WHS-PRO-024 Cryogen and Compressed Gas Procedure

Intent

This Procedure outlines the requirements for the storage, use, monitoring and emergency response in relation to cryogens and compressed gases at James Cook University (JCU; the University).

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

Scope

This Procedure applies to all JCU staff, students (including Higher Degree by Research (HDR) candidates), Affiliates, visitors, contractors and other persons undertaking JCU-authorised activities involving cryogens and compressed gases. JCU-authorised activities may include but are not limited to teaching, research, placements, and field trips (both domestic and international).

This Procedure does not apply to the Singapore or Brisbane campuses, or to JCU Controlled Entities. JCU staff, students and affiliates are also required to comply with the policies and procedures of other organisations while conducting JCU-authorised activities involving cryogens and compressed gases (for example, during student placements).

Definitions

Except as otherwise specified in this Procedure, the meaning of the terms used are as per the Work Health and Safety Policy or the Policy Glossary.

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

2 Procedures

2.1 Design Cryogenic and Gas Cylinder Storage and Large Quantity Locations

2.2 Use of Cryogenic Liquids

2.2.1 General

2.2.2 Use in Laboratories

2.2.3 Storage

2.2.4 Lift Transport

2.2.5 Vehicle Transport

2.2.6 Dewars

2.3 Compressed Gas (Gas Cylinders)

2.3.1 General

2.3.2 Storage

2.3.3 Lift Transport

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

• Ensure the obligations of this Procedure are complied with.

1.3 Estate Directorate

• Ensure the obligations of this Procedure are complied with;
• Maintain a register of gas monitoring systems and related calibration records;
• 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 requirements of this Procedure.

1.4 WHS Unit

• Ensure the obligations of this Procedure are complied with;
• Provide advice and assistance with the implementation of this Procedure.

2. Procedures

2.1 Design of Cryogenic and Gas Cylinder Storage and Large Quantity Locations

During the design phase of areas to be used for the storage and use of compressed and cryogenic liquids, a risk assessment must be documented.  Applicable risks may include:

• 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;
• Consequences specific to the room assessed;
• Manual handling;
• Leaks occurring at transfer points;
• Filling operations.

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 risk assessment must be conducted for each room within a building where the cryogen/compressed gas will be present. The risk assessment must include the following calculations (including formulas used) that determine:

• Potential for lowering or elevating oxygen levels (<19.5% or greater than 23%);
• Depending on the compressed gas or cryogen, the potential to:
  • Reach exposure standards where applicable, such as carbon dioxide;
  • Reach for explosive or flammable atmosphere.
• The potential atmosphere change from a leak/release, including the risks with ventilation not in operation, and when in depth analysis is needed include calculations for the ventilation operating in the facility.

Decision making requirements to be applied in relation to controls is provided in Table 1 below.

Table 1: Cryogen and Compressed Gas Controls

All cryogen and gas storage locations that have gas monitoring systems, including servicing history, must be kept on a register by the Estate Directorate to ensure calibration and servicing of alarm systems as per the manufacturer’s recommendation.

2.1.1 Design of Gas monitoring system

If the location is identified as requiring a gas monitoring system the following are the minimum controls required:

• 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

In all cases, 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, including:
  • Signage that states what the alarm is and what action to take, e.g., low oxygen alarm - evacuate room;
  • Signage at entry to the space, black and yellow in format, with contact for the space and out of hours contact number
  • Alarm panel with read out external to space being monitored;
  • Alarm system to notify JCU Security and manager of the space through building management system; and
  • Sensors set at heights appropriate for the gas and as per manufacture instruction, e.g., 30cm from ground for gases that are heavier than air.
• 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 persons into the space;
• The room should be designed to include one access door directly to the external of the building that could be used to ventilate the space if required; and
• Doorways 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 as per the below table.

Table 2: Australian New Zealand Standards

2.2 Use of Cryogenic Liquids

2.2.1 General

• Hazards specific to the cryogen in use must be considered, such as asphyxiation, toxicity or fire.
• Safe work instructions must be in place for the activities conducted, such as decanting/filling, responding to alarms and transport of dewars in lifts. Customisable safe work instruction templates are available from the WHS Unit.
• The cryogen container must be labelled in accordance with AS 1894–1997;
• Handling of cryogens requires:
  • Enclosed leather/rubber footwear;
  • Long pants;
  • Non-woven apron;
  • Face shield; and
  • 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, except where a documented risk assessment is in place and appropriate controls are then implemented.
• Use a dry shipper for transport that is designed to allow liquid nitrogen to return to gas and release without building up pressure.

