Under 40 CFR 82.154(a), which refrigerant in a household refrigerator is exempt from the venting prohibition?
Isobutane, R-600a. Section 82.154(a) exempts it in household refrigerators, freezers and combination units, from both the venting prohibition and the rest of Subpart F. R-12, R-22 and R-134a must still be recovered.
- R-134a
- R-12
- Isobutane (R-600a)Correct answer
- R-22
Why “Isobutane (R-600a)” is correct
Section 82.154(a)(1) exempts isobutane (R-600a) in household refrigerators, freezers and combination units from the venting prohibition and the rest of Subpart F. R-12, R-22 and R-134a in the same appliance must be recovered.
Source: 40 CFR 82.154(a)
Why the other answers are wrong
- R-134a — R-134a is a non-exempt HFC substitute, so venting it is prohibited.
- R-12 — R-12 is a CFC; venting it has always been prohibited.
- R-22 — R-22 is an HCFC and may not be vented.
The source, word for word
Notwithstanding any other provision of this subpart, the following substitutes in the following end-uses are exempt from this prohibition and from the requirements of this subpart:
Isobutane (R-600a) in retail food refrigerators and freezers (stand-alone units only); household refrigerators, freezers, and combination refrigerators and freezers; and vending machines;
Exempt in household refrigerators and freezers
An exemption is tied to the substance and the end-use together. Three listed hydrocarbon substitutes cover household refrigerators and freezers.
| Refrigerant | Status |
|---|---|
| Propane (R-290) | Exempt |
| Isobutane (R-600a) | Exempt |
| R-441A | Exempt |
| R-134a | Not exempt, must be recovered |
| R-22, R-12 | Not exempt, must be recovered |
Check the nameplate
The exemption follows the refrigerant in that appliance, so read the label before deciding how to handle it. The same substance outside the listed end-uses isn't exempt. What may be released gives the wider list.
Keep practicing
- What may be released without breaking the venting ban
- What counts as a small appliance
- Refrigerant types: CFC, HCFC, HFC and HFO
- EPA 608 Type 1 practice test
- EPA 608 Type 1 mock exam
Unofficial, not affiliated with the EPA or any EPA-approved certifying organization. Questions are original practice written from public EPA material, not real exam questions.