The following is a list of key safety measures developed by EPA in coordination with the International Institute of Ammonia Refrigeration (IIAR). They are measures that EPA and IIAR agree are required elements for ammonia refrigeration facilities (regardless of an ammonia refrigeration system’s age or size) for the system to meet the requirements of 40 C.F.R. Part 68 or the General Duty Clause of 42 U.S.C. § 7412(r)(1). The list is not intended to be a complete list of required and important safety measures that address hazards at ammonia refrigeration facilities, but rather a subset of easily verifiable items that could help facilities prevent ammonia releases and prepare for any releases that do occur.
Identifying Hazards
Hazard Addressed:
Releases or safety deficiencies that stem from a failure to identify hazards in the design/operation of the system
Safety Measure:
The facility has completed a process hazard analysis or review.
Operating Activities
Hazard Addressed:
High risk of release from operating or maintenance activity
Safety Measures:
The system has self-closing/quick closing valves on oil pots.
The facility has written procedures for maintenance and operation activities.
Only authorized persons have access to the machinery room and the ability to alter safety settings on equipment.
Maintenance/Mechanical Integrity
Hazard Addressed:
Leaks/releases from maintenance neglect
Safety Measures:
A preventative maintenance program is in place to, among other things, detect and control corrosion, deteriorated vapor barriers, ice buildup, and pipe hammering, and to inspect the integrity of equipment/pipe supports.
All piping system openings except the relief header are plugged or capped, or the valve is locked.
Equipment, piping, and emergency shutdown valves are labeled for easy identification, and pressure vessels have legible, accessible nameplates.
All atmospheric pressure relief valves have been replaced in the last five years with visible confirmation of accessible pressure relief valves.
[Note: Replacement every five years is the general rule but there are two other options in IIAR Bulletin 110, 6.6.3.]
Machinery Room and System Design
Hazard Addressed:
Inability to isolate and properly vent releases
Safety Measures:
The System(s) has/have emergency shut-off and ventilation switches outside each machinery room.
The machinery room(s) has/have functional, tested, ventilation. Air inlets are positioned to avoid recirculation of exhaust air and ensure sufficient inlet air to replace exhausted air.
Documentation exists to show that pressure relief valves that have a common discharge header have adequately sized piping to prevent excessive back pressure on relief valves, or if built prior to 2000, have adequate diameter based on the sum of the relief valve cross-sectional areas.
Emergency Actions
Hazard Addressed:
Inability to regain control and reduce release impact
Safety Measures:
Critical shutoff valves are accessible, and a schematic is in place to show responders where to access them.
EPCRA Tier II reporting is up to date.
Additional Compliance Items
Identifying Hazards
For systems that employ hot gas defrost, the process hazard analysis/review includes an analysis of, and identifies, the engineering and administrative controls for the hazards associated with the potential of vapor propelled liquid slugs and condensation-induced hydraulic shock events.
Operating Activities and Maintenance/Mechanical Integrity
Written procedures are in place for the proper use and care of personal protective equipment.
If respirators are used, facilities know the location of their respirators, and they are inspected and maintained per manufacturer or industry standards.
All changes to automation systems (programmable logic controls and/or supervisory control and data acquisition systems) if present, are subject to the management of change procedures.
Machinery Room and System Design
The facility has engineering controls in place to protect equipment and piping against overpressure due to hydrostatic expansion of trapped liquid refrigerant. Administrative controls are acceptable where hydrostatic overpressure can occur only during maintenance operations.
Eyewash station(s) and safety shower(s) is/are present and functional.
Emergency Actions
Emergency response communication has occurred or has been attempted with the Local Emergency Planning Committee and local responders.
The facility has an emergency action plan pursuant to 29 C.F.R. § 1910.38(a) or an emergency response plan pursuant to 29 C.F.R. § 1910.120(q) and 40 C.F.R. § 68.95.