard required for reclamation.
: Reprocess refrigerant to the applicable purity standard and verify that it meets that standard, typically through an EPA-certified reclaimer.
Refrigerant removed from an appliance should be kept separate from other refrigerants. Mixing can contaminate the contents and make them difficult or impossible to reuse. Used refrigerant generally must be reclaimed before it is sold to a new owner.
Venting rules
generally prohibits intentionally venting ozone-depleting refrigerants and their substitutes while maintaining, servicing, repairing, or disposing of air-conditioning or refrigeration equipment. A narrow allowance applies to de minimis releases made during good-faith efforts to recapture refrigerant, such as small releases when connecting or disconnecting hoses. This allowance does not permit deliberate discharge.
Limited exceptions apply to certain specific substitutes and uses. Verify whether a particular refrigerant and application are exempt rather than assuming that they are.
after repairs
After repairs, evacuate the system as required to remove air and moisture before charging. Air and moisture can impair operation and contribute to corrosion, ice formation, or elevated operating pressures. EPA levels vary with appliance type, charge, and equipment age; consult the applicable requirements instead of assuming one vacuum target applies to every system.
Do not use refrigerant as a pressure-test gas or release refrigerant to clear a line.
Pressure testing
Use dry nitrogen to pressure-test a system, with a regulator and suitable pressure-relief protection. Never exceed the equipment manufacturer’s pressure limits. Do not use oxygen or compressed air: either can create a fire or explosion hazard when mixed with refrigerant oil.
Do not use refrigerant vapor released from another system for pressure testing.
Cylinder handling
Use approved, refillable recovery cylinders for recovered refrigerant. Never refill disposable cylinders. Do not fill a beyond 80% of its rated capacity by weight; refrigerant expands as it warms, and an overfilled cylinder can develop dangerously high pressure.
Use the correct cylinder, do not exceed its marked fill limit, and label or otherwise identify its contents as required. Secure cylinders upright and protect them from heat and physical damage. Follow cylinder markings and applicable transport rules.
Refrigerant identity and sales
Read the appliance label and verify the refrigerant before recovery. Never assume that two refrigerants are interchangeable or that a substitute is a drop-in replacement: refrigerants may require different oils, components, and service procedures.
Refrigerant sales are generally restricted to appropriately certified technicians or their employers, subject to limited exceptions. Do not sell used refrigerant to a new owner unless it has been reclaimed as required.