For years, NFPA 70, the “National Electric Code” has exempted Engine Rooms/Mechanical Rooms for refrigeration processes using Anhydrous Ammonia from having to be Electrically Classified Hazardous Locations (HAZLOC) as long as the room had “adequate ventilation”. The exemption in NFPA 70 has always been sort of vague and referenced the ventilation requirements in ANSI/ASHRAE 15-1994, Safety Code for Mechanical Refrigeration. But that is ALL CHANGING in 2017 as NFPA 70 2017 is now specifying their own Alarm Set Point if a business wants to use the exception. NFPA 70, 2017 will state: