Policy WHS-PRO-024 Cryogen and Compressed Gas Procedure

WHS-PRO-024 Cryogen and Compressed Gas Procedure


Print Friendly and PDFPrint Friendly

Intent

JCU is committed to minimising the risks associated with cryogenic liquids and compressed gas storage and use.  This Procedure outlines the requirements for the storage, use, monitoring and emergency response in relation to cryogens and compressed gases.

In committing to the responsibilities under this Procedure, JCU remains committed to all relevant laws, legislation and University policies, including those providing for a work, study or research environment free from discrimination.

Scope

This Procedure applies to all JCU staff, students (including higher degree by research candidates), affiliates of James Cook University, visitors and contractors and other persons undertaking authorised JCU activities involving cryogenic liquids and compressed gases.

In addition, this Procedure applies to all JCU authorised activities that may include but are not limited to teaching, research, placements, field trips (both domestic and international).

JCU Controlled Entities and related bodies corporate are required to meet the obligations of the relevant legislation, regulations and codes of practice related to cryogenic and compressed gas.  JCU Controlled Entities are not required to comply specifically with this Procedure.

JCU staff, students and affiliates will be required to comply with the Procedures of other organisations while conducting JCU authorised activities (for example during placements).

This Procedure operates in conjunction with WHS-PRO-010 Hazardous Chemicals Procedure and WHS-PRO-013 Laboratory Safety Procedure.

Definitions

Term

Definition

Affiliates

Is a person (other than a Staff member or Student, including Higher Degree by Research Candidates) who is affiliated with JCU by letter of appointment or invitation to work, research or study at the University for a particular activity and typically for a prescribed timeframe and who is bound to comply with the University’s policies during that period (e.g. visiting scholars, adjuncts and volunteers).

Cryogen

A liquid or solid substance that is extremely cold and generates a large volume of gas at atmospheric temperature and pressure.

Dewar Flask

Portable, double walled container, which is normally open necked, free venting and non-pressurized, and is used for storing liquefied gases at low temperature.

Pressurised Dewar

A double walled, vacuum insulated container for the storage of liquefied gases of at least 50L water capacity and at least 50 kPa working pressure.

Table of Contents

1       Duty, Obligations and Responsibilities

1.1         Vice Chancellor

1.2         Deputy Vice Chancellor / Director of Operations / College Manager / Directors / Deans / Head of Discipline / Managers

1.3         Estate Directorate

1.4         WHS Unit

1.5         Laboratory Supervisor

1.6         Staff / Students / Affiliates / Contractors / Visitors

2       Requirements

2.1         Design Cryogenic and Gas Cylinder Storage / Large Quantity Locations

2.2         Cryogenic Liquids

2.2.1           General

2.2.2           Use in Laboratories

2.2.3      Storage

2.2.4           Lift

2.2.5           Vehicle Transport

2.2.6           Dewars

2.3         Compressed Gas

2.3.1           Use of Gas Cylinders

2.3.2           Storage

2.3.3          Lift

2.3.4           Vehicle Transport

2.4         Gas Monitoring System

2.5         Dry Ice

2.5.1           General

2.5.2           Vehicle Transport

2.6         Inspection

2.6.1           Cryogenic Vessel

2.6.2           Reticulated Gas Manifolds and Supply Lines

2.6.3           LPG Manifold and Supply Lines

2.7         Emergency Planning

2.8         Training

2.9         Records

1 Duty, Obligations and Responsibilities

1.1 Vice Chancellor

The Vice Chancellor has responsibility to ensure the University is compliant with this Procedure.

1.2 Deputy Vice Chancellor / Director of Operations / College Manager / Directors / Deans / Head of Discipline / Managers

  • To ensure the obligations of this procedure are complied with;

1.3 Estate Directorate

  • To ensure the obligations of this Procedure are complied with;
  • To maintain a register of gas monitoring systems and related calibration records;
  • To maintain a register of reticulated gas lines and the related commissioning and leak test records;
  • Ensure that the design of storage locations meets the design aspects of this procedure.

1.4 WHS Unit

  • To provide advice and assistance with the implementation of this Procedure.

1.5 Laboratory Supervisor

  • To comply with the obligations of this Procedure.

1.6 Staff / Students / Affiliates / Contractors / Visitors

  • To comply with obligations of this Procedure.

2 Requirements

2.1 Design Cryogenic and Gas Cylinder Storage / Large Quantity Locations

During the design phase of areas to be used for the storage and use (example nuclear magnetic resonance charged with liquid helium and liquid nitrogen) of compressed and cryogenic liquids a Risk Assessment must be documented.  The Risk Assessment must determine the extent of controls required based on the degree of risk being introduced.

