Ammonia Refrigeration Machinery Room Classification

I was recently asked to consult regarding the several Fire and Building Code issues related to Occupancy Classification for an ammonia refrigeration machinery room. Local authorities were under the impression that the machinery room should be classified as a High-Hazard Group H location, but upon further research into the building and mechanical codes, here is what I learned:

• High-Hazard Group H should not be applied to a refrigeration machinery room. 2013 CBC §307.1 (2015 IBC §307.1) states that refrigeration systems “shall not be classified as Group H. but shall be classified as the occupancy that they most nearly resemble“. Furthermore, ANSI/IIAR 2-2014 Standard for Safe Design of Closed-Circuit Ammonia Refrigeration Systems §6.8.2 states the following: “Hazardous (Classified) Locations. Machinery rooms shall be designated Ordinary Locations, as described in the Electrical Code, where the machinery room is provided with emergency ventilation in accordance with Section 6.14.7 and ammonia detection in accordance with Section 6.13.”
• Factory Group F is likely the best fit for a refrigeration machinery room since it includes processing operations that are not classified as a Group H hazardous or Group S storage occupancy (2013 CBC §306.1, 2015 IBC §306.1)
• Chapter 50 of the International Fire Code (IFC) and California Mechanical Code (CFC) are not applicable to the ammonia refrigeration machinery room. Exception 6 in 2013 CFC §5001.1 (and 2015 IFC §5001.1) clearly exempts refrigeration systems from all of the requirements of Chapter 50.
  
• IFC/CFC §606 must be adhered to in its entirety. This entire section applies to mechanical refrigeration systems.