Be alert – summer safety warnings for technicians

Cylinders - ARC Field Officers have observed refrigerant cylinders in the back of open-type vehicles, exposed to direct sunlight. Storing cylinders that are exposed to direct sunlight can lead to pressure levels rising and refrigerant being purged through the safety device and into the atmosphere.

Not only is this dangerous, it is bad for the environment and is a breach of the Ozone Protection and Synthetic Greenhouse Gas Management Act 1989, and refrigerant handling codes of practice for both stationary and automotive technicians:

Stationary Code of Practice
14.1.3 Refrigerant cylinders must not be directly heated by flame, radiant heat or uncontrolled direct contact heat, however, warming of the discharging cylinder under controlled conditions to increase the rate of discharge of refrigerant during transfer is permissible.

Automotive code of practice
A.21.1 Refrigerant containers must be stored in a secure, cool place, away from fire risk and sources of direct heating and must be within test date.

A.21.2 Refrigerant containers must be stored at or below 48°C unless otherwise specified by the manufacturer.

Ensure your cylinders are stored in a safe location, and if they are in a vehicle, make sure they are secured and out of direct sunlight.

Are your recovery cylinders to standard?

With an increasing number of high pressure refrigerants on the market, it is vital that your recovery cylinders are to standard. Check the required MPa (megapascal) level at which your cylinder should be. MPa is a unit of measuring pressure, and if it exceeds the required standard for the cylinder you own, it creates a risk of pressure build-up, and could result in automatic purging of regulated gas into the atmosphere. This is a safety and environmental risk. If you don’t know what the MPa of your recovery cylinder should be, check with the wholesaler you bought the cylinder from.

Safework NSW issues safety alert for servicing of refrigeration systems

This alert highlights potential risks associated with the servicing of refrigerant systems and has been re-produced by ARC with permission from Worksafe NSW. It applies to all states and territories, so please contact the relevant Worksafe agency in your area if you have any questions.

Background

A number of serious incidents have resulted in workers being severely burnt when a mixture of refrigerant and compressor oil was expelled and ignited while servicing air conditioning refrigerant systems.

The refrigerant systems contained a non-flammable refrigerant, R22. When mixed with oil, it was ignited by an oxy-acetylene torch used by the workers’ to unsweat the copper fittings, while replacing the refrigerant compressor. It’s believed residual pressure in the system caused the refrigerant and oil to be released from the pipe joint, which contacted an ignition source and started a flash fire.

Observations

Oxy-acetylene torches are commonly used to unsweat copper fittings. This plumbing practice can be extremely hazardous and unsafe unless appropriate control measures are taken.

It should be noted that:

• Refrigerant will remain in solution with compressor oil unless the refrigerant is completely recovered using a reclaim unit. This process may take significant time depending on the size and design of the system.
• Warming or agitating the system will cause the refrigerant to evaporate, resulting in a rise in pressure.
• Attempting to break into a system before all residual refrigerant has been removed can cause a sudden release of refrigerant and oil mist, which will be flammable (it is also unlawful under the Ozone legislation and may incur penalties).
• Heat from a naked flame will likely result in ignition of any expelled refrigerant and oil mist, and can cause trace amounts of refrigerant to decompose and generate highly toxic fumes.

Action required

Review your current procedures and ensure safe working practices include:

• Reclaiming the refrigerant before breaking into the system.
• Ensuring the work area is well ventilated.
• Using pipe cutters or similar to cut the pipe.

The use of an oxy-acetylene torch or similar to unsweat pipe joints should only be carried out as a last resort and under very strict and controlled conditions. If oxy-acetylene torch or similar is used, it is recommended that:

• The relevant requirements of the welding processes code of practice and AS 1674.1 Safety in welding and allied processes are complied with
• The system is purged with dry nitrogen following full recovery of the refrigerant
• Adequate ventilation is provided to remove hazardous gases
• Appropriate personal protective equipment and fire protection equipment is used.

Notify Worksafe of any incidents where persons are exposed to a serious risk associated with an uncontrolled fire.

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