Counterfeit and Contaminated Refrigerant
Why this matters
A cylinder is the one part whose rating is entirely about what is inside it, and nothing on the outside can confirm that. A tech who charges a system from a cylinder that is partly something else does not find out at the gauge. They find out when the compressor fails months later, when a reclaimer refuses the recovered charge as mixed, or, in the worst documented cases, when a contaminant reacts with the aluminum in the system. The HFC phasedown made refrigerant expensive and supply-constrained, which is exactly the condition that brings illegal and counterfeit product into the market.
Before you connect anything to a suspect cylinder
Do not connect a cylinder you suspect to a system, a recovery machine or a manifold you will use on a system. If it contains a contaminant, you have just moved it into the equipment or the hoses.
Keep it away from heat and ignition. Never warm a cylinder with a torch or an open flame, and store a suspect cylinder upright, valve closed and capped, away from ignition sources, in a ventilated space. Some counterfeits have contained flammable substances, and several current replacement refrigerants are themselves mildly flammable (safety class A2L), so an unknown fill should be treated as possibly flammable.
Liquid refrigerant causes frostbite. Gloves rated for cold liquid contact and safety glasses go on before any valve is cracked, including the short purge in the field screen below.
Do not vent it to find out. Knowingly venting refrigerant during service is prohibited by Clean Air Act Section 608 and EPA's rules at 40 CFR Part 82, Subpart F, and that applies to a counterfeit as much as a genuine fill.
How the AIM Act created a market for fakes
The American Innovation and Manufacturing Act of 2020 (the AIM Act) directs EPA to phase down U.S. production and import of HFC refrigerants (R-410A, R-134a, R-404A and others) through an allowance system, toward an 85 percent reduction from the baseline by 2036. Anyone importing HFCs needs allowances. A fill imported without them is illegal product, however accurate its label, and EPA and customs have pursued illegal shipments since the program began.
For a shop this produces two distinct problems that look the same at the counter:
- Illegal but genuine. Correct refrigerant, imported outside the allowance system. The fill may be fine; the legality is not, and buying it supports the trade that undercuts legitimate supply.
- Counterfeit or contaminated. The cylinder contains something other than its label, or the labeled refrigerant mixed with something else. This is the one that damages equipment and can hurt people.
EPA's AIM Act rules have also addressed how cylinders are tracked and what containers may be used, and those provisions have been revised more than once since 2021. Check EPA's current HFC allocation and enforcement pages for what is in force on the day you read this, rather than relying on what a supplier or a forum says.
What a contaminant does
A different refrigerant mixed in shifts pressures and capacity, and the system will not perform to its charging chart. A reclaimer may classify recovered gas that is a mix as non-reclaimable, which turns your recovery cylinder into a disposal problem.
Non-condensables (air, nitrogen) raise head pressure and compressor temperature.
Water, acids and residue attack the oil and the motor windings in a hermetic compressor.
Reactive substances. Counterfeit fills of R-134a found in refrigerated shipping containers were reported to contain methyl chloride (R-40). Methyl chloride reacts with aluminum to form compounds that can ignite on contact with air, and service events on contaminated units included explosions. That incident is why a refrigerant whose identity you cannot confirm is never charged into a system with aluminum components, which is most modern systems.
The field screen: pressure against a known temperature
A closed cylinder holding both liquid and vapor sits at the saturation pressure of its contents for the temperature it is at. That gives a quick screen anyone with a gauge and a probe can run.
The conditions it depends on, all of them.
- Liquid must be present. Weigh the cylinder and compare to its tare weight (stamped on the cylinder). A cylinder down to vapor only reads below saturation and looks like a bad fill when it is just empty.
- The whole cylinder is at one known temperature. Let it sit in a stable room for several hours, out of sun and off a cold floor, then tape a temperature probe to the shell. A cylinder that came out of a cold van an hour ago reads low because it is cold.
- The gauge is proven. A gauge that does not read zero open to atmosphere, or does not match a second gauge, invalidates the result.
- You use the right chart value. For a blend with temperature glide, the closed-cylinder pressure corresponds to the bubble point, the pressure at which liquid starts to boil, on the PT chart.
Reading the direction. A reading meaningfully above the chart points toward non-condensables or a higher-pressure substance. A reading meaningfully below, with liquid present and the temperature confirmed, points toward a lower-pressure substance mixed in or substituted. A reading on the chart does not prove purity.
