Industrial Safety Solutions

Order Now and Get FREE GROUND SHIPPING* For Online Orders!

Call 877-762-9280 now, create custom pipe labels for less!

A13.1-2023 Pipe Labeling Resource Center

Pipe labeling introduction   pipe labeling home

Hazardous materials flow through miles of pipes in most industrial, commercial and institutional facilities. Just like hazardous materials in other environments, piping systems need to be properly labeled to make people aware of the hazardous materials they carry. The ANSI / ASME A13.1 program for identification of piping systems addresses this need by offering a common pipe labeling methodology for use in any facility.

Note: You should always used the latest labeling standard, except when you are already using labels of a previous standard.

Changes in A13.1-2007   pipe labeling home

Between the 1996 and 2007 A13.1 standards, several important changes were made, including color table changes. For facilities with existing labeled pipe installations, it is recommended pipe labels for uniform identification. Where updating is not possible, older standards may be continued, for a clear and consistent hazcomm plan. Industrial Safety Solutions supports all versions of the A13.1 standards, and with a full lineup of pipe labeling supplies.

Changes in A13.1-2020   pipe labeling home

The 2020 A13.1 update included new pipe diameter letter height requirements. It also included guidelines for marking pipes that are no longer in service, as well as additional information on GHS labeling. For facilities with existing labeled pipe installations, it is recommended that you update your old pipe labels for uniform identification. Where updating is not possible, older standards may be continued, for a clear and consistent hazcomm plan. Industrial Safety Solutions supports all versions of the A13.1 standards, and with a full lineup of pipe labeling supplies.

Changes in A13.1-2023   pipe labeling home

The latest A13.1 standard is recommended for all new installations. In the 2023 version of the A13.1 standard (A13.1-2023) the color section was updated, and ASME 13.1 was designated as a continuous-maintenance standard. Some updates to flow direction and GHS requirements were updated.

Pipe Labeling Colors   pipe labeling home

ANSI / ASME A13.1 pipe labeling standards define the proper colors schemes for pipe labeling. All versions of the ASME 13.1 pipe labeling standard are still widely used. Multiple color schemes are referenced below - depending on your company policy, compliance update schedules and existing labeling, you may choose to use the standard that best fits your hazcomm pipe labeling plan.

ANSI / ASME A13.1-1996 Standard (for reference)

Classification Sub-Classification Label Color
Materials Inherently Hazardous
  • Flammable or Explosive
  • Chemically Active or Toxic
  • Extreme Temperature or Pressure
  • Radioactive
 BLACK ON YELLOW
Materials of Inherently Low Hazard Liquid or Liquid Admixture WHITE ON GREEN
Gas or Gaseous Admixture WHITE ON BLUE
Fire Quenching Materials Water, Foam, CO2, Halon, etc. WHITE ON RED

ANSI / ASME A13.1-2007 Standard (for reference)

Fluid Service Color Scheme
Fire Quenching Liquids WHITE ON RED
Toxic and Corrosive Liquids BLACK ON ORANGE
Flammable Liquids BLACK ON YELLOW
Combustible Liquids WHITE ON BROWN
Potable, Cooling, Boiler Feed and other water WHITE ON GREEN
Compressed Air WHITE ON BLUE

ANSI / ASME A13.1-2020 Standard (for reference)

Fluid Service Color Scheme
Fire Quenching Liquids WHITE ON RED
Toxic and Corrosive Liquids BLACK ON ORANGE
Flammable Liquids BLACK ON YELLOW
Combustible Liquids WHITE ON BROWN
Potable, Cooling, Boiler Feed and other water WHITE ON GREEN
Compressed Air WHITE ON BLUE

ANSI / ASME A13.1-2023 Standard (current)

Fluid Service Color Scheme
Fire Quenching Liquids WHITE ON RED
Toxic and Corrosive Liquids BLACK ON ORANGE
Flammable, Combustible, and Oxidizing Liquids BLACK ON YELLOW
Steam, Boiler Feed, or other Hot Water BLACK ON GREY
Potable, Cooling, Boiler Feed and other water WHITE ON GREEN
Compressed Air WHITE ON BLUE

Which pipes need to be labeled?   pipe labeling home

For optimal workplace safety, every above-ground pipe should be labeled. Highly visible or frequently accessed pipes may be the most important to label for day-to-day safety, but difficult to locate or infrequently accessed pipes should be labeled as well. Labeling pipes according to ANSI A13 helps guarantee a safe work environment.

What are the pipe labeling requirements?   

Pipe marking labels must effectively communicate the contents of the pipes and give additional detail if special hazards (such as extreme temperatures or pressures) exist. The legend should be short in length and easy to understand. For example, the legend "Steam 100 PSIG" specifies the contents as well as the additional pressure hazard. Arrows should be used in conjunction with the legend to show which direction the material flows (double arrows are appropriate for pipes that flow in both directions).

Label and Letter Sizes for ASME 13.1-2023

The letters on pipe labels should be a minimum of 1/2" high, and should increase in size as the pipe diameter increases. The following table indicates ANSI-recommended letter height for various pipe sizes.

Outer Pipe Diameter (OD) tside Pipe Diameter Minimum Label Length Minimum Text Size
.7" to 1.3" (18 to 33 mm) 8" (200 mm) .5" (13 mm)
1.4" to 2.4" (34 to 61 mm) 8" (200 mm) .7" (19 mm)
2.5" to 6.7" (62 to 170 mm) 12" (300 mm) 1.3" (32 mm)
6.8’ to 10" (171 to 254 mm) 24" (600 mm) 2.5" (64 mm)
Over 10" (Over 254 mm) 32" (800 mm) 3.5" (89 mm)

Are there strict rules for pipe label placement?   

The main thing to remember is that labels should be positioned on the pipes so they can be easily read. Proper label placement is on the lower side of the pipe if the employee has to look up to the pipe, on the upper side of the pipe if the employee has to look down towards the pipe, or directly facing the employee if on the same level as the pipe. Labels should be located near valves, branches, where a change in direction occurs, on entry/re-entry points through walls or floors, and on straight segments with spacing between labels that allows for easy identification.

What pipe labeling products are offered?   

Industrial Safety Solutions offers durable vinyl labeling tape in all the required sizes and colors for ANSI ASME 13.1-2023 pipe marking. Our pipe labeling printer packages ship complete with software to help you quickly and easily create custom pipe marking labels. We also provide free full-color pipe marking guides.