EPA 609 Refrigerant Identification & Contaminated Refrigerant Handling — Questions and Answers
Question 1: Why should a technician use a refrigerant identifier before connecting recovery/recycling equipment to a vehicle?
- To measure the vehicle's cabin temperature
- To confirm the refrigerant type and purity so the recovery equipment and its tank are not contaminated (Correct answer)
- To find the exact location of a leak
- To work out how much oil is in the compressor
Correct answer: To confirm the refrigerant type and purity so the recovery equipment and its tank are not contaminated
An identifier checks what refrigerant is in the system and how pure it is. Recovering mixed or contaminated refrigerant into a dedicated recycling machine can contaminate the machine and its whole supply of refrigerant.
Question 2: If an identifier shows that a vehicle contains contaminated or unknown refrigerant, what should the technician do?
- Recover it with the shop's normal R-134a recycling machine
- Vent it, because contaminated refrigerant cannot be reused
- Recover it into a separate, dedicated container and send it for reclamation or proper disposal (Correct answer)
- Add fresh refrigerant to dilute the contamination
Correct answer: Recover it into a separate, dedicated container and send it for reclamation or proper disposal
Contaminated refrigerant still cannot legally be vented. It must go into a separate recovery unit or container used only for contaminated refrigerant, then be sent to a reclaimer or disposal facility.
Question 3: Why is hydrocarbon contamination found in an MVAC system an especially serious concern?
- Hydrocarbons are flammable and create a fire hazard (Correct answer)
- Hydrocarbons freeze the expansion valve
- Hydrocarbons make the refrigerant colorless
- Hydrocarbons are only a problem in R-12 systems
Correct answer: Hydrocarbons are flammable and create a fire hazard
Hydrocarbon refrigerants such as propane or butane blends are flammable. They are not approved for MVAC use, and they create fire and explosion risks for technicians and vehicle occupants.
Question 4: How can a technician check a refrigerant storage tank for excess air (non-condensable gases)?
- Weigh the tank and compare it with its tare weight
- Compare the tank pressure with the refrigerant's pressure-temperature chart at a stable ambient temperature (Correct answer)
- Shake the tank and listen
- Check the color of the tank valve
Correct answer: Compare the tank pressure with the refrigerant's pressure-temperature chart at a stable ambient temperature
At a stable temperature, pure refrigerant in a tank should be at the pressure listed on its PT chart. A pressure noticeably higher than the chart value shows that non-condensables such as air are present.
Question 5: What problem can leak sealant products in an MVAC system cause for the service shop?
- They improve recovery speed
- They can clog and damage recovery/recycling equipment (Correct answer)
- They turn R-134a into R-1234yf
- They have no effect on service equipment
Correct answer: They can clog and damage recovery/recycling equipment
Some sealants harden when exposed to air or moisture and can clog hoses, filters and internal parts of recovery/recycling machines. That is why sealant identification tools exist.
Question 6: Why does recovered refrigerant need to be identified even when the vehicle's label says R-134a?
- Labels are never put on vehicles
- The system may have been charged with a different or mixed refrigerant during earlier service (Correct answer)
- R-134a changes into a different chemical over time
- EPA requires a new label after every service
Correct answer: The system may have been charged with a different or mixed refrigerant during earlier service
Earlier service work, such as an improper top-off, a DIY can, or an unlabeled retrofit, may have left a different or mixed refrigerant in the system. The label only shows what should be there, not what is actually there.
