Purpose

This guide—developed by AIRAH (Australian Institute of Refrigeration, Air Conditioning and Heating)—provides critical safety practices for technicians and engineers working with flammable refrigerants, including hydrocarbons (HCs), HFOs, and R32. It supports compliance with AS/NZS 5149, AS/NZS 60079, and WHS regulations.

1. Understanding Flammable Refrigerants (Section 1.1–1.3)

Flammable refrigerants are classified under A2L, A2, and A3 categories by ASHRAE Standard 34:

  • A2L: Lower flammability, e.g., R32, R1234yf, R1234ze

  • A2: Moderate flammability

  • A3: High flammability, e.g., R290 (Propane), R600a (Isobutane)

Key Property (Page 7–8 Table 2):
A3 refrigerants ignite easily with low minimum ignition energy (~0.25 mJ), while A2L refrigerants require higher energy, making them safer when handled properly.

2. Legal and Safety Obligations (Page 10–12)

Technicians must comply with:

  • Refrigerant Handling Licence (ARCtick) requirements.

  • Work Health and Safety (WHS) Act — Duty to manage risks associated with flammable gases.

  • AS/NZS 5149.1–4 — Design, construction, installation, and maintenance standards for systems using flammable refrigerants.

Employers must ensure safe work procedures, ventilation, leak detection, and emergency plans are in place before servicing.

3. Risk Assessment Before Work (Page 13–15)

Before installation or service:

  • Identify the refrigerant type and charge size.

  • Check ventilation—avoid confined or poorly ventilated spaces.

  • Eliminate ignition sources, such as:

    • Electric heaters, open flames, or tools that produce sparks.

  • Use intrinsically safe equipment certified for explosive atmospheres (Ex-rated tools).

  • Display warning labels “Flammable Refrigerant – No Smoking/No Naked Flame.”

Diagram on page 14 illustrates safe work zoning around refrigerant-containing systems.

4. Installation and Servicing Guidelines (Page 16–21)

  • Use tools and leak detectors rated for A2L/A3 refrigerants.

  • Only competent, trained technicians should handle charging, recovery, or system opening.

  • Maintain bonding and earthing of all metallic parts.

  • Use non-sparking fans in service areas.

  • Never solder or braze when refrigerant is in the system.

  • After installation, test for leaks with nitrogen, not oxygen or air.

Table on page 18 details maximum permissible charge limits for various room sizes and refrigerant classifications.

5. Leak Detection and Ventilation (Page 22–25)

  • Install leak detectors where refrigerant concentration could reach 25% of the Lower Flammability Limit (LFL).

  • For indoor units, use mechanical ventilation capable of at least 30 air changes per hour in case of a leak.

  • Ensure exhaust outlets are directed outdoors, away from ignition sources.

6. Storage and Transport (Page 26–28)

  • Store cylinders in cool, ventilated, and shaded areas, away from heat or sunlight.

  • Separate A3 gases from oxidizing agents.

  • Label storage with Danger – Flammable Gas (Class 2.1) placards.

  • Transport cylinders upright and secured in a vehicle with open airflow.

7. Emergency Procedures (Page 30–33)

In the event of a leak:

  • Evacuate the area immediately.

  • Do not operate electrical switches or phones nearby.

  • Ventilate the area naturally or mechanically.

  • Use a dry chemical extinguisher for small fires (not water).

  • Inform emergency services of the refrigerant type.

Flowchart on page 31 outlines response steps for leaks and fires involving A2L and A3 refrigerants.

8. Training and Competency (Page 35–36)

Technicians must have:

  • A valid refrigerant handling licence.

  • Specialist training in handling flammable refrigerants.

  • Knowledge of risk assessment, leak testing, and emergency control.

AIRAH recommends regular refresher training and adherence to the Flammable Refrigerant Safety Code of Practice 2013.

9. Summary

Flammable refrigerants provide environmental benefits (low GWP) but require strict safety management.
Safe practices include:

  • Correct classification and labeling.

  • Ignition control and proper ventilation.

  • Qualified personnel with suitable equipment.

  • Compliance with AS/NZS standards and WHS obligations.