1 In February 2001 we investigated an incident in a containment level 3 laboratory, reported under RIDDOR, where liquid was ejected from a cryovial into a person's face. The vial was thawing following removal from the liquid phase of a liquid nitrogen storage tank. In this case the individual was not exposed to an infectious agent. The individual had undergone a thorough training programme, which enabled him to take appropriate action, informing relevant persons and fumigating the laboratory in a safe manner.
2 Storage of vials in the liquid phase of liquid nitrogen is not recommended as there is a danger of liquid nitrogen becoming caught in the screw of the lid or inside the vial, expanding on thawing and causing the vial to explode, potentially exposing any persons present to the vial contents. Indeed, manufacturers of some cryovials issue warnings not to use cryogenic vials in the liquid phase of liquid nitrogen in their catalogues, on vial packets and on their websites.
3 Training in emergency fumigation and spillage procedures is
essential for all those who work in containment level 3
laboratories and must be recorded. Laboratory personnel, working at
all levels should be trained to deal with spillages and
emergencies.
