Refrigerant cylinder colors

Why every new cylinder is the same gray

For decades, AHRI Guideline N gave each refrigerant its own container paint color. AHRI’s July 2019 announcement explains why that ended. With so many new refrigerants, the number of assigned colors kept growing, and there was concern that similar colors would be confused. More than half of the respondents to an AHRI survey of refrigerant users said container colors had caused confusion.

AHRI Guideline N-2017, section 4.8:

• All refrigerant containers should be painted light green-gray, RAL 7044 (corresponding to PMS 413).
• RAL colors previously assigned could be used until December 31, 2019. By 2020, all refrigerant containers should transition to RAL 7044.
• Existing inventories of previously painted cylinders do not have to be repainted.

The Table 3 note states it flatly: “RAL 7044 applies to all containers of refrigerant as of January 1, 2020.” AHRI’s announcement says the revisions were first published in 2015 and the change commenced in January 2020.

Guideline N is a guideline, not a regulation. It uses “should,” which the document defines as desirable good practice rather than a mandatory provision. Older colored cylinders can still turn up on trucks and shelves.

The red band: flammable refrigerants

Guideline N section 4.7: “A red band on the shoulder or top of the container should designate flammable compounds, or mixtures that could become flammable in the event of a leak.” The guideline defines flammable refrigerants as those rated 2, 2L or 3 under ASHRAE Standard 34. That includes the A2Ls (R-32, R-454B, R-1234yf and the rest) as well as A3 hydrocarbons such as R-290.

The red is PMS 185 (DOT Red). Guideline N lists it “for flammable refrigerant identification when used with primary container color,” and its PMS/RAL table matches it to RAL 3020 (traffic red).

Rheem’s R-454B instructions describe it this way: “Refrigerant cylinders are no longer color-coded. R-454B cylinders are light green gray in color with a red band on the shoulder or top of the cylinder to indicate flammability.”

What the red band means on the job: treat the contents as flammable, use A2L- or A3-rated tools as the refrigerant requires, and keep ignition sources away. See flammability safety classes.

Legacy color chart

These are the PMS colors from Guideline N-2017 Table 1. They now apply only to printed materials such as labels and boxes, plus cylinders painted before 2020. Under section 2.1, the guideline “provides a means by which PMS colors can be assigned to printed materials, such as printed labels on refrigerant containers.”

The table shows why the old system broke down. R-11 and R-404A share orange, and R-23 and R-123 share light blue-gray. Guideline N section 4.4 says color codes “only need to be differentiated within a class” (liquid, low pressure, high pressure, flammable), so the same color could mean different refrigerants in different classes.

R-454B, R-454C and R-1234yf have no color in the Guideline N-2017 table.

Recovery cylinders: gray with a yellow top

Guideline N does not cover recovery containers. Section 2.2 refers them to AHRI Guideline K. Worthington’s recovery cylinder spec sheet says its standard recovery cylinders align with Guideline K, “which states all refrigerant containers will be painted gray with a yellow collar.”

For A2L recovery, Worthington makes a separate line of recovery cylinders with “left hand threads and a red stripe to signify their A2L designation.” Rheem’s A2L service section calls for appropriate recovery cylinders designated and labeled for the recovered refrigerant, and says not to mix refrigerants in recovery units and especially not in cylinders. Fill limits and DOT ratings are on the recovery machine compatibility page.

Left-hand threads

Many cylinders for flammable refrigerants, A2Ls included, use left-hand thread valves, so a standard right-hand hose fitting will not thread onto them. This is industry practice; Guideline N-2017 contains no thread provision. Worthington’s A2L recovery cylinders are one documented example.

Rheem lists the valve outlets for R-454B cylinders as a CGA 164 fitting under 50 lb of refrigerant and a CGA 670 fitting over 50 lb. Check the valve outlet before you connect a hose.

Never identify refrigerant by color

Guideline N says it in three places:

• Section 2.1: “Colors should not be relied upon exclusively to determine the type of Refrigerant in the container.”
• Section 4.1: “The color guideline is not a substitute for reading cylinder labels and markings.”
• AHRI’s 2019 announcement: federal rules (49 CFR for hazmat transport, 29 CFR for occupational safety) require all hazardous material containers, refrigerant cylinders included, to be labeled to identify the contents, and those labels and markings should always be the primary means of identification.

Before you connect a cylinder:

1. Read the label for the refrigerant number. Every new cylinder is the same gray, so the paint tells you nothing beyond the red band.
2. Check for the red band or stripe and treat it as flammable if present.
3. Match the refrigerant to the system nameplate.
4. If a cylinder has no legible label, do not charge from it.