Lab Safety   What are cryogens and why are they hazardous?
Cryogens are liquefied gases that can condense oxygen from the
air to create an oxygen rich atmosphere in the nitrogen
solution; increasing the potential for fire if flammable or
combustible materials are present. Asphyxiation and container
over-pressurization are significant hazards due to the large
expansion ratio from liquid to gas (700 to 1). Many materials
become brittle at extremely low temperatures. Brief contact with
materials at extremely low temperatures can cause burns similar
to thermal burns. Some of the hazards associated with cryogens
are fire, pressure, weakening of materials, and skin or eye
burns upon contact with the liquid.   What is a dewar?  A dewar
is an insulated container used to store and transport liquefied
gases. It is insulated by a vacuum between its two walls and is
equipped with pressure relief device    How should I handle
cryogenic materials?    • All equipment being used should be
clean and capable of withstanding v