A worker in a confined space was cleaning demister pads using high-pressure water jetting equipment (jetting gun, lance and pencil nozzle supplied by a water-jetting pump). The worker had taped a torch to the end of the lance because the workspace was dark with poor visibility due to the dispersion of water and particles from the cleaning process.
The worker stood upright, holding the high-pressure water lance between his legs, with the lance facing down and at 90° to the demister pads. The jet of high-pressure water struck his protective gum boot while cleaning the pads.
The force of the water was sufficient to pass through the lining of the boot and penetrate the worker’s foot, creating a high-pressure injection wound that entered and exited through the inner ball of his foot.
Direct causes
- The operating pressure of the water jet greatly exceeded the pressure rating of the protective gum boot worn by the worker.
- The worker pointed the nozzle directly down, within the vicinity of his feet.
Contributory causes
- The pressure setting and water flow rate used during cleaning resulted in twice the recommended reaction force.
Note: A reaction force is created as water leaves the nozzle. This force acts in the opposite direction to the water flow. Exceeding the reaction force makes it more difficult for an operator to control the direction of the water jet. - Personal protective clothing and footwear capable of withstanding the force of the water jet was not worn.
- The torch attached to the lance partially obscured the worker’s vision of the nozzle head and working area.
- There was insufficient lighting for the work task and environment. Intrinsically safe lighting available at the workplace was not utilised.