Qld Mines Inspectorate investigates workplace incident leaving two unconscious

Investigations continue into the workplace incident which occurred during works on a dragline shutdown and impacted several workers.

The Queensland Mines Inspectorate continues to investigate a workplace incident left two mine workers unconscious in a dragline during a shut down.

Mine sites are being encouraged to review site procedures after a workplace incident left two mine workers unconscious in a dragline during a shut down.

An alarming safety alert released earlier this month exposed the concerning incident.

The Queensland Mines Inspectorate continues to investigate the incident that occurred on April 25 at a Queensland mine, which they declined to identify due to ongoing investigations.

While spray paint was being applied to two separate work fronts inside the revolving frame of a dragline, airborne solvent vapours released by the paint accumulated inside the confined space.

One of the workers who was assisting a spray painter with hose lines was overexposed to the solvent vapours and became unresponsive, Resources Safety and Health Queensland revealed.

The spray painter and another worker had difficulty removing the affected worker from the area, when another spray painter who had previously exited the space, re-entered the confined space to assist with the rescue.

The worker who re-entered the confined space was not wearing any respiratory protection at the time and was also overexposed to the solvent vapours.

They also became unresponsive and required assistance.

Both the affected workers recovered a short time after being removed from the confined space and were relocated outside in fresh air, before being taken to hospital for medical assessment and released a short time later without any diagnosed health effects.

RSHQ revealed there had previously been similar confined space incidents associated with dragline shutdowns and other confined work activities, which required the attention of the mining industry.

The investigation into the most recent incident has found the following matters contributed to the situation:

• Ventilation was not applied to the confined space to dilute or remove airborne contaminants generated by spray painting, although ventilation was identified as a control on the Confined Space Entry Permit and in the Safety Data Sheet (SDS) for the paint product.
• Respiratory protection worn by the affected worker did not provide an adequate level of protection. Although the spray painters wore air-supplied respiratory protection connected to a compressed airline, the hose line assistants used negative pressure half-face respirators with cartridge-style filters. The protection provided by negative pressure respirators is significantly lower than for air-supplied respirators and is dependent on individual facial fit, filter breakthrough capacity and the timely replacement of filters.
• The second worker was not wearing any respiratory protection when they re-entered the confined space to assist with the rescue.
• Personal gas detectors used to monitor atmospheric contaminants inside the confined space were not suitable for detecting the solvent vapours produced by spray painting.
• The confined space entry permit was issued by a worker who was not authorised to issue the permit. The confined space entry permit was issued without inspection of the area to verify that protective controls identified on the permit had been implemented.
• The paint product used at the time of the incident was chosen as a substitute as the paint normally used was not able to be supplied. The substitute product was not approved for use at the mine and the SDS indicated it contained significantly higher proportions of solvent ingredients compared to the other product normally used.

To prevent further similar incidents, all mine site senior executives have been encouraged to:

1. Review site procedures for confined space entry.
2. Ensure persons required to wear respiratory protection have been trained in the selection, use and maintenance of respiratory protection in accordance with AS/NZS 1715-2009. In addition, persons required to wear negative pressure respirators to complete facial fit testing and trained in the limitations and replacement requirements for particulate and gas filter media.
   
3. Ensure ventilation controls are applied to all spray painting tasks to be performed inside confined spaces, irrespective of duration.
4. The selection of gas detectors for use in confined space entry work should consider the type of contaminants likely to be present and cause an exposure risk to workers inside the space.

Investigations into the incident are ongoing and further information relevant to industry is expected to be published as it becomes available.