What the screen cannot catch. A contaminant with a vapor pressure close to the labeled refrigerant's passes this test. That was the problem with the methyl chloride fills: at room temperature its pressure is not far from R-134a's. The screen catches gross mislabeling and heavy mixing, which is worth doing on every unfamiliar cylinder. It does not substitute for a lab.
Worked example: a cylinder from a new source
A four-tech HVAC shop, short of R-410A during a heat wave, buys two cylinders from a seller it has not used before at a noticeably lower price than its distributor. The owner runs the screen on one before anyone uses either.
CYLINDER SCREEN labeled R-410A shop bench
Tare (stamped) 11.0 lb
Gross weight 34.2 lb -> liquid present
Soak 5 h in 72 F room, probe on shell
Shell temp 72 F
Gauge check 0 psig open, matches 2nd gauge
Reference cylinder distributor R-410A, same room,
same gauge: 207 psig
Chart, R-410A, 72 F about 207 psig
Suspect reading 176 psig
Difference 31 psi below chart, about 15%
What each line is doing. The gross weight against the tare shows 23.2 lb of contents, so the cylinder is not running on vapor. The five-hour soak and the shell probe establish the temperature. The reference cylinder is the strongest line on the page: the same gauge, the same room, and a known-good fill read on the chart, which rules out the gauge and the room together. The chart value at 72 F sits between R-410A's roughly 201 psig at 70 F and 217 psig at 75 F.
The call. A reading 31 psi below the chart, with liquid present, the temperature confirmed and the instrument proven, means the contents are not R-410A as labeled. A low reading points toward a lower-pressure substance mixed in. The owner does not try to work out what it is.
What happens next.
- Both cylinders are tagged "do not use, suspect contents," valves closed and capped, stored upright away from ignition sources, and logged in quarantine (See related: The Suspect Counterfeit Quarantine SOP).
- The second cylinder is not opened to test; it came from the same seller and sale and is treated the same.
- The owner contacts the seller and asks for the fill documentation, and contacts a certified reclaimer about sampling. A reclaimer or lab can test a sample against AHRI Standard 700, the industry purity specification for refrigerants, which sets limits on other refrigerants, water, acidity, residue and non-condensables.
- If the lab confirms an illegal or counterfeit product, EPA accepts tips on illegal HFC imports and sales through its enforcement pages.
- The shop records the supplier, the cylinder serials and the result. Because neither cylinder was used, there are no installed-charge records to search. Had a tech already charged from one, those jobs are where the shop starts.
Why not just use it on a lower-value job. The cost of a mixed charge is not proportional to the job: a compressor failure on a cheap repair is the same failure as on an expensive one, and the recovered gas from that system is now mixed too.
What would have passed this cylinder. A reading near 207 psig. That would have cleared gross mislabeling, not certified the fill. A shop still unsure of the seller would have bought from its distributor instead, or sent a sample before using it.
Recovered refrigerant has its own purity rule
Under EPA's Section 608 rules (40 CFR Part 82, Subpart F), refrigerant you recover may be put back into the same owner's equipment, but recovered refrigerant sold to a new owner must first be reclaimed by an EPA-certified reclaimer to the AHRI 700 specification. A "recycled" cylinder offered by a stranger as ready to use, with no reclaimer behind it, fails that rule before the screen is even run.
Sourcing that makes this rare
Buy refrigerant from distributors that buy from producers and importers holding allowances, keep the invoice with the cylinder serial number, and record the cylinder serial on any job where you add charge (See related: The Installed-Part Record SOP). A refrigerant price far under your distributor's during a shortage is the cue to ask where it came from (See related: The Price That Is Too Good). Cylinder requalification markings are their own subject (See related: How to Read a Cylinder Requalification Stamp).
References
- American Innovation and Manufacturing Act of 2020 and EPA's HFC allocation rules at 40 CFR Part 84; check EPA's current program pages for provisions in force
- Clean Air Act Section 608 and 40 CFR Part 82, Subpart F (venting prohibition, recovery, reclamation)
- AHRI Standard 700, Specifications for Refrigerants, in the edition the reclaimer tests to
- See related: The Cylinder That Was Not What the Label Said; The Suspect Counterfeit Quarantine SOP; How to Read a Cylinder Requalification Stamp