2025/2026
EPA 608 Universal Exam
What are two factors that, if present, are most likely to lead to an explosion with
hydrocarbon refrigerants?
CORRECT ANSWER: A sufficient concentration of the refrigeration in the space
and an ignition source
An appliance normally containing more than 50 pounds of R-22 refrigerant was
found to have a 35% annual leak rate. After the repair, how many successful
verification tests are required?
CORRECT ANSWER: Two. Performed before the appliance is recharged
All appliances must be equipped with a service aperture or process stub which is
used when adding or removing refrigerant from the appliance. What is typically used
on small appliances?
CORRECT ANSWER: A straight piece of tubing that is entered using a piercing
access valve. Process Tube
What is the primary purpose of a purge unit on a low-pressure chiller?
CORRECT ANSWER: Remove non-condensable from the system
Which of the following are recommended safe work practices when recovering
refrigerants?
CORRECT ANSWER: Wear safety eyewear and butyl-lined gloves when
connecting/disconnecting hoses
What is the state of the refrigerant leaving the receiver in a refrigeration system?
CORRECT ANSWER: High pressure liquid
Which of the following repairs would always be considered "major" under EPA's
regulations?
CORRECT ANSWER: Replacement of an evaporator coil
On low-pressure chillers, moisture most frequently enters the refrigeration system
through:
CORRECT ANSWER: Leaks from areas with gaskets or fittings
How would you remove moisture from refrigerant in a system?
CORRECT ANSWER: Use a filter drier
Where does refrigerant go after it leaves the purge unit of a low-pressure centrifugal
system?
CORRECT ANSWER: The evaporator
Which refrigerants can be mixed in an appliance?
CORRECT ANSWER: Refrigerants cannot be mixed
1|P ag e
, 2025/2026
What gas should be used to leak check a system designed for use with R-410A that
has been opened for a major system repair?
CORRECT ANSWER: Pressurized nitrogen
What is the term for removing refrigerant in any condition from a system and storing
it in an external container without necessarily testing or processing it in any way?
CORRECT ANSWER: Recovery
What is meant by the term "high efficiency purge unit"?
CORRECT ANSWER: Purge units that discharge a low percentage of refrigerant
with the air they remove
Before beginning a refrigerant recovery procedure, it is ALWAYS necessary to:
CORRECT ANSWER: know the type of refrigerant in the system
Which of the following gases is used as the baseline measurement for global
warming potential?
CORRECT ANSWER: Carbon Dioxide
Which hydrocarbon refrigerant is approved for retrofit into existing household
refrigerators?
CORRECT ANSWER: HC R-600a 2 ounces or less
Recovered refrigerant may contain which of the following impurities?
CORRECT ANSWER: Acids, moisture, and oil
A hydrostatic tube test kit will
CORRECT ANSWER: determine if a lube leaks
When installing any type of access fitting onto a sealed system:
CORRECT ANSWER: the fitting should be leak tested before proceeding with
recovery
A chiller with a charge of 200 pounds of an ozone-depleting refrigerant has passed
the initial verification leak test. When must a follow-up verification test be conducted?
CORRECT ANSWER: Within 10 days
Why are some hydrofluoroolefin (HFO) refrigerants classified as "A2L"?
CORRECT ANSWER: They are less flammable than hydrocarbon refrigerants, but
most are still mildly flammable
To determine if the system is leaking more than the allowed rate, the EPA allows the
use of which one of the following methods to determine the full charge?
CORRECT ANSWER: Use of calculations based on component and pipe sizes
When could a reciprocating compressor be damaged if energized?
CORRECT ANSWER: When the discharge service valve is closed
Which of the following are included in EPA's definition of a "small appliance"?
2|P ag e
EPA 608 Universal Exam
What are two factors that, if present, are most likely to lead to an explosion with
hydrocarbon refrigerants?
CORRECT ANSWER: A sufficient concentration of the refrigeration in the space
and an ignition source
An appliance normally containing more than 50 pounds of R-22 refrigerant was
found to have a 35% annual leak rate. After the repair, how many successful
verification tests are required?
CORRECT ANSWER: Two. Performed before the appliance is recharged
All appliances must be equipped with a service aperture or process stub which is
used when adding or removing refrigerant from the appliance. What is typically used
on small appliances?
CORRECT ANSWER: A straight piece of tubing that is entered using a piercing
access valve. Process Tube
What is the primary purpose of a purge unit on a low-pressure chiller?
CORRECT ANSWER: Remove non-condensable from the system
Which of the following are recommended safe work practices when recovering
refrigerants?
CORRECT ANSWER: Wear safety eyewear and butyl-lined gloves when
connecting/disconnecting hoses
What is the state of the refrigerant leaving the receiver in a refrigeration system?
CORRECT ANSWER: High pressure liquid
Which of the following repairs would always be considered "major" under EPA's
regulations?
CORRECT ANSWER: Replacement of an evaporator coil
On low-pressure chillers, moisture most frequently enters the refrigeration system
through:
CORRECT ANSWER: Leaks from areas with gaskets or fittings
How would you remove moisture from refrigerant in a system?
CORRECT ANSWER: Use a filter drier
Where does refrigerant go after it leaves the purge unit of a low-pressure centrifugal
system?
CORRECT ANSWER: The evaporator
Which refrigerants can be mixed in an appliance?
CORRECT ANSWER: Refrigerants cannot be mixed
1|P ag e
, 2025/2026
What gas should be used to leak check a system designed for use with R-410A that
has been opened for a major system repair?
CORRECT ANSWER: Pressurized nitrogen
What is the term for removing refrigerant in any condition from a system and storing
it in an external container without necessarily testing or processing it in any way?
CORRECT ANSWER: Recovery
What is meant by the term "high efficiency purge unit"?
CORRECT ANSWER: Purge units that discharge a low percentage of refrigerant
with the air they remove
Before beginning a refrigerant recovery procedure, it is ALWAYS necessary to:
CORRECT ANSWER: know the type of refrigerant in the system
Which of the following gases is used as the baseline measurement for global
warming potential?
CORRECT ANSWER: Carbon Dioxide
Which hydrocarbon refrigerant is approved for retrofit into existing household
refrigerators?
CORRECT ANSWER: HC R-600a 2 ounces or less
Recovered refrigerant may contain which of the following impurities?
CORRECT ANSWER: Acids, moisture, and oil
A hydrostatic tube test kit will
CORRECT ANSWER: determine if a lube leaks
When installing any type of access fitting onto a sealed system:
CORRECT ANSWER: the fitting should be leak tested before proceeding with
recovery
A chiller with a charge of 200 pounds of an ozone-depleting refrigerant has passed
the initial verification leak test. When must a follow-up verification test be conducted?
CORRECT ANSWER: Within 10 days
Why are some hydrofluoroolefin (HFO) refrigerants classified as "A2L"?
CORRECT ANSWER: They are less flammable than hydrocarbon refrigerants, but
most are still mildly flammable
To determine if the system is leaking more than the allowed rate, the EPA allows the
use of which one of the following methods to determine the full charge?
CORRECT ANSWER: Use of calculations based on component and pipe sizes
When could a reciprocating compressor be damaged if energized?
CORRECT ANSWER: When the discharge service valve is closed
Which of the following are included in EPA's definition of a "small appliance"?
2|P ag e
