OHS026
Safe work procedure
1. Completed by: Lance Islip,
2. Suddha Moorkooth
3. minor changes by GT Keenan 2911-2012
The Writing Safe Work Procedures Guideline (OHS027) should be consulted to assist in the completion of this form
Faculty/Division:
SCIENCE
Document number
Protein SWP -4a
School/Unit: Physics Protein laboratory
Liquid Nitrogen bulk storage- Newton Building
Initial Issue date
10/052011
Current version
1.0
Current Version
Issue date
29-11-2012
Next review date
10/05/2016
2.Safe work procedure title and basic description of activity
Title: DISPENSING LIQUID NITROGEN FROM STORAGE TANKS
Description of activity:- DISPENSING LIQUID NITROGEN FROM STORAGE TANKS
3.List Hazards and risk controls as per risk assessment
Associated risk
assessment
number and
location:
Hazards
Weight of Dewar
and liquid
nitrogen
Controls
Exposure to an
asphyxiant and
suffocation
Decant in an open area (ensure roller shutter is open)
Cold burns and
frost bite
PPE so no skin is exposed to splashes or spill, SWP and training, very slowly
add nitrogen to empty containers until they cool sufficiently to prevent
splashing
Fire due to
presence of liquid
oxygen
Removal of ignition sources, SWP and training. Check liquid in container for
a blue tinge – Oxygen present if blueish.
Explosive rupture
of containers
Do not decant into containers with screw on lids or sealable lids. Containers
must be designed for cryogenic use. Check containers for presence of water
prior to first filling.
Do Manual Handling Training, use trolleys for dewars, have help to carry or
push dewars.
4.List resources required including personal protective clothing, chemicals and equipment needed
Leather Gauntlets/Gloves
Laboratory gowns with sleeves pulled over cuffs of Cryogenic Gloves
Liquid proof Shoes
Laboratory Face Shield
Cryogenic apron which goes down to cover the shoes to prevent splash entry.
Long trousers without cuffs which sit over the tops of shoes
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OHS026 safe work procedure
Current Version: 3.0 04/03/2011
5.List step by step instructions or order for undertaking the task
DISPENSING LIQUID NITROGEN FROM STORAGE TANKS
A) Inspect the dewar to be filled.
Dispense only into Dewars that are rated for liquid nitrogen.
o Never use a Dewar that does not have a pressure relief valve or pressure venting lid/stopper.
o Never use Dewars with makeshift or homemade lids/stoppers.
o Use pressure venting lids/stoppers supplied by the Dewar manufacturer
Dispense only into Dewars that are:
o Dry and clean
o Equipped with carrying handles or wheels
o Stable/not in danger of tipping over easily
B) Check condition of Required Personal Protective Equipment and then put it on
o Leather Gauntlets/Gloves
o Lab Coat with sleeves pulled over cuffs of Cryogenic Gloves
o Liquid proof Shoes
o Laboratory Face Shield
o Cryogenic apron
o Long trousers
C) Ensure there are no ignition sources present. Any liquid forming off the piping carrying the liquid nitrogen
will be liquid oxygen.
 If liquid oxygen forms stop dispensing, allow the piping temperature to increase, and then
recommence dispensing.
Persons filling Dewar(s) will be in constant attendance during filling
1. Appropriate personal protective equipment is provided within the facility and must be worn prior to
opening liquid nitrogen tap. Earplugs are optional due to the noise generated from the liquid nitrogen
pipe cooling down.
2. Place hose in the dewar to the bottom of the vessel if possible.
3. DO NOT place face or head over the opening of the dewar during the early stages of filling
4. Turn on tap full, then turn back one full turn. Within 3-5 seconds a cold steam will come out of the hose
and liquid nitrogen soon afterwards.
5. Keep a very close watch on the filling process. One hand should remain on the tap in case an
emergency stop is required.
6. Fill to three quarters full (filling full would cause spillage). Check the depth using the depth guage
provided, and then wait for the liquid N2 to settle before you put the lid on.
7. Turn off tap completely
8. Slowly and carefully remove hose from the dewar taking care not to drip or splash liquid onto yourself
or others and place hose on hook provided.
9. Fit lid to the dewar, leaving a gap for gas to escape. Ensure lid is NOT tight fitting or sealing.
10. Remove PPE.
11. Lock the cage.
6.List emergency shutdown procedures
Turn off the tap if it is safe to do so.
7.List Emergency procedures for how to deal with fires, spills or exposure to hazardous substances
If unable to turn off the tap, leave the area and instruct others to leave the area.
Contact the floor warden or building SECO (x58031) to initiate a floor evacuation (whole building NOT required
to be evacuated).
If you cannot arrange for the floor to be evacuated then press the break glass alarm for a building evacuation.
Contact the OHS unit 9385 1565 or Lance Islip on 0408557965 and ask for an oxygen monitor to be brought
over to gauge when it is safe to return.
If uncontactable then allow 30 minutes before re-entering the building after the spill has stopped.
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OHS026 safe work procedure
Current Version: 3.0 04/03/2011
First aid for cryogenic burns The following procedure should be carried out:
(a) Remove the victim from the possibility of further contact with the liquid or vessel.
(b) Move the victim to a warm place (about 22°C) but do not apply direct heat.
(c) If qualified medical attention is not immediately available, arrange for the victim to
be transported to a hospital without delay.
(d) If immediate hospitalization is not possible, proceed with steps (e) to (i).
(e) Gently, flush the affected areas of the skin with large quantities of unheated tap
water. Do not use hot water or any other form of direct heat.
(f) Loosen any clothing that might restrict the circulation to the affected area but take
care not to remove any clothing frozen to flesh.
(g) Protect the affected areas with dry, sterile, non-adhering dressings. Do not apply too
tightly so as to restrict blood circulation. Keep the affected part at rest.
(h) Treat the patient generally for shock.
(i) Do not give the patient alcohol to drink or tobacco to smoke. Both of these will
restrict blood flow.
8.List Clean up and waste disposal requirements
In case of spill, simply allow it to evaporate harmlessly.
Check that no liquid has become trapped in your clothing, shoes etc.
9.List legislation used in the development of this SWP
NSW OHS Act 2000
NSW OHS Regulation 2001
Australia Dangerous Goods Code
AS 1894:1997 The storage and handling of non-flammable cryogenic and refrigerated liquids
10.List competency required – qualifications, certificates, licensing, training - e.g. course or instruction:
The ability to accurately follow this procedure.
Understanding of the hazards associated with cryogens
Knowledge of nearest running water source for first aid
11.Supervisory approval, And review
Supervisor: Shauna
Simon
Responsibility for SWP review: Shauna
Signature:
Simon
Date of review: 10/05/2014
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OHS026 safe work procedure
Current Version: 3.0 04/03/2011
12.SWP Sign off sheet
SWP name and version:
In signing this section the assessor/ authorisor agrees that the following persons are competent in following this
SWP
Name
Signature
Date
Competent
Name of Assessor/Authoriser
Assessor/Authoriser
signature
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OHS026 safe work procedure
Current Version: 3.0 04/03/2011