Guest columnist Daniel R. Kuespert, Ph.D., talks about the International Mechanical Code and why it is so important for refrigeration facilities.

Probably the most important law affecting refrigerated facilities is the mechanical code. Most jurisdictions across the United States impose some sort of technical standards on building systems, including refrigeration. While some other standards and codes apply only to certain refrigerants in certain amounts, the mechanical code governs all refrigeration systems.

Mechanical codes generally are imposed on the state and local levels. Starting as a "model" code published by a nonprofit codemaking body, legislatures add local requirements such as permit fees (often imposed by the local code officials) and create legally binding specifications for whatever the code regulates. (Plumbing, fire and electrical are other common codes.)

In the past, there were three separate code bodies publishing model codes in the United States, including:

  • The International Conference of Building Officials (ICBO), publishing the Uniform Mechanical Code, primarily adopted west of the Mississippi River.

  • The Building Officials and Code Administrators International (BOCAI), publishing the National Codes, primarily used in the North and Midwest.

  • The Southern Building Code Congress International (SBCCI), publishing the Standard Codes, used in the South.

A little more than a decade ago, these three organizations formed the Inter-national Code Council to develop a common model code for the United States. Other organizations such as National Fire Protection Association (NFPA), Arlington, Va., and American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), Atlanta, also have attempted to publish model codes. The only current competitor to the International Mechanical Code is the Uniform Mechanical Code, taken over by a previous publishing partner, the International Association of Plumbing and Mechanical Officials, Ontario, Calif.

At present, the International Mechanical Code 2003 Edition is fully developed and available. IMC has been adopted statewide by 26 states and locally in at least 14 others.

The hallmark of the IMC is its reliance on other voluntary standards. The 2003 IMC references about 150 other standards, including ANSI/ASHRAE 15-1994 and ANSI/IIAR-1992. When the IMC is adopted into law in a jurisdiction, the referenced standards also become legally binding requirements. Unfortunately, because of delays inherent in the model code-making process, the referenced version of a standard rarely is the most up-to-date. This leaves facilities with the headache of attempting to satisfy local officials, who inspect to the referenced standard and federal officials, who press facilities to use the most recent edition of a standard as an Occupational Safety and Health Administration (OSHA), Washington, General Duty obligation.

The three code bodies recently merged, leaving the ICC as the surviving nonprofit organization; ICBO, BOCAI, and SBCCI are now "regional offices" of ICC. Visit the International Code Council at