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Explosion in truck cabin from air-conditioning system


A recent air-conditioning unit explosion, in which a truck driver sustained serious burns, reinforces the need for a crackdown on hydrocarbon refrigerant retrofits, said the industry authority.

Vehicle Air-conditioning Specialists of Australasia (VASA), Australia’s peak body representing the automotive air-conditioning, electrical and thermal management sector, has warned and campaigned about retrofits – replacing the original non-flammable refrigerant with highly flammable hydrocarbon products – for more than two decades.

In that time there have been numerous serious injuries and deaths that would have been avoided if the air-conditioning and refrigeration systems had been using the correct non-flammable refrigerant, or properly re-engineered with the necessary safeguards, to mitigate the risk of using flammable refrigerant, said VASA.

VASA President Ian Stangroome said it is deeply concerning that this latest incident occurred at an underground mining operation, a working environment requiring maintenance of the very highest of safety standards.

“It is particularly discouraging that this happened in Queensland, which is the only jurisdiction in Australia to impose specific controls over the use of hydrocarbon refrigerants,” he said.

“While VASA applauds the Queensland Government for having numerous measures in place to prevent improper use of highly flammable hydrocarbon refrigerants, it seems that in this case the enforcement aspect has been lacking.”

According to an incident report published by Resources Safety & Health Queensland (RSHQ), “the force of the blast dislodged some of the windows of the truck’s cabin and these were blown clear of the truck”.

The explosion caused serious burns to the driver’s face, hands and chest. Fortunately the worker’s eyes were protected from the blast by safety glasses, said the report.

Stangroome added that those who sold hydrocarbon refrigerants to an ignorant marketplace and promoted them as a safe and compatible direct replacement for the product with which a vehicle or piece of equipment left the factory held a large portion of the responsibility for incidents such as this.

“Governments and industry need to do a better job of making people clear on their legal responsibilities, and what is or is not safe,” he said.

“VASA has been warning about the consequences of hydrocarbon retrofits for years and often it seems we are a lone voice in the wilderness – it can be difficult to gain broader industry support on this topic but we will persevere until common sense prevails and the repetition of these incidents cease.”

It is not yet known what the source of ignition was in this latest incident, but the RSHQ investigation so far has concluded that “the release of hydrocarbon refrigerant from the AC into the cab created an explosive atmosphere”.

The source of ignition may never be identified. A report into a 2014 truck explosion in Perth that was caused by the presence of hydrocarbon refrigerants stated that a mixture of propane and air requires just 0.2 millijoules to ignite, which is less than the spark energy from a person’s fingertips when getting out of a vehicle on a cold day.

RSHQ refers to a similar incident in 2014 “when a drill operator in a coal mine suffered burns to the face, hands and torso in an explosion after hydrocarbon refrigerant leaked from the AC system and ignited”.

Other serious hydrocarbon refrigerant incidents recorded around Australia have resulted in two deaths (the Rochester Hotel explosion in regional Victoria) and three serious injuries (a truck explosion in Perth and a major fire at a hydrocarbon refrigerant warehouse in Melbourne).

In New Zealand, the 2008 Tamahere Coolstore incident killed one firefighter and injured seven others when non-standard propane-based refrigerant ignited and caused an explosion.

“Personally, and on behalf of VASA, I extend sympathy to the victim and their family who will now have to endure recovery from serious burns as well as potentially long-term physical, emotional and financial impacts,” added Stangroome.

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