Federal investigators have released a third report from the ongoing probe into a deadly chemical leak at a Gainesville poultry processing plant, saying the probe has unveiled "unresolved operation issues" on a conveyor line where the leak occurred.
The U.S. Chemical Safety and Hazard Investigation Board (CSB) has been part of the ongoing investigation at Foundation Food Group's Gainesville Plant 4 on Memorial Park Drive since the incident occurred the morning of Jan. 28.
Investigators said the incident happened on Line 4, where chicken is processed - that process includes seasoning, cooking, freezing and packaging. The CSB investigation focuses on the cryogenic freezing system used on the line.
Among the newest discoveries in the CSB probe is a finding that the ongoing operational issues on the line resulted in the accidental release of liquid nitrogen into the flash freezing bath. Investigators also discovered Line 4 had been shut down the morning of the nitrogen leak.
Six employees of Foundation Food Group died as a result of the liquid nitrogen leak. Eleven people - workers and firefighters who responded to the scene - were hospitalized from injuries received on scene.
The following information was included in a CSB informational release made public Sunday, Feb. 7:
Information determined in the earlier investigation of the incident:
- CSB has 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 during our first briefing, 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 on line 4 is an 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 nitrogen (from stage 1), to complete the freezing process.
New facts on the incident from Sunday's release:
- The LN units were manufactured and installed by Messer and are leased to the Foundation Food Group.
- The Foundation Food Group performs routine maintenance on the Messer-owned equipment.
- The plant had been experiencing unresolved operational issues on the chicken conveyor that appear to have resulted in the accidental release of liquid nitrogen in the flash freezing bath.
- The CSB has information that Line No. 4 was shut down the morning of the incident. The shutdown was due to operational issues on the conveyor line.
- Foundation Food Group maintenance personnel reported the computerized measuring system indicated a low liquid level in the immersion bath used to flash freeze the chicken products.
