Liquid nitrogen is just what it sounds like, nitrogen in a liquid state. It is widely used as a refrigerant or coolant in the workforce due to its extremely low temperature, -320° F to be exact. It has high demand in many industries such as metal fabrication, healthcare, rubber & plastic, automotive, electronics, food & beverages, pharmaceuticals, and construction; however, it also comes with many hazards. If not handled with caution, there is a catastrophic risk. It lacks warning properties to alert you that it has been released and the extreme cold of this chemical, in a liquid state, can harm the human body by freezing skin and eye fluid, which can lead to cryogenic burns, frostbite, and/or permanent eye damage. Other dangers are asphyxiation, oxygen enrichment and pressure buildup, and explosions.
The recent accident at a plant in Gainesville, Georgia that took the lives of six employees is an unfortunate reminder of how bad accidental exposure to liquid nitrogen can be. While the investigation is still ongoing, it is known that there was a liquid nitrogen leak that caused the oxygen in the atmosphere to become deficient. Proper training on emergency scenarios with hazardous chemicals can make the difference between life and death. If your workplace contains liquid nitrogen, ask yourself this simple question: Are you and your employees prepared for a liquid nitrogen emergency? While every workplace is different and it is up to you to train and prepare based on your atmosphere, we have a list below that are some helpful reminders if you are working around liquid nitrogen.
When handling liquid nitrogen, proper PPE must be worn in order to prevent contact or inhalation.
Use cryogenic gloves, eye protection, face shield, closed-toed shoes, and protective clothing.
Always use containers or systems designed specifically for liquid nitrogen such as cryogenic liquid cylinders or dewars.
Nitrogen in the air reduces the relative amount of oxygen which can create an asphyxiation risk. Do no use or store liquid nitrogen in small rooms, walk-in cold rooms, closets, environmental chambers, or other rooms without proper ventilation.
Since liquid nitrogen has the ability to explode from pressure build-up, NEVER store in a sealed, air-tight container.
Know the difference between a low and high-pressure container. Always check the type before use:
Low- delivery of liquid operating at less than 22 psig.
High- both liquid and gas operating at 230 psig or above.
Liquid nitrogen systems may require ventilation and the use of oxygen monitors with alarms.
Following the above work practices can help minimize your risks of an emergency event caused by liquid nitrogen. Proactive approaches which include safe work practices are always the best way to minimize your chances of an accident happening. Train your employees on how your nitrogen system works, what alarms mean, if remote shut-off is available, and how to react to an emergency in your facility. These actions will help save lives.