A worker was using an angle grinder to cut the top section off a 1,000 litre plastic intermediate bulk container (IBC) when chemical vapours ignited causing serious burns.
The safety incident occurred at the processing plant of Northparkes mine on 4 April 2023.
The NSW Resources Regulator has commenced an investigation to determine the cause and circumstances of the incident.
Contract workers were undertaking maintenance work at the mine’s processing plant as part of a planned shutdown.
To facilitate the removal of waste product from the processing plant, workers obtained what they believed to be empty IBCs from a nearby storage area and cut the top portion off the container so that they could be used as waste bins.
A forklift operator retrieved a 1000 litre plastic IBC, which was supported by an external aluminium cage like frame, from a nearby storage area and placed it an open area outside the processing plant. It had not been cut and appeared to be empty.
The IBC bore a label indicating the product that had been stored in it was Fisherchem C503, a caustic alkali liquid used as a flotation reagent.
The product is classified as dangerous goods and is a hazardous chemical in accordance with the Globally Harmonised System of Classification and Labelling of Chemicals (GHS).
The products label contained GHS pictograms indicating that the product was an environmental and corrosive hazard.
A crane operator involved in the maintenance work obtained an angle grinder and began cutting the top of the IBC.
A short time later workers in the area reported hearing a rush of air and a loud bang and observed the worker laying on the ground several metres from the IBC.
The angle grinder that the worker had been using was also on the ground a short distance from him.
The worker was pulling at his shirt, which was smouldering.
Several nearby workers removed the worker’s shirt and requested assistance.
Responders saw the worker had suffered burns to his arms and face and rendered first aid before the worker was transported to hospital for specialist burns treatment.
Safety recommendations for mine operators and contractors include:
the implementation of a hot work permit system requiring all potential hazards associated with cutting containers and drums to be identified and controlled
identification and control of all risks (including physical or chemical reaction) in relation to the use, handling and storage of hazardous chemicals, having regard to the products safety data sheets
ensuring that containers previously used for the handling and storage of hazardous chemicals are appropriately cleaned and are free of such chemicals (including residues and vapours) when they cease being used for that purpose.
In particular, workers must:
refer to and consider product safety data sheets when undertaking tasks involving the use, handling or storage of hazardous chemicals, including the repurposing of chemical storage containers
be aware that liquids and vapours not classified as flammable, may ignite upon contact with a heat source
ensure they comply with mine operators’ hot work procedures, hazard identification and risk management processes, and inform supervisors whenever hazardous conditions are encountered or task procedures have changed from those originally planned.