Exploding Cryovial Injures Student’s Hand

 

 

What Happened?

A student sustained injuries to both hands when a cryovial exploded in his hands. The student was retrieving cryovials from the liquid nitrogen freezer in preparation for an experiment. As a routine practice, the student thawed the cryovials by rolling them between his hands for a few seconds prior to placing them into a 37°C water bath. During this process one of the cryovials exploded. The student immediately went to Occupational Health and Safety where he was diagnosed with first degree burns to both hands. The treating physician submerged the employee’s hands in warm water and applied Lidocaine and bandages. The student was released to go home the same day. He reported the injury to his PI the same day. At the time of the incident the student was wearing the appropriate PPE.

What Was The Cause?

Liquid nitrogen had seeped into the cryovial and rapidly expanded when the student warmed up the vial in his hands. This caused the cryovial to explode.

What Corrective Actions Were Taken?

• Refresher training on how to correctly thaw cryogenic tubes
• Update lab-specific SOP for handling cryogenic fluids

How Can Incidents Like This Be Prevented?

• Store samples for freezing in polypropylene cryovials, ideally containg silicone gaskets; avoid glass or polystyrene vials since they can crack
• If possible, store all cryovials in the nitrogen vapor phase
• Do not over-tighten the caps prior to freezing as this will distort the gasket
• Only vials that are certified for use in liquid nitrogen should be used
• Wear appropriate protective clothing including cryogenic gloves, lab coat and a face shield during transfer processes

Resources

> WARNING: Cryovial Safety UCSF
> How two simple tips can prevent your cryogenic vials from leaking (or exploding)
> Hazards of liquid nitrogen cryovials
> SOP for Handling Cryogenic Fluids

QUICK ACTION TIPS 

Thawing Cryovials

1. Before thawing, loosen cap inside a biosafety cabinet to allow pressure to release.

2. Retighten prior to placing in 37°C water bath for thawing!

  

Liquid Nitrogen

• Freezing pt -210°C; -346°F

• Boiling pt -196°C; -321°F

• Rapidly expands when warmed up and can cause explosions of sealed containers