On Saturday, the U.S. Chemical Safety and Hazard Investigation Board (CSB) provided the public with initial facts regarding our investigation into the liquid nitrogen (LN) release at the Foundation Food Group’s Gainesville Plant 4.
We are providing an update of some key facts discovered since Saturday’s briefing.
As a matter of orientation: The event occurred on Line 4, where chicken is processed, to include seasoning, cooking, freezing, and then packaging.
- CSB investigators are focusing on the cryogenic freezing system, based on information from various sources, to include several visits to the Plant 4 by our CSB investigators (This information has been previously released).
The CSB is releasing the following new facts on the incident:
- CSB has now confirmed that both the external and the interior elements of this system were manufactured by Messer. This includes the supply tanks outside, and the interior cryogenic freezing equipment on Line 4.
- Prior to the recent installation of this system, a different type of freezing equipment was used, which was ammonia-based. This equipment is still collocated on Line 4 adjacent to the cryogenic system and has not yet been removed.
- The approach of using LN was introduced to Plant 4 in 2020, as it is also being used on Line 2 in Plant 4.
- As mentioned on Saturday, some tools were located in the vicinity of the Line 4 immersion freezer. We have since learned that unplanned maintenance was being conducted on Line 4.
The system installed is a LN immersion-spiral freezer. This process occurs in two stages. In the first stage, the chicken travels on a conveyer belt and is submerged in LN at a temperature of -320F. In the second stage, the conveyer belt travels through the spiral freezer portion, and the chicken is exposed to recovered gaseous N (from stage 1), to complete the freezing process.
We also know that yesterday, two additional patients have been released from the hospital, and the remaining patient is in fair condition (previously critical).
Since arriving at the scene, the team has been gathering information:
- interviewed key staff with first-hand knowledge of the event,
- examined and collected perishable evidence,
- interfaced with local emergency management, and other agencies and jurisdictions on-site
CSB will continue to provide updates as the investigation progresses.