Purpose and scope

This guide supports the safe design, installation, commissioning, service, maintenance, decommissioning and disposal of stationary refrigeration and air-conditioning equipment using flammable refrigerants. All refrigerants can be hazardous if misused; flammable refrigerants require additional controls to prevent releases from reaching an ignition source.

1. Understanding refrigerant classifications

Refrigerant safety classifications combine a toxicity class with a flammability class. The letter identifies toxicity and the number identifies flammability.

2. Legal and safety obligations

A person conducting a business or undertaking must eliminate risks so far as reasonably practicable, or minimise them where elimination is not reasonably practicable. Duties can apply to system owners, operators, designers, manufacturers, importers, suppliers, installers, service providers and workers.

• Use equipment that is designed and certified for the nominated refrigerant.
• Follow current WHS/OHS, electrical safety and dangerous-goods requirements.
• Use the latest applicable Australian Standards and manufacturer instructions.
• Ensure workers are trained, competent and appropriately licensed for the work performed.
• Maintain safe work procedures, emergency plans, records, labels and Safety Data Sheets.

3. Risk assessment before work

Complete and document a site-specific risk assessment before installation, service, repair or decommissioning.

Temporary flammable zone

During charging, recovery and hose connection or disconnection, an anticipated release can create a temporary flammable zone. The AIRAH guide recommends considering a minimum radius of two metres in all directions, with a larger zone where the charge, release scenario or ventilation conditions require it.

4. Installation and servicing controls

• Recover the refrigerant using equipment and cylinders approved for the refrigerant.
• Do not mix refrigerants of different safety groups in a recovery cylinder.
• Purge with oxygen-free dry nitrogen before and during brazing where brazing is permitted.
• Never use oxygen or compressed air for purging, pressure testing or charging.
• Use nitrogen for pressure testing in accordance with the equipment manufacturer's procedure.
• Prefer permanent joints or approved cold-connection methods. Avoid serviceable joints where leaked refrigerant could pool.
• Bond and earth metallic components where required to control static electricity.
• Use accurate scales and do not exceed the specified refrigerant charge.

Tools and equipment

5. Leak detection and ventilation

Detection and ventilation requirements must be determined by the system design, charge, room volume, occupancy, release scenario and applicable standards.

• Treat any detected gas as an indicator of a potentially escalating hazard.
• Position detectors based on refrigerant density, likely leak points and airflow patterns.
• Inspect, calibrate and maintain fixed and portable detectors in accordance with the manufacturer's requirements.
• Direct mechanical exhaust outdoors, away from people, openings, drains and ignition sources.
• Do not rely on odour as the primary means of leak detection.

6. Marking, labelling and records

• Clearly label systems and units containing flammable refrigerant.
• Ensure the nameplate identifies the refrigerant and approximate charge.
• Mark accessible interconnecting pipework at appropriate intervals.
• Keep the current Safety Data Sheet accessible at the workplace.
• Maintain installation, inspection, maintenance, leak-test and refrigerant records.

7. Cylinder storage and transport

Storage

• Use cylinders intended for flammable refrigerants, with protected valves and correct labelling.
• Store cylinders upright, secured, cool, dry and well ventilated.
• Keep cylinders away from heat, direct sunlight, combustible material and ignition sources.
• Segregate flammable gases from oxygen and other incompatible dangerous goods as required.
• Apply the required Class 2.1 placards and danger signage based on stored quantities and jurisdiction.

Transport

• Close the cylinder valve and remove the regulator before loading.
• Keep liquefied-gas cylinders upright and securely restrained.
• Provide effective ventilation to prevent vapour accumulation.
• Do not transport unodourised or recovered flammable refrigerant in an enclosed vehicle.
• Protect cylinders from heat, impact, theft and tampering.
• Meet the current Australian Dangerous Goods Code and state or territory transport requirements.

8. Emergency procedures

Every workplace must have an emergency plan proportionate to the hazards. The plan should address alarm, evacuation, communication, gas detection, shutdown, isolation, first aid, emergency-service notification, training, testing and periodic review.

9. Training and competency

Anyone designing, installing, commissioning, servicing, repairing or maintaining a flammable-refrigerant system must be competent for the task.

• Knowledge of refrigerant properties, flammability, toxicity and asphyxiation hazards.
• Understanding of applicable legislation, standards and manufacturer requirements.
• Practical competency in cylinder handling, charging, leak testing, recovery and disposal.
• Ability to establish temporary flammable zones and control ignition sources.
• Correct use, inspection and maintenance of detectors, tools and PPE.
• Emergency response and evacuation training appropriate to the role.

10. Pre-work safety checklist