This includes:

  • Locations that require fixed gas monitoring systems;
  • Ventilation requirements(including boost ventilation systems);
  • External access doors to cryogen and gas storage areas;
  • Labelling of supply lines;
  • Secure access to storage facilities;
  • Viewing windows on doors and walls;
  • Requirements for intrinsic safety where there is a risk of oxygen enrichment / flammable gas;
  • Floor coverings that cannot be damaged by the substance being used.

The assessment must include the applicable risks:

  • Potential for oxygen depletion and asphyxiation;
  • Potential oxygen enrichment;
  • Toxic effects;
  • Fire and explosion;
  • Pressure build up if system blocks from freezing or other source;
  • Embrittlement of building materials;
  • Specific risk to the room assessed;
  • Manual handling;
  • Leaks occurring at transfer points;
  • Filling operations.

The assessment must be conducted for each room within a building where the gas will be present.  The assessment must include the following calculations that determine:

  • Potential for lowering or elevating oxygen levels (<19.5% or greater than 23%);
  • Depending on the gas or cryogen potential to:
    • Reach exposure standards where applicable, such as carbon dioxide;
    • Reach for explosive or flammable atmosphere.
  • The potential atmosphere from a leak/release including:
    • The risk with ventilation in operation;
    • The worst case of the ventilation not in operation.
  • The formulas used in the calculation must be provided.

Decision making to be applied is included in Table 1 below.

Table 1: Gas Controls

Outcome of Assessment

Requirement

It is not possible for the space to have a hazardous atmosphere even with the ventilation system off.

No specific requirement for monitoring or other engineering controls.

The space could only have a hazardous atmosphere if the ventilation is not operating.

Decision by JCU if gas monitoring system and related controls are required for the specific space.

If the ventilation is not in operation, the space will not be considered operational.

The space could have a hazardous atmosphere with the ventilation on or off.

A gas monitoring system and related controls are required in all instances, or redesign to alter the risk.

Lifts for Dewar Transport.

Key interlock system to allow lift to be sent to predetermined floor and retractable barricade to be included in the design.

All cryogen and gas storage locations that have gas monitoring systems fitted are to be kept on a register at the Estate Directorate to allow calibration and servicing of alarm systems as per the manufacture’s recommendation.

If the location is identified as requiring a gas monitoring system the following are the minimum controls to be in place:

  • Gas monitoring system:
    • Appropriate sensor for the gas -
      • Oxygen sensors are appropriate for inert gases, low oxygen and oxygen enrichment;
      • Toxic sensors such as those for carbon dioxide;
      • Lower explosive limit sensors for flammable and explosive gases;
      • The measurement unit of the display should be consistent with the relevant standard such as in percentage of atmosphere or parts per million.
    • Visible and audible alarm within the space and external to the space -
      • Signage that states what the alarm is and what action to take, e.g., low oxygen alarm - evacuate room.
    • Alarm panel with read out external to space being monitored;
    • Alarm system to notify security and manager of the space through building management system;
    • Sensors set at heights appropriate for the gas and as per manufacture instruction.  Example:
      • 30cm from ground for gases that are heavier than air.
  • Signage at entry to the space, black and yellow in format, with contact for the space and out of hours contact number;
  • A viewing panel that allows the space to be viewed in full without entry;
  • Secure door that can be card swiped or keyed to allow only inducted personnel;
  • Ventilation requirements considering the Australian Standard for the specific storage;
  • The room should be located to allow one access door to the external of the building that could be used to ventilate the space if required;
  • Doors need to have low profile lips to allow trolleys and dewars to be moved in and out with ease.

Any design must be conducted using the applicable Australian New Zealand Standard for the type of facility.

Standard

Title

AS/NZS 1894-1997

The storage and handling of non-flammable cryogenic and refrigerated liquids

AS/NZS 1596:2014

The storage and handling of LP Gas

AS/NZS 4332-2004

The Storage and handling of gases in cylinders

AS/NZS 1596:2014

The storage and handling of LP Gas

2.2 Cryogenic Liquids

The specific hazards of the cryogen in use must be considered such as asphyxiation, toxicity or fire.

