Pipe Labeling Requirements and Standards

Pipe marking regulations are not always as straightforward as others like PPE or HazCom standards. While OSHA has not put out specific regulations and standards for labeling pipes, OSHA does reference the ANSI/ASME standards. Following the ASME/ANSI A13.1 standard will keep you in compliance with OSHA recommendations.

Pipe Label Standards

Where to put pipe labels

There are four places on a pipe that should be labeled:

  1. Every 25’ to 50’ intervals along straight runs
  2. At all changes in direction (on both sides of the turn)
  3. At both sides of entry points through floors and walls
  4. Next to all flanges and valves

While ANSI/ASME standards recommend labeling every pipe in the facility, OSHA requires pipe labels in the following circumstances:

  • When pipes contain hazardous substances
  • Contents of pipes could impact emergency procedures
  • The flow direction or destination of contents is unknown
  • Maintenance requires that valve(s) be shut off or flow be redirected.

Formatting a pipe label

There are also formatting requirements where the design of a label must comply with the pipe marking standards set forth ANSI and ASME. The measurement of the pipe diameter will determine thee sizes of a label as well as the text size on the label. For instance, if the pipe has a diameter of two inches, the minimum label length is eight inches and the minimum letter height will be three-quarters of an inch.

ANSI/ASME color combinations for pipe labels

The ANSI/ASME 13.1 standard also covers pipe color codes. This is a combination of label color and text color that signify the contents of the pipe. There are six approved color combinations including black text on a yellow label for flammable fluids and gasses and white text on a red label for fire quenching fluids. There are also four user defined color combinations a facility can use to label any contents not covered by the other color standards.

Other standards

While most workplaces will be covered by the ANSI/ASME pipe labeling standards, a handful of other industries have pipe marking standards specific to their line of work. There are a set of standards for example, developed by the International Institute of Ammonia Refrigeration that requires more specific labels for pipes carrying ammonia.  Pipes carrying medical gases will need to follow the NFPA 99/CGA C-9 standard, sea vessels will need to follow the ISO/DIS 14726 standard and waste water treatment places often have their own set of standards.

Additional Resources