Leica Biosystems LN22 - Manual (Page 9)

9
If an unconscious person remains in such a low-oxygen environment,
death may occur.
In case of emergency immediately call a physician and an ambu-
lance. If breathing stops, apply artificial respiration at once.
• For the reasons just explained, never place LN
2
containers in closed
storage rooms. Due to defects because of improper handling (jolts,
mechanical damage) or simply by normal wear, the evaporation rate
of Dewar vessels may rise to several liters per day. In enclosed
spaces, this will cause a dangerous reduction of the oxygen level in
the air.
• Please remember that the LN22 system evaporates 2 to 3 liters of liq-
uid nitrogen per hour during normal operation. This quantity of liquid
corresponds to 2 to 3 m
3 of GN
2
/h. Therefore, make sure your work
area is kept well ventilated at all times and adhere to the precaution-
ary measures described above.
• Be extremely careful when bringing objects at ambient temperature
into contact with LN
2
. During the first few moments an insulating layer
of gas will form around the object. This makes any significant transfer
of warmth impossible and so comparatively little LN
2
will evaporate.
However, as soon as the object has cooled down sufficiently there
will often occur strong boiling and splashing of LN
2
at a time when it
is no longer expected.
2. Safety