CSB publishes Foundation Food Group liquid nitrogen release video

The CSB today released a new safety video on its investigation into the deadly Jan. 28, 2021, liquid nitrogen release at Foundation Food Group’s (FFG) poultry processing plant in Gainesville, Georgia.

The incident killed six people and seriously injured three others.

The release occurred when the bubbler tube that measured and controlled the level of liquid nitrogen in an immersion freezer at the facility was bent, causing an abnormally large amount of liquid nitrogen to be pumped into the freezer, which exceeded the freezer’s capacity.

The excess liquid nitrogen overflowed out of the freezer and then vaporized, forming a deadly vapor cloud inside the poorly-ventilated freezer room. Two people who were in the room at the time of the release died from asphyxiation, and four additional workers also were asphyxiated and died when they entered the freezer room during the incident.

CSB leaders emphasize clear hazard communication

The CSB's new safety video, “Fatal Fog: Liquid Nitrogen Release at Foundation Food Group,” includes an animation of the events leading to the incident, along with commentary from CSB Board Member Sylvia Johnson, Investigator-In-Charge Drew Sahli, Investigators Tyler Nelson and Bill Steiner.

In the video, Johnson said:

“Liquid nitrogen and other chemical asphyxiation incidents are preventable. Management must clearly communicate to workers hazards and emergency response measures. Safety management systems for operations that use liquid nitrogen and other asphyxiants must be improved. Doing so can prevent another tragedy like the one that occurred at Foundation Food Group.”

Newly-installed freezer experienced problems

The incident at FFG occurred on a production line that produces marinated, diced, fully cooked chicken that was then frozen using a liquid nitrogen “immersion spiral” freezer. The freezer was leased to FFG by Messer LLC (Messer), an industrial gas products company.

Messer installed the freezer approximately five weeks prior to the incident, and during that time FFG experienced a series of operational problems with the equipment. Messer returned to FFG on multiple occasions to troubleshoot the issues, but the problems persisted.

Control system misinformed by bent tube

On Jan. 28, 2021, FFG halted chicken production on the line so that maintenance personnel could work on the freezer. The freezer remained on, however.

At some point, the freezer’s bubbler tube was bent above the overflow level of the freezer, which caused the freezer’s nitrogen level control system to believe that the freezer was empty. As a result, the system continued to add liquid nitrogen to the freezer, so much that the freezer overflowed.

Once the liquid nitrogen was released, it quickly vaporized and filled the freezer room with a white fog-like cloud that persisted for more than an hour.

Employees killed while attempting rescue

When an FFG employee observed the two maintenance workers lying motionless on the floor of the freezer, an evacuation was initiated. During the evacuation, at least 14 other FFG employees, including members of management, responded to the incident by either investigating the freezer room or attempting to rescue their coworkers.

The two maintenance workers died from asphyxiation due to the vaporized liquid nitrogen. Four other FFG employees were killed as they attempted to respond to the incident. Three other FFG employees were seriously injured.

CSB highlights 12 recommendations

As in the CSB’s final report on the incident, the safety video covers five key safety issues that contributed to the incident:

1. Single point of failure
2. Atmospheric monitoring and alarm systems
3. Emergency preparedness
4. Process safety management systems
5. Product stewardship

In particular, as the video notes, the CSB found FFG did not have an atmospheric monitoring and alarm system that could have alerted workers to the deadly conditions in the freezer room.

FFG also did not have an effective plan for dealing with a hazardous liquid nitrogen release and did not train its employees about how to safely respond to such a release.

The video also highlighted 12 safety recommendations made by the CSB to several entities, including OSHA, Messer, Gold Creek Foods (the current owner of the FFG facility), the Compressed Gas Association, the National Fire Protection Association (NFPA), and the International Code Council (ICC).