This Standard of ANSI Pipe Labeling is intended to establish a common system to assist in identification of hazardous materials conveyed in piping systems and the materials’ hazards when released in the environment. This scheme concerns identification of contents of piping systems. It is recommended for the identification of piping systems used in industrial, commercial, and institutional installations, and in buildings used for public assembly. ANSI Pipe Markings do not apply to buried pipelines nor to electrical conduits.