Update on Liquid Nitrogen Leak Incident in GA Food Facility

Here is an update on the terrible tragedy that occurred in a Georgia poultry plant when a liquid nitrogen leak resulted in six fatalities and 12 hospitalizations. In this case, the liquid nitrogen leaking into the room, replaces the oxygen. It does this because nitrogen gas is heavier and the oxygen is forced up.

It appears that the line in question was experiencing some difficulties and that maintenance was dispatched to the area.  This was unplanned maintenance work and was probably in response to a low level indicator on the control panel. 

We often look at liquid nitrogen as a inert gas, but it can create an oxygen depleted environment, and as a liquid at -320F can instantly freeze skin and and underlying tissue.  This incident is a reminder for facilities to implement safety procedures for maintenance as well as operations.

CSB News Release
https://www.csb.gov/third-csb-update-on-poultry-plant-incident/
Third CSB Update on Poultry Plant Incident

February 7, 2021

This is the third information release from the U.S. Chemical Safety and Hazard Investigation Board (CSB) regarding the Foundation Food Group Incident that occurred January 28, 2021. CSB provided the public with initial facts (January 30, 2021) regarding our investigation into the liquid nitrogen (LN) release at the Foundation Food Group’s Gainesville Plant 4.

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 (The information in the following bullets has been previously released).

• 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 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 nitrogen (from stage 1), to complete the freezing process.

The CSB is releasing the following new facts on the incident:

• 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.
• CSB will continue to provide updates as the investigation progresses.

Meatingplace - INDUSTRY NEWS - PM
https://www.meatingplace.com/Industry/News/Details/97249
Feds point to conveyor belt in deadly nitrogen leak
By Lisa M. Keefe on 2/9/2021

In an update on its investigation posted on its website, the U.S. Chemical Safety and Hazard Investigation Board (CSB) noted that the poultry processor Foundation Food Group 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.”

In fact the line in question, which handles seasoning, cooking, freezing and packaging of poultry products, was shut down on the morning of the incident due to operational issues on the conveyor line, the update said. The company’s maintenance personnel — who handle the routine maintenance of the leased equipment — reported that the computerized measuring system had indicated a low liquid level in the immersion bath used to flash freeze the chicken products.

The liquid nitrogen freezing system had just been installed in the last year, replacing an ammonia-based system. The same type of LN system was newly in use in other parts of the plant that did not have the same issues.