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EPA 608 NEC 2023

EPA 608 Core Exam Practice Test 3

Free Online EPA 608 Core Exam Practice Test 3This free 25-question practice test covers the EPA 608 Core exam section — required for all refrigerant technicians. Topics include refrigerant recycling equipment types, R-12 retrofits, recovery cylinder rules, manifold gauge color codes, leak detection methods, nitrogen flushing, refrigerant classification (CFC/HCFC/HFC), POE oil moisture limits, blend types (binary/ternary), pressure-temperature relationships, and vacuum measurement in microns.

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The EPA 608 certification is required by law for any technician who purchases or handles refrigerants. It covers safe handling, leak detection, recovery, and environmental regulations.

Type I covers small appliances (≤5 lbs refrigerant), Type II covers high-pressure systems, Type III covers low-pressure systems, and Universal covers all three. Most HVAC technicians pursue Universal certification.

You must score at least 70% on each section of the exam. The Universal exam has four parts: core, Type I, Type II, and Type III.

Key facts for this test: Recycling machines are SELF-CONTAINED (not system-dependent). The yellow center port on a manifold gauge connects to recovery/vacuum/refrigerant supply. A halide torch detects CFC/HCFC leaks only — electronic detectors work for HFCs too. Nitrogen is safe for flushing; NEVER use oxygen (fire hazard). CFC has the highest ODP. R-134a is an HFC — no chlorine, zero ODP. Recovery cylinders must be hydrostatically tested every 5 YEARS. Higher pressure = higher boiling point. Proper deep vacuum = 500 microns or less.

25

Questions

45 min

Time

70%

Pass

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Student Reviews 5.0 / 5 · 1 review

K

Kira Vasquez

I needed the 608 for a new HVAC position and had maybe three weeks to study. Between the core and Type I/II tests on this site I felt well prepared. Suprisingly good explanations for a free resource.

EPA 608 Core Exam Practice Test 3 — Question List

Question 1: All refrigerant recycling machines are ___________.

system dependent recycling equipment
Self contained recycling equipment

Question 2: which of the following is the leading replacement option for retrofitting R- 12 refrigeration systems?

R-134a
R-22
R 234
R 44

Question 3: Before disposal, a refrigerant container (recovery cylinder) must be brought to a pressure of ___________.

Zero psig
Zero psia
Zero bars
Zero kpa

Question 4: At what period the reusable cylinders should be hydrostatically treated for strength check?

Five years
Four years
Three years
Six years

Question 5: What is the color code for central port of manifold gauge?

Red
Blue
Yellow
White

Question 6: which of the following is the most effective method for small leaks?

halide torch
pulling vacuum on system
charging with dry nitrogen
pumping high pressure

Question 7: After recovering refrigerant from a system which may be used to flush debris out of system?

Nitrogen
CO<sub>2</sub>
O<sub>2</sub>
helium

Question 8: What does CFC stands for?

Chlorofluorocarbon
Chlorofluorochlorine
carbonfluorochlorine

Question 9: ___________ refrigerants have the highest ozone depletion potential (ODP).

HCFC
CFC
HFC

Question 10: Which of the following refrigerants is NOT classified as an HCFC?

R-134a
R-22
R-123
R-11

Question 11: What is the water saturation limit of POE ester oil?

25 ppm
2500 ppm
6,500 ppm
10,000 ppm

Question 12: Refrigerant blends made up of exactly TWO different refrigerants are called ___________.

binary blends
ternary blends
multi blends

Question 13: If the pressure on a liquid is increased, the boiling point of the liquid ___________.

decreases
increases
Remains same

Question 14: When measuring vacuum depth, one micron equals ___________ of a millimeter.

1/10 th
1/100 th
1/1000 th
1/10000th

Question 15: Standard manifold gauge sets cannot accurately measure deep vacuum. Which tool is required to verify that a system has reached proper vacuum depth in microns?

Standard manifold gauge set
Electronic micron gauge
Clamp-on ammeter
Refrigerant scale

Question 16: For most residential and commercial refrigerant systems, the system must be evacuated to _____ microns or below before charging with refrigerant.

25,000 microns
5,000 microns
500 microns
50 microns

Question 17: A refrigerant blend made up of THREE different refrigerants mixed together is called a ___________.

Binary blend
Ternary blend
Azeotropic blend
Multi-phase blend

Question 18: When moisture enters a refrigerant system, it reacts with the refrigerant and oil to form _____, which destroys compressor windings and metal parts.

Water vapor
Acid
Carbon dioxide
Nitrogen oxide

Question 19: In the ASHRAE refrigerant safety classification system, a refrigerant labeled "A1" is classified as ___________.

Higher toxicity and highly flammable
Lower toxicity and non-flammable
Lower toxicity and mildly flammable
Higher toxicity and non-flammable

Question 20: A technician uses a pressure-temperature (P-T) chart to find ___________.

The GWP and ODP values of a refrigerant
The saturation temperature of a refrigerant at a given pressure
The maximum fill weight for a recovery cylinder
The viscosity of the correct oil for each refrigerant

Question 21: Any time a refrigerant system is opened for service or repair, which component should ALWAYS be replaced before the system is evacuated and recharged?

Compressor
Filter drier
Condenser coil
Service valve cores

Question 22: An "azeotropic" refrigerant blend behaves like a single refrigerant because it has ___________.

Very high global warming potential
No temperature glide and does not fractionate
Zero ozone depletion potential
More than three refrigerant components

Question 23: Which document, required to be readily available in the workplace, contains safety information, first aid procedures, storage guidelines, and handling precautions for refrigerants?

EPA 608 certification card
Safety Data Sheet (SDS)
DOT hazmat placard
AHRI Standard 700 certificate

Question 24: To prevent dangerous overpressure from temperature-related expansion, a recovery cylinder must NEVER be filled beyond _____ percent of its water capacity.

60 percent
80 percent
90 percent
100 percent

Question 25: True or False: Refrigerant in containers of 2 pounds or less may be purchased without EPA 608 certification.

True
False

Study Tip: The EPA 608 exam is closed book. Memorize: recovery is required before opening any refrigerant system. Venting refrigerant is illegal. Know the ODP and GWP values for R-22, R-410A, R-134a, R-32, and R-454B.

EXAM CARD EPA 608

Questions25

Time limit45 min

Pass score70%

Code editionNEC 2023

DifficultyIntermediate

Last reviewedJun 2026

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Source: EPA Section 608 (40 CFR Part 82)