CSB Publishes Final Report on Cuisine Solutions Ammonia Release

Yesterday the Chemical Safety Board announced the release of their final report on their investigation of the July 21^st, 2024, anhydrous ammonia release at Cuisine Solutions in Sterling, VA. According to the announcement: “The incident led to a toxic cloud of ammonia that injured dozens of workers and exposed critical deficiencies in the facility’s safety systems.” Along with providing a timeline for the incident and identifying the proximate causes of the release, the report identified three safety issues and produced six recommendations to prevent such releases in the future, four to Cuisine Solutions and two to International Institute of All-Natural Refrigeration (IIAR). This brings to total count of CSB recommendations to 1,025, and the number of open recommendations to 123.

The three safety issues that contributed to the accident were:

• Two-phase Atmospheric Relief

• Discharging to a Safe Location

• Emergency Preparedness

Anhydrous ammonia gas is lighter than air, and when discharged above ground, tends to safely dissipate. The discharge cloud in this case included entrained liquid droplets that fell to the ground; that resulted in an ammonia cloud at ground level near the point of evacuation from the building. This resulted in a number of employees evacuating through a cloud of toxic ammonia gas, thus the large number of injuries.

The four recommendations made by the Board to Cuisine Solutions are:

2024-03-I-VA-3 – Reduce the likelihood or mitigate the consequences of liquid or two-phase atmospheric discharges from the ammonia refrigeration emergency pressure relief system at the Sterling plant.

2024-03-I-VA-4 – Implement an electronic process data historian and management system to ensure that critical process parameters are collected, tracked, and stored.

2024-03-I-VA-5 – Update the Cuisine Solutions Sterling site’s Emergency Action Plan using guidance such as the IIAR’s Critical Task Guidance for Ammonia Refrigeration System Emergency Planning.

2024-03-I-VA-6 – Add an alarm or alarms specific to ammonia releases, so that workers can properly respond to a release.

The two recommendations made to IIAR are:

2024-03-I-VA-1 – Update ANSI/IIAR 2 to include guidance for preventing or mitigating liquid or two-phase atmospheric discharges from emergency pressure relief systems, such as the guidance in API Standard 521, Pressure-relieving and Depressuring Systems.

2024-03-I-VA-2 – Update ANSI/IIAR 2 to include a requirement to assess whether emergency pressure relief devices discharge to a safe location, such as with a dispersion analysis.