JAN/FEB 2026 RETA Breeze

accidentally overshoot it by a few to several cents? If you haven’t, please buy a lottery ticket and sign my name to it. In the PSM program I manage, we stipulate that our MII is 15% above whatever the normal inventory is. So, if I have a 100,000 lb system, we document that at no point in time will we ever exceed 115,000 lb of ammonia in our system. Why 15%? Because filling all pressure vessels to 80% would prevent the system from being able to run because of the High-Level Cutout Floats being physically mounted at approximately 80% of the vessel capacity (opinions vary on this one). However, we do have calculations showing all pressure vessels at 80% of the vessel capacity, but the document clearly states that the value is purely theoretical in nature. OPERATING PROCEDURES ARE KEY To conclude, it is a good idea to ensure that operating procedures are correct and the operators are trained on those procedures, including what steps to take during a deviation to correct the deviation. From a leadership perspective, the question has to be asked whether the compliance program (PSM, RMP, ARM, SRM-LC) is advanced enough to the point where the operators and managers have the training and sufficient time to calculate every ounce of ammonia lost; or if that time is better served at the outset by continuously strengthening the program to minimize losses through training and mechanical integrity. Victor Dearman, Jr., CIRO, CRST is the Director of PSM at JBS Foods Group, USA. This article is based on his sole opinions and not a reflection of any previous, current or future employer.

tion does not apply to ammonia refrigera tion systems. That said, our industry does things in such a way that might lead an eager environmental health & safety (EHS) manager or engineer into firmly believing that this regulation does apply to us. After all, PSM/RMP is often a hot topic, and everyone wants to be compliant. Now, I am in no way suggesting that our industry should not keep track of their ammonia inventory on a routine basis, but I do not see any useful utility in having operators of ammonia refrigeration system abide to the degree that Class I or Class II refrigerants are required to. Rather, we are required to quantify and document the normal and maximum intended inventory. Let us address those for a moment for clarity. MAXIMUM INTENDED INVENTORY Normal inventory is a combination of what the designer or a system states is needed to properly operate the system under normal operating conditions (not week ends, holidays, power outages, etc.) as well as what you physically charged it with proven by receipts for ammonia delivery. What if the designer information is not available? Then we either have the receipts for ammonia delivery, or we have someone perform the calculations to “quantify” what is actually in the system and compare that to what the inventory should be based on your Process Safety Information (PSI). What is Maximum Intended Inventory (MII)? In short, it is the amount of ammonia that a designer or leadership says that under no circumstances will ever be exceeded . Will it differ from the normal inventory? More likely than not, it will be different. Some believe that MII is how much ammonia the system would hold if someone filled all pressure vessels in the system to 80%. For most of us, we would have ammonia tankers lined-up down the road waiting to get into the facility to deliver that much ammonia, and is therefore theoretical in nature. All MII means is that we document ed, let’s say 100,000 lb of ammonia, as our normal inventory. While we were topping the system off to replace losses, we accidentally put in a little more than we had documented as the normal inventory. Have you ever tried pumping gas into your car or truck (say, $20 worth) and you

tions are done by an outside contractor, it becomes paramount to understand whether the contractor is going to verify the correct level as we did here, or if they are simply documenting the“as running”conditions of the plant on the day they visited. Along the same lines, knowing the refrigeration load also helps us determine how many evaporators can be in defrost at any given time, while keeping in mind needed “surge volume” for the liquid returning from evaporators during said defrost. Nonetheless, if all refrigeration equipment is operating “normally,” then the only place to see real changes will be the primary storage vessels such as the high performance rubber (HPR) or controlled pressure receiver (CPR). And with today’s controls, it would be easy enough to install labels, program in warnings or alarms or, in some systems, use low level shut-down float switches. It is important to note that this should also be evaluated during a process hazard analysis (PHA) as well. Getting back to the original topic, the question becomes, “Are these fugitive emission calculations actually necessary for us to perform?” To answer that question, we have to understand where the idea came from. Welcome to Section 608 of the Clean Air Act enacted by Congress under Title VI of the CAA. Section 608 outlines the require ments for refrigeration systems containing 50 lb or more of Class I or Class II ozone depleting substances. For more information on those substances, see 40CFR 82 Part F of the Code of Federal Regulations. On the website epa.gov/section608/ managing-refrigeration-and-ac-equipment , it starts with “Managing Refrigeration and A/C Equipment” and then states “ Section 608 of the Clean Air Act establishes the National Recycling and Emission Reduction Program. It prohibits individuals from intentionally venting ozone-depleting substances (ODS) refrigerants and their substitutes, such as hydrofluorocarbons (HFC’s) while maintaining, servicing, repairing, or disposing of air conditioning or refrigeration equipment. ” In other words, since anhydrous ammonia is not an HFC and has no ozone depleting potential, as outlined in the provisions of EPA Section 608, the regula

Victor is RETA-RSES's Publications Committee Chair.

Sources: •

University of Madison Wisconsin Industrial Refrigeration Consortium, “Best Practices for Reducing Fugitive Emissions from Industrial Refrigeration Systems, December 2020. “The Form “R”Trap” by Dearman Jr., Victor; RETA BREEZE, Jul/Aug 2019. OSHA’s PSM Standard: osha.gov/laws-regs/ regulations/standardnumber/1910/1910.119

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EPA’s RMP Rule: epa.gov/rmp

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JANUARY/FEBRUARY 2026