R-32 Refrigerant: What It Is, Who Can Buy It, and What Changes on the Job

R-32 (difluoromethane) is a single-compound HFC refrigerant with a GWP of 675, classed A2L (mildly flammable) by ASHRAE. EPA lists it as acceptable, subject to use conditions, in new residential and light commercial air conditioners and heat pumps. It is not banned. It may be sold only to Section 608 certified technicians, and it is not a retrofit option for R-410A systems.

Most of what turns up when you search for R-32 is written for somebody else. Manufacturer pages sell it to homeowners, forum threads ask where to buy it, and online listings sell 22-ounce cans with no mention of who is allowed to buy them. What a technician actually needs is narrower: what the refrigerant is, which rules apply to it, and what is different when you hook gauges to it. That is what this article covers, and it separates what the regulation requires from what is simply good practice.

What is R-32 refrigerant?

R-32 is difluoromethane, CH₂F₂. It is a hydrofluorocarbon, so it contains no chlorine and has zero ozone depletion potential. It is also a pure compound rather than a blend. That matters on the job more than anything else about it.

It is not new. R-32 has been a component of R-410A all along: R-410A is a 50/50 blend of R-32 and R-125. Using R-32 alone removes the R-125, which carries most of R-410A's global warming potential, and that is why R-32 clears limits R-410A cannot.

Property	R-32	R-410A
Composition	Single compound (difluoromethane)	50% R-32 / 50% R-125
Temperature glide	None	Near-azeotropic, negligible
100-year GWP (EPA)	675	2,088
ASHRAE 34 safety group	A2L — mildly flammable	A1 — non-flammable
Pressure vs R-410A at 40 °F saturation	About 121 psig	About 118 psig
Allowed in new US residential AC	Yes, subject to use conditions	No, since January 1, 2025
Section 608 appliance class	High pressure → Type II	High pressure → Type II

GWP values are from EPA's Technology Transitions GWP reference table. Pressures come from the Chemours chart reproduced in our R-32 PT chart.

Is R-32 refrigerant banned in the US?

No. A common search is "why is R-32 banned," and the question rests on history rather than on any current rule.

For years R-32 was not listed for US split systems at all. EPA's SNAP program first listed it in 2015 for self-contained room air conditioners only, such as window and portable units. It was not until SNAP Rule 23, published May 6, 2021, that EPA listed R-32 as acceptable, subject to use conditions, in new residential and light commercial air conditioning and heat pumps. So a technician who learned the trade before 2021 was right that R-32 split systems were not sold here. That is no longer the case.

Today the constraint runs the other way. EPA's Technology Transitions rule caps new residential and light commercial AC and heat pumps at 700 GWP from January 1, 2025 (EPA). R-32 at 675 is legal under that limit, by 25 points. R-410A at 2,088 is not.

Can you put R-32 in an R-410A system?

No. The SNAP listing covers new equipment only, built and listed for R-32 with the flammable-refrigerant use conditions that come with it. Converting an existing R-410A system to R-32 is not a listed use.

The reason goes beyond paperwork. An R-410A system was never designed or tested for a flammable refrigerant. It has no refrigerant detector, no mitigation controls and no charge limit sized to the room. The pressures are close enough to tempt people, but R-32 runs a hotter compressor discharge, and the system's safety design assumes an A1 refrigerant. Go by the nameplate.

Who can buy R-32 refrigerant?

Only certified buyers. Under 40 CFR 82.154(c), the sales restriction has covered non-exempt substitute refrigerants, HFCs included, since January 1, 2018. R-32 is a non-exempt substitute, so it may be sold only to certified technicians, businesses that employ them, and the other buyers the rule lists.

There is one consumer exception, and it is often misread. It covers a non-exempt substitute intended for motor vehicle air conditioning, in a container of two pounds or less with a self-sealing valve. A small can of R-32 sold to top up a mini split is not an MVAC product, so that exception does not describe it. A can being small does not make the sale legal.

If you are working toward the card that lets you buy it, residential split systems are Type II equipment, and our Type II practice test covers the recovery, leak repair and evacuation questions this refrigerant falls under.

