IIAR, the International Institute of Ammonia Refrigeration, is the world's leading advocate for the safe, reliable, and efficient use of ammonia and other natural refrigerants. The IIAR organization’s mission statement is to “provide advocacy, education, and standards for the benefit of the global community in the safe and sustainable design, installation, and operation of ammonia and other natural refrigerant systems.” Members of the IIAR share their knowledge and experience to produce consensus documents regarding the natural and industrial refrigeration industry.

IIAR Pipe Marking Standards

IIAR provides specific guidelines for labeling ammonia refrigeration piping and system components in Bulletin No. 114. Marking pipes is the best way to quickly communicate important information about the contents of the pipe to everyone in the workplace. This helps ensure the safety of all employees and workplace productivity.

The specific marking standards stem from the ANSI/ASME general pipe marking standards. According to the IIAR, ammonia pipe markers must include the following five sections:

IIAR Ammonia pipe label

  1. Marker Body: The marker body color should be safety orange with the word AMMONIA in black letters.
  2. Physical State Section: If the refrigerant is liquid, LIQ should be printed in black letters on a yellow band around the marker body. If the refrigerant is vapor, VAP should be printed in black letters on a sky-blue band around the marker body. The marker should be applied to the left of the word AMMONIA.
  3. Pressure Level Section: The pressure should be labeled HIGH or LOW. Pressure over 70 psig should be labeled HIGH in black letters on a red band around the marker body. Pressure equal to or less than 70 psig should be labeled LOW in black letters on a green band around the marker body. The marker should be applied to the right of the word AMMONIA.
  4. Abbreviation Section: Abbreviations should be in black lettering on a safety orange field. The abbreviation can be an integral part of the pipe marker on the left of the physical state band, or it can be applied separately.
  5. Directional Arrow: Directional arrows may be printed on the marker body in black and proportionate in size to the marker. The arrows may be applied around the full circumference of the pipe.

Importance of Labeling Ammonia

It's always important for employees to know what’s inside the pipes they are surrounded by, especially if the contents of the pipe may be hazardous. Ammonia-based refrigeration systems present a risk of accidental exposure to high concentrations of ammonia.

According to the United States Department of Labor, ammonia is considered a high health hazard because it is corrosive to the skin, eyes, and lungs. High amounts of exposure can even result in blindness, lung damage, or death. Further, if there is a 15% or higher concentration of ammonia in the air, ammonia can ignite into flame when exposed to an ignition source. Ammonia refrigeration often causes the substance to become even more flammable.

To decrease the risk of any accidental release of ammonia in facilities, proper labeling of pipes is vital.


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