ohsrm PART B
School of Molecular Bioscience.
HAZARDOUS PROCEDURE: CRYOGENICS – LIQUID NITROGEN & DRY ICE
Step 3. Assess the risk
Assess the risk for the top priority hazards identified in PART A ie., begin with those rated 1, then 2 etc.
Ref. #
1
2
Description of the hazard or hazardous job
Priority
Identification
Date
5
31/03/2010
5
31/03/2010
Dispensing and working with Liquid Nitrogen or Dry Ice (frozen carbon dioxide).
Direct contact with skin or eyes may result in severe burns (frost-bite) or permanent
tissue damage and loss of sight. Serious injury can result within seconds of contact.
Transporting, Short Term Storage, and Disposal of Liquid Nitrogen & Dry Ice.
Transporting liquid nitrogen and dry ice between two locations exposes the carrier
and other persons encountered en route who are not wearing personal protective
equipment to potentially severe cryogenic related injuries. Transport and storage in
small confined spaces (ie lift, car, room etc) may result in asphyxiation. Transport
and storage in unsuitable containers may result in the vessel exploding.
What makes it hazardous? Consult with the workers to find out which factors are relevant:
Tick relevant boxes and record observations or comments.

The work environment
Movement between areas (eg. between supply area and laboratory) presents a
significant risk of injury to persons encountered en route who are not wearing
personal protection equipment. Enclosed areas such as lifts and small rooms with
the doors closed provide an environment where asphyxiation (suffocation) is
possible due to rapid release of nitrogen excluding oxygen from the area.

The nature of the hazard itself
Certain laboratory techniques require the use of cryogenics to prepare samples for
analysis or storage, and for transportation. Failure to observe safety measures
exposes user, and potentially other colleagues, to significant risk of physical injury,
and in extreme cases, unconsciousness, or death due to asphyxiation.

The individual(s) involved
Requires specific training by authorised staff in the safe use of the hazardous
cryogenic materials.
Record the names of those consulted when assessing the risk
Nick Coleman, Peter Kerr, Joe Dimauro, Jenny Phuyal, Zia Ahmad, Angela Nikolic, Robert Czolij.
Date
31/03/2010
Step 4. Control the risk(s)
Control the risks(s) by addressing the risk factors found in Step 3.
Consider the hierarchy of hazard control and record what controls will be used in the short term and longer term. Record also who
is responsible for implementing the control(s) and the due by date(s).
Describe the risk control(s)
Who is responsible
Due by date
for implementation
ALWAYS wear personal protective equipment (PPE) when handling either
Individual user and
liquid nitrogen or dry ice, including lab coat, insulating (cryogenic) gloves, and
their supervisor.
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safety glasses or preferably full face shield (especially when dispensing liquid
nitrogen from supply cylinder on Level 2 of SMB into dewar)
ALWAYS use approved cryogenic vessels, eg metal dewars for liquid nitrogen
Individual user and
and Styrofoam box WITH lid for dry ice. Using vessels not intended for
their supervisor.
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cryogenic agents risks rupture of the vessel and a SERIOUS spill and injury.
When dispensing from liquid N2 cylinder, ensure supply pipe is a few inches
inside the vessel, not just above it. Slowly turn the supply tap and adjust the
Individual user and
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speed of dispensing to prevent splashing. Turn the tap off immediately when it their supervisor.
starts to splash over. Never leave your dewar unattended.
When collecting dry ice from another container use an appropriate scooping
Individual user and
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instrument or gently tip container to direct the dry ice into your own container.
their supervisor.
Don’t pick up dry ice with bare hands – burns will result.
When using either liquid nitrogen or dry ice in the laboratory ensure that you
Individual user and
work in a well ventilated area to prevent any risk of asphyxiation. NEVER
their supervisor.
TRANSPORT LIQUID N2 IN THE LIFT WITH PEOPLE IN IT! – in this case,
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send the cylinder or dewar to the destination floor alone, and put yellow plastic
chain across the door to let others know not to enter the lift.
Whenever transporting, handling or disposing of liquid nitrogen or dry ice,
ensure you do so in well ventilated areas. Both liquid nitrogen and dry ice are
colourless and odourless, therefore difficult to detect. The evaporation of
either liquid nitrogen or dry ice in small enclosed areas reduces the oxygen
concentration in the air, acting as an asphyxiant
Use suitable cryo-stable equipment for working with cryogenic agents, such
as: ceramic mortar and pestles, metals containers and instruments, and
suitable plastics. Glass dewars and other receptacles are hazardous and can
explode if the glass is fractured (SMB is phasing out glass dewars and
replacing with all-metal ones).
If dispensing liquid nitrogen to another receptacle pour slowly and carefully to
minimise splashing.
Do NOT create a gas-tight seal on any vessel containing either liquid nitrogen
or dry. This can result in explosion and release of extremely cold vapours
and/or liquid, and sharp fragments of the container.
Proper training of staff / students is essential prior to use of cryogenic agents.
Individual user and
their supervisor.
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Individual user and
their supervisor.
Individual user and
their supervisor.
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Supervisor of
researcher / student
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Development and updating of Standard Operating Procedure (SOP)
SMB Safety
Committee.
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Consult SOP before using cryogenics, and observe all risk control
recommendations.
Individual user and
their supervisor.
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Record the names of those consulted when deciding on risk control measures
Peter Kerr, Joe Dimauro, Jenny Phuyal, Zia Ahmad, Angela Nikolic, Robert Czolij, Craig Jackson .
PART B completed by:
Mr Craig JACKSON
Date:
31/03/2010
31/03/2010