CSB issues six recommendations to Cuisine Solutions, IIAR

The U.S. Chemical Safety and Hazard Investigation Board (CSB) yesterday issued six recommendations in its final report on the July 31, 2024, release of hazardous anhydrous ammonia at the Cuisine Solutions, Inc. food processing facility in Sterling, Virginia.

During the incident, a toxic cloud of ammonia injured dozens of workers and exposed critical deficiencies in the facility’s safety systems.

"Toxic ammonia vapors can cause serious injuries and put lives at risk,” said Steve Owens, CSB chairperson. "Companies must ensure that toxic ammonia releases are discharged safely and that they have proper procedures in place to respond appropriately when a release occurs."

Following its own investigation, the Virginia Occupational Safety and Health program (VOSH) issued 10 citations through OSHA totaling $131,535.

Emergency pressure discharge prevention guidance

As a result of its investigation, the CSB issued two recommendations to the International Institute of All-Natural Refrigeration (IIAR) calling for stronger industry guidance on preventing or mitigating two-phase ammonia releases, to help prevent similar incidents in the future.

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. At a minimum, the guidance should:

   1. Identify at-risk scenarios such as horizontal surge vessels and other vessels containing saturated liquid with little vapor space.
   2. Address design considerations and controls to reduce the likelihood of identified scenarios leading to overpressure or equipment failure and ensure vapor-liquid disengagement (the separation of vapor from liquid) during pressure relief for identified scenarios.
   3. Require mitigative safeguards in cases where vapor-liquid disengagement during pressure relief cannot be reliably ensured. This should also include alternative disposal systems where applicable.
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.

Emergency action plan update recommended to Cuisine Solutions

The CSB also issued four safety recommendations to Cuisine Solutions, including significant improvements to the facility’s emergency action plan (EAP).

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. At a minimum:
   1. Identify liquid or two-phase release scenarios, particularly for horizontal surge drums and other vessels containing saturated liquid with little vapor space.
   2. Implement engineering controls to reduce the likelihood of high liquid level, overfill, or boiling overpressure scenarios.
   3. Implement engineering controls to mitigate the consequences of these scenarios where their likelihood cannot be acceptably reduced, such as through emergency pressure control systems, atmospheric knockout drums, or automatic shutdown systems.
   4. Contract a competent third party to audit the pressure relief systems. The audit should ensure that:
      1. All relevant relief scenarios have been identified
      2. Preventive and mitigative engineering controls adequately address the hazards
      3. Engineering controls are maintained in such a way that they function properly when required
4. Implement an electronic process data historian and management system to ensure that critical process parameters are collected, tracked, and stored. The system should be available to refrigeration technicians so that they can monitor the refrigeration system and respond to and investigate process upsets.
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. At a minimum, the updated plan should:
   1. Address indoor and outdoor ammonia releases separately, including the distinct alarms and responses to them.
   2. Clearly specify appropriate evacuation routes and muster points, including alternates.
   3. Provide guidance for using windsocks to remain upwind of a release during evacuation.
   4. Implement shelter-in-place strategies, emergency protective equipment, and emergency shutdowns, as appropriate
   5. Include requirements to conduct annual ammonia release drills that include all onsite personnel (including corporate employees). The annual drills should include separate indoor and outdoor ammonia release scenarios and address the use of windsocks to assist with determining evacuation routes, alternate evacuation routes, muster points, and consideration for the decision to shelter-in-place. Additionally, the drills should exercise each evacuation alarm, emergency protective equipment, and emergency shutdowns, where appropriate.
6. Add an alarm or alarms specific to ammonia releases, so that workers can properly respond to a release. The alarm response should be documented in the updated emergency action plan, and may include multiple distinct alarms and responses, such as one for shelter-in-place and one for evacuation.