JAN/FEB 2026 RETA Breeze

CODES AND STANDARDS: PART 5

IIAR 9: Is It Required RAGAGEP?

By Bill Lape, CARO, CIRO, CRST

I n my last Breeze article, I discussed the selection of an American Petroleum Institute (API) Recommended Practice as Recognized and Generally Accepted Good Engineering Practices (RAGAGEP) for an Ammonia Refrigeration System’s Process Safety Management and Risk Management Plan (PSM-RMP) program. In this issue, I am going to return to discuss ing IIAR standards, but rather than going into the details of a particular standard, I am going to discuss the applicability of the standards, specifically IIAR 9. First, let’s dive into some background. Both OSHA—in 29 CFR 1910.119(d)(3)(F)—and the EPA—in 40 CFR 68.65(d)(1)(vi)—require that a facility’s process safety information (PSI) include the design codes and standards that were used in the construction of the covered process, in this case the ammonia refrigera tion system. The applicable codes and standards for a specific location are found in the adopted building and fire codes for that area. These codes are then enforced by the Authority Having Jurisdiction (AHJ) of that area. The AHJ usually consists of building and fire inspectors. Since 2000, IIAR standards have been adopted by reference in the model codes upon which local codes are based on. The adopted standard, together with the requirements of the building or fire code in question, are enforceable by law. As of 2024, all model codes formally defer to adopted IIAR standards for ammonia refrigeration. This means that the require ments of the Mechanical Refrigeration chapter of those codes do not apply. EXISTING CODES & STANDARDS STILL APPLY

provisions by facilities with existing ammonia refrigeration systems. However, before we jump right to performing this required gap analysis, we have to ask ourselves if IIAR 9 even applies to our facility’s ammonia refrigeration system. IIAR 9 (Addendum A), in Section 1.4, states the following: 1.4.1 Where the minimum system safety requirements in codes and standards that initially governed design and installation of the ammonia refrigeration system are more restrictive than those in this standard, the more restrictive minimum system safety requirements shall continue to apply, unless a provision in this standard specifically states that a reduction from previously applicable codes and standards is allowed as indicated in Section 7.2.10 and Section 7.3.13.2. 1.4.2 Where the minimum system safety requirements of this standard are more restrictive than those in the codes and standards that initially governed design and installation, or where the minimum system safety requirements in the codes and standards that initially governed design and installation cannot be identified, this standard shall establish the minimum system safety requirements. So, IIAR 9 sets the minimum require ments unless those design codes and standards that we identified within our PSI are more restrictive. IIAR 9 goes on to say that if the design codes and standards that governed the initial design are unknown, then the requirements of IIAR 9 apply. This is clarified in the flowchart in Appendix A

However, before we pop the champaign to celebrate, it is important to note two things: first, the edition of the model code that defers to IIAR must be officially adopted by the AHJ; and second, the adopted model code cannot have been amended by the AHJ to remove the deferment. For instance, the state of Florida uses the 2021 Interna tional Mechanical Code (IMC) as the basis for the Florida Mechanical Code. The 2021 IMC defers to IIAR for Mechanical Refrigera tion, BUT the section of the IMC that defers to IIAR was removed by a Florida amend ment. So, in Florida, the provisions of the Mechanical Refrigeration chapter in the Florida Mechanical Code still apply. Continuing our background discussion, it has always been implied that a facility must constantly evaluate changes to design codes and standards, and deter mine if these changes must be implement ed in order to further address the hazards of the process. In other words, they must perform a gap analysis. In May of 2024, changes to the RMP rule took this implica tion and made it formal in 40 CFR 68.67(c) (10), which states that the Process Hazard Analysis (PHA) must address “ any gaps in safety between the codes, standards, or practices to which the process was designed and constructed and the most current version of applicable codes, standards, or practices. ” Now, when people in the industrial refrigeration industry think of performing a gap analysis, they immediately think of IIAR 9, the “Minimum Safety Requirements for Existing Closed-Circuit Ammonia Refrigera tion Systems” standard, which requires that a gap analysis be performed against its

24 RETA.com

JANUARY/FEBRUARY 2026