2.2.2 Use in Laboratories

• Quantities of liquid nitrogen <20L can be used within laboratories with at a minimum the following personal protective equipment (PPE):
  • Enclosed leather/rubber footwear;
  • Long pants;
  • Non-woven apron;
  • Face shield; and
  • 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 must include:
  • Potential for lowering or elevating oxygen levels (<19.5% or greater than 23%).
  • Calculations (including formulas used) factoring in ventilation in operation and ventilation not in operation.

2.2.3 Storage

• Storage of cryogenic liquids must meet the relevant Australian Standard.
• Where there is sufficient cryogen stored to create an unsafe atmosphere the space must be redesigned be compliant with Section 2.1 of this Procedure.
• Access to a portable gas monitor with appropriate sensors (example oxygen sensor) may be required in case of emergency.
• The storage facility must be secure and access provided to trained personnel only.
• Vessels must be protected from vehicle collision.

2.2.4 Lift Transport

• 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, there must be a spotter at each floor to stop others from using the lift whilst being used to transport the cryogenic container.

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.
• Tight fitting lids must not be used unless the dewar pressurised.
• Only trolleys designed for moving dewars are to be used.
• Dewars must be labelled with contents.

2.3 Compressed Gas (Gas Cylinders)

2.3.1 General

• 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, and a risk assessment must be documented (refer Section 2.1).
• Within a workshop environment, gas cylinders may be stored in trolleys ready for use (as per the applicable standard).
• 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, except where a documented risk assessment and appropriate controls are then implemented.

2.3.2 Storage

• Storage of gas cylinders must meet the relevant Australian Standard.
• Where there is sufficient gas cylinder storage to create an unsafe atmosphere the space must be redesigned to be compliant with Section 2.1 of this Procedure.
• Access to a portable gas monitor with appropriate sensors is required in case of emergency.
• The storage facility must be secure and access provided to trained personnel only.
• Gas cylinders are to be protected from vehicle collision.

2.3.3 Lift Transport

• 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, there must be a spotter at each floor to stop others from using the lift whilst being used to transport the cryogenic container.

2.3.4 Vehicle Transport

• Gas cylinders must not be transported within the cabin of a vehicle, except for small tanks that contain a compressed air mixture that is breathable without harm.
• Gas cylinders must be securely restrained and transported in accordance with the relevant State and Federal legislative requirements and the manufactures/suppliers instructions (where relevant).
• 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 2.1.1 of this Procedure for design considerations of fixed gas monitoring systems.
• The Estate Directorate is to be notified of all gas monitoring systems 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

2.5.1 General

• Storage of dry ice should be in a labelled insulated container (e.g., esky). Do not seal the container as pressure may build up.
• Do not store in normal freezers, a minus 80 (ultra-low temperature freezer) must 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 an indication that the inner insulation has failed.
• Pressurised dewars and large vessels are to be maintained in line with the requirements AS/NZS 1894-1997.

2.6.2 Reticulated Gas Manifolds and Supply Lines

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

2.6.3 LPG Manifold and Supply Lines

• A listing of the University’s LPG gas manifolds is kept by the Estate Directorate.
• LPG installations are to be compliance tested on installation by a licensed gas fitter, a record of the test must 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 minimum training is required:

• Training provided by the Supervisor in the relevant Safe Work Procedures for the location is required to allow access to the area, including:
  • Responding to alarms;
  • Decanting and filling dewars;
  • Operation of goods lifts with dewars or gas cylinders;
• Training in emergency response requirements, including use of 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 Records Management system (Content Manager) ensures these records are secure and maintained for the required legislated periods outlined in the retention schedules, governed by the Queensland State Archives:

• General Retention and Disposal Schedule; and
• University Sector Retention and Disposal Schedule

Related policy instruments

Work Health and Safety Policy

WHS-PRO-002 WHS Risk Management Procedure

WHS-PRO-010 Hazardous Chemicals Procedure

WHS-PRO-013 Laboratory Safety Procedure

Records Management Policy

Schedules/Appendices

Nil

Administration

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

Approval Details

Revision History