2.2.1 General

  • Safe work instruction must be in place for the activities conducted including decanting or filling, responding to alarms and transport of dewars in lifts;
    • There are templates available from the WHS Unit that can be customised for the specific location;
  • Cryogen container must be labelled in accordance with AS 1894 – 1997 the storage and handling of non-flammable cryogenic and refrigerated liquids;
  • Handling of cryogens requires:
    • Enclosed leather/rubber footwear;
    • Long pants;
    • Non-woven apron;
    • Face shield;
    • Gloves for cryogenic decanting;
  • When building ventilation is relied on to keep the atmosphere safe, no work will be conducted within the area if the ventilation system is not operational.  The exception being where a documented Risk Assessment is in place and appropriate controls such as constant gas monitoring are then implemented.

2.2.2 Use in Laboratories

  • Quantities of liquid nitrogen <20L can be used within laboratories with at a minimum the following PPE:
    • Enclosed leather/rubber footwear;
    • Long pants;
    • Non-woven apron;
    • Face shield;
    • Gloves for cryogenic decanting.
  • Quantities >20L require a documented Risk Assessment to determine the controls that are required to be in place.  The Risk Assessment will need to include:
    • Potential for lowering or elevating oxygen levels (<19.5% or greater than 23%);
    • Calculations may need to factor in ventilation in operation and the worst case of the ventilation not in operation;
    • The formulas used in the calculation must be provided;
    • A portable gas monitor may be required as part of the work to confirm a safe atmosphere.

2.2.3 Storage

  • Where there is sufficient cryogen stored to create an unsafe atmosphere the space is to be compliant with Section 2 of this Procedure;
  • Access to a portable gas monitor with appropriate sensors (example oxygen sensor) in case of emergency;
  • The door to the facility is to be secure and access provided to trained personnel only;
  • Vessels are to be protected from vehicle collision.

2.2.4 Lift

  • No person is to travel with a cryogenic container >1L within a lift;
  • The lift must be operated in override mode and the entry barricaded to prevent entry;
    • If the lift cannot be operated in override mode then the procedure must be changed to have a spotter at each floor to stop any inadvertent entry/calling of lift.

2.2.5 Vehicle Transport

  • Dewars must not be transported within the cabin of the vehicle;
  • If transporting <500L of liquid nitrogen the driver does not need a dangerous goods licence and the vehicle does not need dangerous goods placards.

2.2.6 Dewars

  • Only purpose built dewars are to be used for transport or storage of cryogenic liquids;
  • Unless the dewar is a pressurised dewar, tight fitting lids must not be used;
  • Only trolleys designed for moving the containers are to be used;
  • Must be labelled with contents.

2.3 Compressed Gas

When building ventilation is relied on to keep the atmosphere safe, no work will be conducted within the area if the ventilation system is not operational.  The exception being where a documented Risk Assessment and appropriate controls are then implemented.

2.3.1 Use of Gas Cylinders

  • It is preferred that gas cylinders are installed externally to buildings;
  • Where a gas cylinder is to be mounted within a laboratory, the cylinder must be securely mounted by a bracket, chain or other purpose built restraint
    • The assessment mentioned in Section 2 must be documented;
  • Within a workshop shop environment, gas cylinders may be stored in trolleys ready for use as per the applicable standard.

2.3.2 Storage

  • Storages of gas cylinders must meet the relevant Australian Standard;
  • Where there is sufficient gas cylinder storage to create an unsafe atmosphere the space is to be compliant with Section 2 of this Procedure;
  • Access to a portable gas monitor with appropriate sensors in case of emergency;
  • The door to the facility is to be secure and access provided to trained personnel only;
  • Gas cylinders are to be protected from vehicle collision.

2.3.3 Lift

  • No person is to travel with a gas cylinder other than compressed air within a lift;
  • The lift must be operated in override mode and the entry barricaded to prevent entry;
    • If the lift cannot be operated in override mode then the procedure must be changed to have a spotter at each floor to stop any inadvertent entry/calling of lift.

2.3.4 Vehicle Transport

  • Gas cylinders must not be transported within the cabin of a vehicle:
    • With the exception of small tanks that contain a compressed air mixture that is breathable without harm;
      • All cylinders must be securely restrained and transported in accordance with the relevant State and Federal legislative requirements or in some instances the manufactures/suppliers instructions;
  • Gas cylinders are to be secured during transport, in a way that will not allow for inadvertent movements;
  • Consult the Queensland transport guideline for transport of dangerous goods in limited quantities to determine if a dangerous goods licence or placarding is required.  The general limit is:
    • <250kg/L for:
      • Class2.1 Flammable gases (except aerosols);
      • Class 2.3 Toxic gases;
      • <500l for Class Nontoxic nonhazardous gases.

