A truck driver at an underground mine in Queensland has sustained serious burns to their face, hands and chest from an explosion caused by the vehicle’s air-conditioning system, which was found to have been charged with hydrocarbon refrigerant.
The incident happened on January 11 this year, while the worker was driving in the underground mine. Resources Safety & Health Queensland (RSHQ) reports that safety glasses protected the truck driver’s eyes from injury.
“The force of the blast dislodged some of the windows of the truck’s cabin and these were blown clear of the truck,” says the RSHQ report, which included images of a deformed metal cabin filter panel and fragments of window that were ejected during the explosion.
An investigation into the incident is underway but initial findings are that the air-conditioning system was “charged with a refrigerant containing propane and isobutane (hydrocarbon) instead of compliance with the original equipment manufacturer (OEM) requirement which stipulates the use of R134a refrigerant”.
The system was also “not certified for the use of the hydrocarbon refrigerant”.
Furthermore, the people who serviced and charged the truck’s air-conditioning system did not hold the requisite Queensland Gas Work Licenses for working with hydrocarbon refrigerant.
It is not yet known what the source of ignition was, but the investigation so far has concluded that “the release of hydrocarbon refrigerant from the AC into the cab created an explosive atmosphere”.
RSHQ has indicated that it may publish more information about this incident as the investigation progresses.
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).
Recommendations in the RSHQ safety alert include that the senior site executive must:
- Inspect all refrigeration plant and equipment including AC units on mobile plant to verify compliance with OEM guidance with regards to refrigerant(s)
- Any refrigeration plant and equipment charged with refrigerant(s) not specified by the OEM must be immediately quarantined from use
- If an alternate refrigerant is used, the refrigeration system must be inspected and certified for the use of that alternate refrigerant. In the case of hydrocarbon refrigerants, this is certified by the Petroleum and Gas Inspectorate
- Any refrigerants may only be charged or drained by persons that are specifically licensed for those refrigerants