Contact one of our team members for more best practices and which equipment (including oxygen depletion alarms and transfer equipment) are essential in your lab.

Specific Risks

Extreme Cold - Direct contact with liquid nitrogen can result in severe cold burns or frostbite. Review the following guidelines to create a safe lab environment:

Proper Clothing: Always wear insulated gloves specifically designed for handling cryogenic substances. Use a full-length apron and safety footwear that covers fully to prevent accidental spills into shoes, which can cause severe tissue damage.

Eye Protection: Regular safety glasses are not sufficient. A full face shield or goggles designed to handle extreme cold should be used to protect against potential splashes or debris from frozen materials. 

Avoid Skin Contact: Direct contact with liquid nitrogen can cause severe frostbite or cold burns rapidly. Ensure that all skin is covered with appropriate protective clothing.

Handling and Transfer Tools: Use tools like cryogenic tongs and appropriate transfer vessels that are designed to handle the low temperatures and physical properties of liquid nitrogen to prevent splashing and spillage. 

Training and Awareness: Regular training should be provided on the risks associated with extreme cold, including how to handle spills, first aid for cold burns, and the proper use of personal protective equipment (PPE). 

Safety Signage: Clearly mark areas where liquid nitrogen is used or stored with signs that highlight the dangers of extreme cold and the necessary precautions. 

Emergency Response: Establish and regularly practice emergency procedures for dealing with exposures to extreme cold, including having first aid supplies ready and accessible. Emergency showers and eyewash stations should provide lukewarm water (not hot) to treat any exposure safely.

Asphyxiation Risk - Cryogenic liquids like liquid nitrogen can rapidly form a gas that is colder and heavier than air, leading to potential asphyxiation hazards as it displaces oxygen. 

Accumulation: This cold, heavy gas tends to accumulate at lower levels, not dispersing well, which can increase the risk in poorly ventilated areas. Use an oxygen monitor to test and ensure effective ventilation in the lab.

Silent Danger: Nitrogen is odorless, colorless, tasteless, and non-irritating, lacking typical warning properties. Exposure might not cause noticeable symptoms like light-headedness; individuals might simply lose consciousness without prior warning. 

Critical Oxygen Levels: It's important to monitor oxygen levels as nitrogen enrichment in the air can quickly lead to oxygen-deficient environments. This can be fatal if not managed promptly. Oxygen levels below 19.5% are considered a safety hazard by OSHA and requires mitigation to eliminate the risk.

Pressure-Related Hazards - Implementing these precautions can greatly reduce the risk of injury when working with liquid nitrogen, ensuring that operations involving this cryogenic liquid are conducted safely. 

Over-Pressurization: When liquid nitrogen vaporizes, it expands rapidly, which can cause BLEVE (boiling liquid expanding vapor explosion) if not properly vented.

Safety Measures: Use containers with proper pressure-relief mechanisms to prevent explosions.

Pressure-Relief Devices: Regular checks and maintenance of pressure-relief devices are critical to ensure they function correctly under all conditions, including accidental or unusual circumstances such as external fires or equipment failures.

Safety Precautions for Using Liquid Nitrogen

When using liquid nitrogen (LN2), you should take precautions to avoid burns and asphyxiation. Here are some safety tips:

Ventilation - to prevent the displacement of oxygen and accumulation of nitrogen gas in enclosed spaces

Action: Install ventilation systems designed to maintain adequate airflow and oxygen levels. Regular checks and maintenance of ventilation systems are crucial to ensure their effectiveness.

Monitoring: Use oxygen sensors to continuously monitor air quality, alerting personnel to dangerous levels of oxygen depletion.

Personal Protective Equipment (PPE) - to protect against the hazards of extreme cold and potential splashes from handling liquid nitrogen

Equipment Includes: Cryogenic gloves, face shields, safety goggles, and long aprons.

Training: Regular training on the correct usage of PPE and the risks involved in handling cryogenic substances.

Secure Storage of liquid nitrogen in a manner that mitigates risks of over-pressurization and exposure to extreme cold.

Container Requirements: Use only containers specifically designed for cryogenic materials, such as Dewar flasks with pressure-relief valves.

Location: Store containers in a cool, dry, and well-ventilated area away from heavy foot traffic and direct sunlight.

Equipment Handling to ensure safe transfer and handling of liquid nitrogen

Tools: Utilize equipment such as transfer hoses with phase separators, cryogenic tongs, and vessels designed for low temperatures.

Procedures: Establish clear protocols for the safe handling and transfer of liquid nitrogen, including spill containment strategies.

Emergency Procedures

Skin or Eye contact: In case of contact with liquid nitrogen, immediately use tepid water to gently warm the affected area and seek medical attention if necessary.

Leak and Spill Response: Quickly evacuate the area, ventilate, and mark the location to prevent unauthorized entry. Contact emergency services if the situation escalates.