Is R-32 flammable?

Yes, mildly. ASHRAE Standard 34 classes it A2L: lower toxicity, lower flammability, and a low burning velocity. It is hard to ignite and burns slowly, but it does burn, which is why equipment built for it carries leak detection and mitigation requirements that R-410A equipment never needed.

Section 608 does not create a separate A2L credential. Your existing Type II or Universal certification covers R-32. The practical change is your equipment, and what EPA actually requires for A2Ls separates the federal rule from manufacturer and code training requirements.

What Section 608 requires, and what is best practice

Item	Status	Source
No knowing venting during service	Regulation	40 CFR 82.154(a)
Sale only to certified buyers	Regulation	40 CFR 82.154(c)
Recovery machine certified for flammable refrigerants (Appendix B4)	Regulation	40 CFR 82.158
Recovery machine manufactured after November 15, 1993 must meet the evacuation table	Regulation, and the date refers to the recovery equipment, not the appliance	40 CFR 82.156
Spark-proof tools, a flammable-rated leak detector, ventilation	Best practice and manufacturer instruction	Equipment literature, local code
Evacuating to 500 microns before charging	Best practice for dehydration, not a Section 608 requirement	Manufacturer instruction

That last row is where most guides get it wrong. The 608 evacuation levels govern how far you pull a system down during recovery. The micron target before charging a new installation comes from the equipment manufacturer. Our guide to pulling a vacuum walks through the difference.

What this means on the job

Set your manifold to R-32, not R-410A. The pressures are within a few psig at coil temperatures, which is exactly why the wrong setting goes unnoticed. The error shows up as superheat that is slightly off.

You can top it off. R-32 is a single compound with no glide, so a small leak does not shift its composition. After you find and fix the leak, you can add refrigerant as vapor or liquid. That is the opposite of R-454B, and our R-32 vs R-454B comparison explains why.

Check your recovery machine's label. A machine certified only under Appendix B3 is not approved for flammable refrigerants. That is a federal requirement, not a shop preference.

Expect to see more of it. Search interest in R-32 has climbed over the past year, and much of it comes from mini split owners. The customer may already know the refrigerant's name and ask you whether they can buy it themselves. The answer is no.

Frequently asked questions

Can I buy R-32 refrigerant in the USA?

Only if you are Section 608 certified or buying for a business that employs certified technicians. R-32 is a non-exempt substitute covered by the sales restriction in 40 CFR 82.154(c). The small-can exception applies only to refrigerant intended for motor vehicle air conditioning, which R-32 sold for a mini split is not.

Which is better, R-32 or R-410A?

For new equipment the question is settled: R-410A's GWP of 2,088 is above EPA's 700 limit for new residential and light commercial AC, while R-32 at 675 is below it. The trade-off is flammability, since R-32 is A2L and R-410A is A1.

Is R-32 refrigerant still legal?

Yes. EPA listed R-32 as acceptable, subject to use conditions, in new residential and light commercial air conditioning and heat pumps in May 2021, and its GWP of 675 is under the 700 limit that took effect January 1, 2025. Servicing R-32 equipment carries the same Section 608 rules as any other HFC.

Can I replace R-22 or R-410A with R-32?

No. EPA's listing covers new equipment designed for R-32, not conversions of existing systems. An R-22 or R-410A system lacks the leak detection, mitigation and charge limits a flammable refrigerant requires. When the old system fails, the options are to repair it on its original refrigerant or replace it with listed equipment.

Do I need a special certification to work on R-32?

No. Section 608 certification is organized by appliance class, not by refrigerant, so a residential split system on R-32 is Type II work. EPA offers no A2L certification. Manufacturers, employers and local codes may require their own flammable-refrigerant training, which is a separate requirement from the federal card.

Sources

• EPA, Technology Transitions GWP Reference Table
• EPA, Technology Transitions HFC Restrictions by Sector
• Federal Register, SNAP Listing Rule 23 (May 6, 2021)
• 40 CFR 82.154 — Prohibitions
• 40 CFR 82.158 — Standards for recovery and/or recycling equipment
• EPA, Section 608 Technician Certification