Alert no. 469 | 30 January 2026 | Version 1

Fluid injection whilst using a cordless grease gun

What happened?

• A coal mine worker was recently injured at an open cut coal mine in Central Queensland, while servicing a light vehicle inside the mine’s workshop.
• The worker was lubricating the leaf spring bush assembly on the vehicle using an 18V cordless grease gun. The grease pump hose then failed next to the grease coupler, resulting in sudden release of energy which caused a grease injection injury to the worker’s left thumb.
• Minimum safety requirements for the cordless grease gun were not met. Further learnings are outlined below.

How did it happen?

• The cordless grease gun used by the worker was fitted with a modified flexible grease hose that did not meet the minimum safety factor requirements specified in Recognised Standard 23 – Fluid power safety in coal mines for hoses and adaptor fittings (RS23), specifically relating to Section 8.5.2 -Fluid component safety factors (stating hose assemblies should have a safety factor of at least 4:1).
• The installed hose had an assessed safety factor of approximately 1.2:1, based on a maximum working pressure of 10,000 psi. The hose failed at the connection between the hose and fitting at the coupler end of the assembly, at a known stress and kink point (Figure 1).Figure 1 - The hose failed at the connection between the hose and fitting at the coupler end of the assembly.

• The modified grease hose was not fitted with spring guards at either end. Spring guards are designed and fitted to prevent hose kinking and to improve the strength and security of the connection between the hose and metal coupling, thereby reducing the risk of hose failure when operating under high pressure.
• The mine’s ‘Management of Change’ process was not applied to the replacement or modification of the hose on the cordless grease gun. As a result, maximum working pressures were not assessed or verified, and the replacement hose was not confirmed as compliant with the minimum safety factor requirements for hoses and fittings specified in RS23.
• Based on information provided by the original equipment manufacturer (OEM), the grease hose originally fitted to the cordless grease gun when purchased new is tested during manufacture to a 2:1 safety factor. The hose assembly supplied by the OEM is not tested or verified to meet the 4:1 safety factor required under RS23.
• The gloves worn by the injured coal mine worker (Figure 2) for the assigned task were certified to EN388 (4131X) and EN407 (X1XXXX). However, these standards assess mechanical and thermal performance only and do not address protection against high-pressure fluid injection, which is a specialised hazard requiring dedicated testing and controls.

Figure 2 - The gloves worn by the injured coal mine worker did not address high-pressure fluid injection risks.

Recommendations

Following this incident, all Site Senior Executives (SSEs) should take action to ensure associated risks are appropriately mitigated, noting the circumstances of this incident. Steps include:

• Discontinue the use of all cordless grease guns until compliance with fluid component safety factors for hoses and fittings are verified in accordance with RS23.
• Ensure that all manually operated and battery-powered grease guns currently in use at their mine, along with similar fluid power equipment, are audited and subject to a gap analysis against RS23.
  • In addition, the site’s planned inspection and preventative maintenance schedules are to be reviewed and updated to ensure that high-pressure hoses on grease guns and comparable fluid power equipment are incorporated into a whole-of-life cycle maintenance strategy.
• Review contractor management and site acceptance procedures to ensure that all hydraulic tooling supplied to and used at the mine complies with RS23.
• Audit the mine’s Emergency Response Plan and First Aid Management Plan to assess the effectiveness of controls for managing high-pressure fluid injection injuries, with reference to RS23, including the emergency procedure requirements and Appendix F: Emergency Response Plans – High-Pressure Fluid Injection.
• Review the personal protective equipment (PPE) provided to coal mine workers who may be exposed to high-pressure fluid injection hazards and consult with glove manufacturers or suppliers to identify and procure gloves specifically designed to provide protection against high-pressure fluid injection risks.

References and further information

• Safety Alert #440 – Fluid injection into CMW’s skin
• Recognised Standard 23: Fluid power safety in coal mines (Gazetted 27 August 2021)
• Safety Bulletin 139: Risk management of high-pressure fluids and gases
• Safety Alert 271: Longwall fluid-injection injury
• Safety Bulletin 67: Managing high-pressure fluids and gases
• Coal Mining Safety and Health Regulation 2017 - (Chapter 4, Part 4, Section 149 - Principal hazard management plan)