Cryogenic Vial Safe Use Guide

Hello, science enthusiasts! Today, we're venturing into the frosty realm of cryovial safety. Cryovials are indispensable tools in laboratories, enabling the preservation of biological materials at ultra-low temperatures using liquid nitrogen. However, improper handling can lead to hazardous situations, including vial explosions. Let's explore the potential risks and best practices to ensure safe cryovial usage.

Understanding the Hazards

Storing biological samples in cryovials immersed in liquid nitrogen (-196°C) is a common practice. However, if liquid nitrogen seeps into a vial and then rapidly expands upon warming (expanding approximately 690 times from liquid to gas), it can cause the vial to explode. Such incidents pose risks of physical injury, exposure to biohazardous materials, and cross-contamination of samples. 

Case Studies Highlighting the Risks

In April 2012, a cryovial with external threads and a female cap, stored in liquid nitrogen, exploded in a research laboratory, exposing a researcher to potential injury and biohazardous material. A similar incident occurred in July 2020. These events underscore the importance of adhering to proper cryovial handling and storage protocols. 

Best Practices for Cryovial Safety

To mitigate the risks associated with cryovial usage, consider the following guidelines:

1. Select Appropriate Cryovials:

   • Internal Threads with Male Caps: Opt for cryovials featuring internal threads and male caps, as they have a reduced risk of explosion compared to external-threaded vials.
     
   • Certified Vials: Ensure that the vials are certified for cryogenic storage.
     

2. Proper Storage Techniques:

   • Vapor Phase Storage: Store cryovials in the vapor phase of liquid nitrogen to prevent liquid nitrogen from entering the vials.
     
   • Avoid Liquid Phase Immersion: If immersion in liquid nitrogen is necessary, use specialized cryogenic heat-shrink tubing or other safety enclosures that can be heat-sealed to prevent liquid nitrogen ingress.
     

3. Thawing Procedures:

   • Controlled Thawing: When retrieving vials stored in liquid nitrogen, place them in the vapor phase for 24 to 48 hours before thawing to allow any trapped liquid nitrogen to evaporate safely.
     
   • Containment During Thawing: Thaw cryovials in a thick-walled container, fume hood, or biosafety cabinet to contain potential explosions.
     

4. Personal Protective Equipment (PPE):

   • Eye and Face Protection: Always wear chemical splash goggles and a full face shield when handling cryovials and liquid nitrogen.
     
   • Hand Protection: Use waterproof, thermal-insulated gloves (e.g., cryo gloves) that can be quickly removed if liquid nitrogen spills occur.
     
   • Body Protection: Wear long pants, lab coats, and closed-toe shoes to protect against splashes and spills.
     

5. Incident Reporting and Continuous Improvement:

   • Report Incidents Promptly: Any accidents or near misses should be reported immediately to facilitate investigations and prevent future occurrences.
     
   • Review and Update Protocols: Regularly assess and update safety protocols based on incident reports and evolving best practices.

Conclusion

Cryovials are essential for the preservation of biological specimens, but their safe use requires adherence to stringent protocols. By selecting appropriate vials, employing proper storage and thawing techniques, utilizing adequate personal protective equipment, and fostering a culture of safety and incident reporting, laboratories can minimize the risks associated with cryogenic storage. Remember, safety in the lab is not just a policy—it's a practice that protects both researchers and the invaluable samples they study.