Safe Use of Liquid Nitrogen in Food Processing Plants

  • By PureAire
  • 4th February, 2021

In December 2020,  two employees working at a Vernon, California food processing plant lost consciousness and died following an apparent liquid nitrogen leak. On January 28, 2021, there were several fatalities, and many other employees became sick, after being exposed to nitrogen gas when a liquid nitrogen line ruptured at a food processing plant in Gainesville, Georgia.According to the Occupational Safety and Health Administration (OSHA), a total of fourteen workers died from asphyxiation linked to nitrogen gas in twelve separate workplace accidents recorded between 2012 and 2020, and 2021 is already off to a sad start.  Tragically, these accidents illustrate the dangers of working with liquid nitrogen.

Importance of Liquid Nitrogen in Food Processing

Liquid nitrogen (LN2) is used in food processing in a number of applications, including grinding, mixing, coating, freezing, and packaging foods. Food processors may use liquid nitrogen in the production of a variety of foods, such as meat, poultry, seafood, fruits, vegetables, baked goods, and prepackaged meals. The very low temperature of LN2 is used to flash-freeze foods to help prevent microbial growth that can lead to food spoilage, and to maintain the foods’ original freshness, flavor, and textures.

Oxygen Monitors Can Reduce the Risk of Liquid Nitrogen Accidents

While the use of liquid nitrogen is important in food processing, it is not without risk. When liquid nitrogen is exposed to the air (which happens when leaks occur), it will evaporate, changing from a liquid to an oxygen-depleting gas. Oxygen deprivation can put employees in real danger if there are leaks from pressurized LN2 freezer lines, exhaust systems, or on-site storage containers. In the event of a liquid nitrogen leak, food processing workers could become disoriented, lose consciousness, or even suffocate from breathing oxygen-deficient air. Since LN2 is both odorless and colorless, workers would, in the absence of appropriate monitoring, have no way of knowing that there has been a liquid nitrogen leak.

However, by utilizing a top-quality oxygen deficiency monitor, food plant personnel can safely track oxygen levels and detect leaks before workers’ health is jeopardized.Best practice calls for oxygen deficiency monitors to be installed anywhere there is a risk of liquid nitrogen gas leaks. The monitor should be placed wherever liquid nitrogen is stored, and in all areas where liquid nitrogen is used. The monitoring equipment should include visual and audible alarms that would be activated in the event of liquid nitrogen leaks and a decrease in oxygen levels.

PureAire Monitors

PureAire Monitoring Systems’ line of oxygen deficiency monitors, including a water-resistant unit for facilities requiring daily wash-downs, offers thorough air monitoring, with no time-consuming maintenance or calibration required. In the event of a liquid nitrogen leak, and a decrease in oxygen to an unsafe level, PureAire’s oxygen deficiency monitor will set off an alarm, complete with horns and flashing lights, alerting personnel to evacuate the area. PureAire oxygen deficiency monitors are ideally suited for use in food processing facilities because the monitors can withstand temperatures as low as -40 Celsius. Each PureAire O2 monitor has an easy to read screen, which displays current oxygen levels, for at-a-glance reading by food processing employees, who derive peace of mind from the monitor’s presence and reliable performance.