2.4 Gas Monitoring System

  • See Section 2 of this Procedure for design considerations of fixed gas monitoring systems;
  • All gas monitoring systems are to be notified in writing to the Estate Directorate for inclusion on the maintenance and calibration register;
  • Gas monitoring systems must be maintained, inspected and calibrated as per the manufacturer’s requirements;
  • Portable gas monitors are located at the Cairns and Townsville campus.  The locations of the monitors can be obtained from the WHS Unit.

2.5 Dry Ice

Dry ice is carbon dioxide in a solid form.  Dry ice will sublime from a solid state back to gaseous carbon dioxide.

2.5.1 General

  • Storage of dry ice should be in an labelled insulated container (e.g. esky);
  • Do not seal the container as pressure may build up;
  • Use a dry shipper for transport that is designed to allow the CO2 off gassing to escape without building up pressure;
  • Do not store in normal freezers, a minus 80 can be used to stabilise small quantities of dry ice.

2.5.2 Vehicle Transport

  • Dry ice must not be transported within any sealed area of the vehicle;
  • If transporting less than 500kg then dangerous goods licencing or placarding are not required.

2.6 Inspection

2.6.1 Cryogenic Vessel

  • Dewar Flasks are to be inspected regularly by the users, any signs of condensation on the outside of the vessel is a sign that the inner insulation has failed;
  • Pressurised Dewar and large vessels are to be maintained in line with the requirements AS1894-1997 The storage and handling of non-flammable cryogenic and refrigerated liquids.

2.6.2 Reticulated Gas Manifolds and Supply Lines

  • Systems delivering compressed gas or cryogenic gas bleed off are required to be leak tested on installation and a copy of the test provided to the Estate Directorate;
  • The system is to be leak tested every 12 months to ensure its integrity.

2.6.3 LPG Manifold and Supply Lines

  • A listing of the LPG gas manifolds are to be kept by the Estate Directorate;
  • LPG installations are to be compliance tested on installation by a licensed gas fitter, a record of the test will be supplied to the Estate Directorate and a compliance plate installed at the connection point of the system;
  • Annual compliance testing of each LPG system is to be conducted by a licensed gas fitter.

2.7 Emergency Planning

  • Emergency response plans are to be in place for each location that has sufficient cryogenic liquid or gas supplies that could result in:
    • Unsafe atmospheres;
      • Reduced or elevated oxygen content;
      • Flammable atmospheres;
      • Toxic atmospheres;
  • The emergency plan must highlight:
    • Responding to:
      • Fixed gas monitoring system alarm;
      • Spill;
      • Suspected leak;
    • Initial decision to engage Emergency Services:
      • Establish if a person has been overcome by an oxygen deficient or toxic atmosphere;
      • If there is immediate danger of fire or explosion;
    • Contacts for the space;
    • Availability of portable gas monitoring systems and staff trained in the use of these systems;
    • A space is not be to be entered by JCU staff until the atmosphere has been tested and the atmosphere is deemed safe for entry:
      • Oxygen between 19.5% and 21.5%;
      • Lower explosive limit has not been reached;
      • Toxic gases are not present at level exceeding exposure standards.

2.8 Training

The following training is required and set as a minimum:

  • Training in the relevant Safe Work Procedures for the location is required to allow access:
    • Responding to alarms;
    • Decanting and filling dewars;
    • Operation of goods lifts with dewars or gas cylinders;
  • Training in the emergency response requirements including;
    • Use of the portable gas monitors;
  • Cryogen and compressed gas awareness.

2.9 Records

The following records must be retained:

  • Calibration records for gas monitoring systems;
  • Maintenance and inspection records for gas manifolds and supply lines;
  • Commissioning data required under Australian Standards;
  • Training records.

JCU’s preferred EDRMS (Electronic Document and Records Management system) HP TRIM, ensures these records are secure and maintained for the required legislated periods outlined in the retention schedules, governed by the Queensland State Archives:

Related policy instruments

WHS-PRO-010 Hazardous Chemicals Procedure

WHS-PRO-013 Laboratory Safety Procedure

Administration

NOTE:  Printed copies of this procedure are uncontrolled, and currency can only be assured at the time of printing.

Approval Details

Procedure Sponsor

Deputy Vice Chancellor, Services and Resources

Version no

20-1

Date for next Major Review

23/04/2023

Revision History

Version

Approval date

Implementation date

Details

Author

20-1

23/04/2020

15/06/2020

Procedure established.

Biological, Radiation and Chemicals Safety Advisor

Keywords

Cryogen, gas, liquid nitrogen, compressed, reticulated, toxic, flammable, asphyxiate