Risk Assessment - Handling Liquid Nitrogen
School/ Divisional Unit: School of Medical Sciences
Initial Issue date: 26.6.09
Current Version: 1
Current Version Issue date: 26.6.09
Next review date: 26.6.12
For additional information refer to the OHS Risk Assessment and Control Procedure, the OHS Risk Rating Procedure and the Hierarchy of Risk Controls.
Risk Assessment title: Handling liquid nitrogen
Step 1: Identify the activity
Safe handling of liquid nitrogen for storing biological samples (e.g. cell lines).
- Liquid nitrogen is a cryogenic fluid and must be used safely to prevent injury to the user.
- Liquid nitrogen dewars (containing samples) are stored within a designated room (lower ground floor room 9 (LG9)- accessible by the goods lift or Stairs in the Wallace Wurth building).
- As biological samples are used frequently within the lab, a specific dewar is provided for storage of all samples (LG9).
- Access to this dewar is restricted to members of the lab (ORU/MDU) and the key is located in the office stationary cupboard (rm 502).
- Appropriate personal protective equipment (gloves, face shield and long sleeve lab coat) is provided within the facility and must be worn prior to opening liquid nitrogen dewar.
- Unlock dewar and lift lid upwards (lid should automatically move upwards).
- Samples are stored within cryovials in boxes which are secured within racks in the dewar.
- To store new samples, lift rack from dewar carefully and wait for remaining liquid nitrogen to drain out of boxes. Remove the rack from dewar and use the step ladder provided to aid with this.
- Place rack upon a piece of Styrofoam to avoid damage to the floor and wait a couple of seconds for any remaining liquid nitrogen to evaporate.
- Remove the metal bar securing the boxes and place new cryovials into appropriate box. ALWAYS KEEP FACE SHIELD ON AS CRYOVIALS CAN EXPLODE WHEN REMOVED FROM LIQUID NITROGEN IF ANY AIR LEAKS INTO VIALS.
- Replace metal bar and place rack back into the dewar slowly to avoid any liquid nitrogen splashing.
- Close lid and lock dewar. Remove PPE and close door (door automatically locks).
Step 2: Identify who may be at risk by the activity
Contractors (currently working on the lower ground floor)
Steps 3 to 7: Identify the hazards, risks, and rate the risks
- An activity may be divided into tasks. For each task identify the hazards and associated risks.
- List existing risk controls and determine a risk rating using the UNSW Risk Rating Procedure.
- Additional risk controls may be required to achieve an acceptable level of risk. Re-rate the risk if additional risk controls used.
Step 8 Documentation and supervisor approval
Completed by: Melissa Desouza
Authorised by: (name) (signature)
Step 9: Implement the additional risk controls identified
Indicate briefly what additional risk controls from Step 6 above were implemented, when and by whom.
Risk control: Date: Implemented by:
Step 10: Monitor and review the risk controls
It is important to monitor risk controls and review risk assessments regularly. Review is required when there is a change in the process, relevant legal changes, and where a cause for concern has arisen. Reviews could be scheduled on an annual basis. If the risk assessment has substantially changed a new risk assessment is warranted.
Review date: Reviewed by: Authorised by:
It is a requirement that legal and advisory documentation that supports this risk assessment be listed. Such documentation includes Acts, Regulations, Australian Standards and Codes of Practice, where applicable.
UNSW Concise OHS Risk Rating Table
What you need to do
- Consider what can go wrong that can hurt someone
- Determine what the most likely outcome would be - Consequences
- Determine how likely those consequences are - Likelihood
- Calculate the risk rating
- Required action
CONSEQUENCES: How severely could someone be hurt?
- Severe death or permanent disability to one or more persons
- Major hospital admission required
- Moderate medical treatment required
- Minor first aid required
- Insignificant injuries not requiring first aid
LIKELIHOOD:How likely are those consequences?
- Almost certain expected to occur in most circumstances
- Likely will probably occur in most circumstances
- Possible could occur at some time
- Unlikely is not likely to occur in normal circumstances
- Rare may occur only in exceptional circumstances
|Risk level||Required action|
|Very High|| Act immediately:
The proposed task or process activity must not proceed. Steps must be taken to lower the risk level to as low as reasonably practicable using the hierarchy of risk controls.
|High|| Act today:
The proposed activity can only proceed, provided that:
|Medium|| Act this week:
The proposed task or process can proceed, provided that:
|Low|| Act this month:
Managed by local documented routine procedures which must include application of the hierarchy of controls.