All new users must undergo induction (to arrange, contact
lab manager
Shu Chen, s.chen@mail.cryst.bbk.ac.uk), fill in the induction
form, and read
and sign the laboratory COSHH form before they can do any work
in the EM
laboratories.
Be careful with the stains
used for negative stain microscopy. Uranyl Acetate is weakly
radioactive, phosphotungstic acid and ammonium molybdate are
toxic, and sodium silicotungstate is harmful. Handle the heavy
metal salts with gloves. Respiratory protection and gloves
must be worn when handling heavy metal salt powder, and it is
important to avoid creating dust and to clean up the balance
and bench areas immediately after use.
Infectious samples such as
prions and toxins are used within the laboratory. All such
samples have associated COSHH procedures. If you are not sure
what a sample is, treat it with caution. All samples which
carry a hazard risk should be labelled as such.
All waste solvent should be
placed in the waste solvent bottle in the safety cabinet.
Chemicals for removal should be referred to the Departmental
Safety Officer.
Sharps are collected in marked
sharps bins and are then taken to a collecting point.
The gas supply to the wet lab
has been disconnected. Do not use naked flames in the lab as
they are a severe risk; use a hotplate instead.
The floors in the laboratory
have been sealed to protect them from liquid nitrogen. Chairs
with non-lockable wheels must not be used on this surface as
they are a potential slip hazard.
The weekly laboratory rota
maintains the liquid nitrogen tanks and checks cleanliness and
safety. The tidier the laboratory is, the safer it is.
Liquid nitrogen
Oxygen depletion is the main
danger from the use of liquid nitrogen. Oxygen monitors have
been installed in all rooms and will issue an alarm if the
oxygen levels in the room fall to dangerous levels. All new
users are shown the alarm system during the Induction. If the
meter reads less than 21% the alarm will sound. If that happens, it is
not safe to stay in the room and it must be evacuated.
The incident should be reported immediately to the EM lab
managers and reception on emergency number 555 (from a college
phone). Put up a
notice prohibiting others from entering the room.
Once the room has been
evacuated and the nitrogen has been allowed to disperse, the
oxygen levels can be checked by an authorised person using the
portable oxygen meter (located at the entrance to the lab),
The room can be used again once the reading has risen above
19%. At no point should the settings on the meter be altered
by anyone other than a service engineer or EM lab manager.
Eye protection and gloves must
be worn whenever handling cryogenic liquids.
Ethane
The preparation of liquid
ethane for cryo work must only be done behind the shield in
the fume hood. Use low flow rates of ethane to prevent
splashing.
Gloves and eye protection must
be worn.
Ethane is flammable and
potentially explosive. Do not use in the presence of flames
and use only in a vented area. Once the ethane cylinder is
open do not switch anything on or off in the fume hood,
including the light. Do not create any static.
Electron
microscope
emergency shut down
In the
case of an
emergency, such as a fire or a building evacuation, follow the
instructions
below. However, personal safety remains a priority at all times
and by no means
should you put yourself at risk.
Press the OFF button on the
Emergency Control Panel, which is on the right hand side of
the EM column. The microscope will shut down and minimize any
hazards to itself or anyone nearby.
Switch off the PC by pressing
the on/off button on the main PC box. Do not use the standard
Windows shutdown procedure.
Immediately leave the
microscope room and follow the normal College evacuation
procedures.
If there is a risk of
electrocution, the main power switches (grey boxes with
levers) for each microscope are located near the exit doors of
the microscope rooms.
Sulphur hexafluoride gas
The FEG
microscope
uses sulphur hexafluoride gas (SF6) for insulation of
the high
tension (HT) tanks and the emission chamber. The gauge on the HT
tank should
read 4.5 bar. If the pressure drops below 4 bar, there
may be a leak.
While this gas is non-toxic, it is heavier than air and will
displace oxygen
from the floor level upwards. If there is a significant leak of
this gas the
oxygen monitor in the room will beep. The microscope will
automatically switch off
and the room should be evacuated.
If the microscope has not
shutdown automatically, press the OFF button on the Emergency
Control Panel on the right hand side of the EM column. Leave
the room. Shut the door and put up a notice
prohibiting others from entering.
Contact the Lab managers Shu
Chen (02076316874) or Natalya Lukoyanova (07920146131)
immediately and notify the reception on the emergency number
555 (from a college phone).