In the recently released Internation Fire Code (IFC) 2021 edition, the newly designated Section 608 – Mechanical Refrigeration, the code references IIAR 2, 6, 7, 8, and 9 when the refrigerant used is anhydrous ammonia (NH3). The 2021 edition still has many of the long-time requirements that will apply to NH3 systems, such as “emergency access” and more. Here are my favorites and the IIAR references: