JAN/FEB 2026 RETA Breeze

FUGITIVE EMISSIONS in Ammonia Refrigeration

This article describes fugitive emissions and how to manage them for compliance.

Victor Dearman, Jr., CIRO, CRST

C alculating fugitive emissions in ammonia refrigeration systems is an often-misunderstood concept, and one that has been incorrectly used in some instances. This article will serve to explain and simplify what fugitive emissions are and what needs to be done to be compliant. We will also refer to and explore other articles written on the subject, and attempt to describe best practices. This article will not go into great detail about finding locations for ammo nia losses or what to do about them. To begin, we must understand that our first task is to calculate the amount of ammonia in a refrigeration system, to determine whether a facility is subject to OSHA’s Process Safety Management and EPA’s Risk Management Program (PSM/ RMP) standard and regulations, respec tively. If the designer of an ammonia refrigeration system did not calculate the amount of ammonia that would be necessary to properly operate the system, then we must either perform the calcula tions ourselves or have them be performed by a third party, such as an engineer or a refrigeration contractor that has engineers on staff. In most states, if there is a maximum intended inventory of 10,000 lb or more of ammonia, then the facility likely falls into OSHA’s PSM standard as well as

inventory levels ”—as well as 1910.119(f)(1) (ii)(A) – “ Consequences of deviation ”—are two things an operator should always be aware of. Both of these references are found under Operating Procedures. Also, under Process Safety Information 1910.119(d)(2)(i)(d) –“ Safe upper and lower limits of deviations, including those affecting the safety and health of employees. ” In other words, operating procedures must have upper and lower limits of operation, as well as an understanding of the consequences of deviation and steps to correct the deviation. OSHA tells us that we have to be in control of inventory levels, which is primarily assumed to be in vessels, followed by safe upper and lower limits of those vessels. We understand that vessel levels fluctuate over time. This article is not meant to do a deep dive on this, but for reference, let us use a recirculator for this example (the vessel is a high temperature recirculator in a cold storage application operating at approximately 33.5 psig/20 FSST (Figure 1). It might be difficult to make out in the drawing, but left of the level column are call outs directly from the vessel manufac turer. OPL is “operating level,” and in this case, the operating level is 28 ¾ in. from

EPA’s RMP rule (29CFR 1910.119 and 40CFR Part 68, respectively). However, there are states that have lower threshold quantities, such as Nevada, where it is 5,000 lb. Ammonia refrigeration systems are designed to be closed loop (no normal losses) systems, similar to that of freon based systems. However, like anything mechanical, these systems require periodic maintenance, such as equipment rebuilds or replacement, draining of oil from the system because oil inhibits heat transfer and the purging of non-condensable gases, whether through an Auto Purger or performed manually. Additional emissions occur due to valve packing leaks, and unplanned releases through pump outs or other activities. Proper mechanical integrity (ongoing maintenance), well written operating and maintenance procedures, and well-trained operators using said operating or maintenance procedures, as well as ammonia recovery, will help to minimize these losses. We must have documentation to prove how much ammonia we have in our systems and have an understanding that, over time, small amounts of ammonia will be lost from the system through aforemen tioned activities. EPA Risk Management Rule 1910.119(f)(1)(iii)(c) –“ Quality control for raw materials and control of hazardous

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JANUARY/FEBRUARY 2026