EPA Practice Test (608 Core) 3 — Questions and Answers
Question 1: What is the primary environmental consequence of refrigerant CFCs and HCFCs reaching the stratosphere?
- They increase acid rain by reacting with nitrogen oxides
- They catalytically destroy ozone molecules, thinning the protective ozone layer (Correct answer)
- They create smog by reacting with ground-level ozone
- They absorb solar radiation, directly increasing surface temperatures
Correct answer: They catalytically destroy ozone molecules, thinning the protective ozone layer
CFCs and HCFCs release chlorine atoms when exposed to UV radiation in the stratosphere. Each chlorine atom catalytically destroys thousands of ozone molecules (O3 → O2 + O) through a chain reaction. Thinning of the ozone layer allows more UV-B radiation to reach Earth's surface, increasing skin cancer rates, cataracts, and damage to ecosystems and marine phytoplankton.
Question 2: How does a refrigerant's "vapor pressure" affect the type of recovery equipment needed?
- Higher vapor pressure refrigerants require vacuum pumps; lower vapor pressure refrigerants only need gravity recovery
- High vapor pressure (high-pressure) refrigerants require compressor-based recovery; very low-pressure refrigerants may use heat and temperature differential methods (Correct answer)
- Vapor pressure has no effect on recovery equipment selection
- All refrigerants use identical recovery equipment regardless of vapor pressure
Correct answer: High vapor pressure (high-pressure) refrigerants require compressor-based recovery; very low-pressure refrigerants may use heat and temperature differential methods
Refrigerant vapor pressure at operating temperatures determines the recovery approach. High-pressure refrigerants (R-22, R-410A) have significant vapor pressure at room temperature, requiring compressor-based recovery machines to capture them efficiently. Low-pressure refrigerants (R-11, R-123) have very low vapor pressures and can sometimes be recovered using heat applied to the evaporator to drive refrigerant toward the recovery cylinder. Equipment selection must match refrigerant characteristics.
Question 3: Why is it important to never mix different refrigerants in the same recovery cylinder?
- Mixed refrigerants can cause cylinder over-pressurization leading to explosion
- Mixed refrigerants create a non-reclaimable contaminated blend that must be destroyed (Correct answer)
- Different refrigerants react chemically to produce toxic byproducts in cylinders
- Mixed refrigerants cannot be reused and must be vented to atmosphere
Correct answer: Mixed refrigerants create a non-reclaimable contaminated blend that must be destroyed
When different refrigerants are mixed in a recovery cylinder, the result is a contaminated blend that cannot be separated by standard recycling methods. The only option is to send the contaminated cylinder to a reclaimer who must destroy it, as the mixed refrigerant cannot be restored to a usable pure or certified blend. This wastes refrigerant and incurs disposal costs. Always use separate, clearly labeled cylinders for each refrigerant type.
Question 4: A manifold gauge set's high-side (red) hose is connected to which service port on a refrigeration system?
- The suction service valve on the low-pressure side
- The discharge service valve or liquid line on the high-pressure side (Correct answer)
- Either side — the gauge set compensates for pressure direction
- The crankcase oil charging port
Correct answer: The discharge service valve or liquid line on the high-pressure side
On a standard manifold gauge set, the red (high-side) hose connects to the high-pressure side of the system — typically the discharge service valve on the compressor outlet or the liquid line service valve. The blue (low-side) hose connects to the suction (low-pressure) side. The yellow center hose connects to recovery cylinders, vacuum pumps, or refrigerant supply cylinders. Connecting incorrectly could send high-pressure refrigerant where it should not go.
Question 5: When must an appliance owner notify the EPA of a leak in a system with over 50 lbs of refrigerant?
- Immediately when the leak is discovered
- Within 30 days if the leak has not been repaired after exceeding threshold for more than 30 days (Correct answer)
- Annually through EPA's online reporting system
- No notification to EPA is required — records must only be kept on-site
Correct answer: Within 30 days if the leak has not been repaired after exceeding threshold for more than 30 days
Under EPA Section 608 regulations, appliance owners whose systems exceed the applicable leak rate threshold must repair the leak within 30 days. If the leak cannot be repaired within 30 days and the owner cannot prepare a retrofit/retirement plan, they must notify the EPA within the same 30-day window. For industrial process refrigeration, a one-time 120-day extension may be sought under specific conditions.
Question 6: Which statement is TRUE regarding the Section 608 venting prohibition for substitute refrigerants?
- Only CFCs and HCFCs are subject to the venting prohibition; HFCs may be vented
- HFCs used as refrigerant substitutes are also subject to the EPA's venting prohibition under Section 608 (Correct answer)
- The venting prohibition only applies to refrigerants above 50 lbs per system
- The venting prohibition does not apply to refrigerants with a GWP below 1,000
Correct answer: HFCs used as refrigerant substitutes are also subject to the EPA's venting prohibition under Section 608
The EPA extended the Section 608 venting prohibition to HFC refrigerants used as substitutes for ozone-depleting substances. This means R-410A, R-134a, R-404A, and other HFCs are all subject to the prohibition against intentional venting to the atmosphere. The prohibition applies to all refrigerants used in equipment covered by Section 608, regardless of ODP — it is now driven by both ozone protection and climate concerns.
EPA Practice Test (608 Core) 3
What is the primary environmental consequence of refrigerant CFCs and HCFCs reaching the stratosphere?