Pipe marking

Pipe marking is the usage of labels, typically color coded, to identify the use, contents and flow direction of pipes inside of industrial and commercial buildings. This information assists personnel when carrying out maintenance and emergency personnel when responding to emergencies.
ANSI/ASME Standards.
In the United States, Occupational Safety and Health Administration regulations recommend following "American Society of Mechanical Engineers Standard A13.1-2015 - Scheme for the Identification of Piping Systems".
The standard states that labels should be placed where easily viewed by a person standing near the pipe at any of the following points:
2015 revisions.
2015 revisions added oxidizing materials to the existing 'Flammables' classification. The other major change allowed and encouraged labels to incorporate the GHS signal word, hazard pictograms, and hazard statements. This addition helped identify additional dangers when dealing with materials that fit into multiple categories, like Hydrogen sulfide, which is both flammable and toxic.<ref name="ANSI/ASME A13.1 2015"></ref>
IIAR BULLETIN #114.
In 2014, the International Institute of Ammonia Refrigeration introduced a specialized label design for use when marking pipes associated with refrigeration systems using ammonia, including information such as the physical state, pressure and purpose in the system.
NFPA 99C 2002.
The National Fire Protection Association have a special labeling system in the standard for Health Care Facilities, such as hospitals and dentistry offices. This standard puts more emphasis on gases found in Medical gas supply systems, which consist of both oxidizing gases and gases that displace oxygen.