Hydraulic sample extruder – finger laceration

What happened?

Whilst using a hydraulic sample extruder in a laboratory, the technician caught and injured his finger between the Shelby tube and extruder ram while trying to stabilise the dolly.  The incident resulted in a lost workday case.

What were the causes? What went wrong?

The investigation identified the following contributing factors:

  • Training – insufficient task training and competence assessment;
  • Supervision – ineffective supervision;
  • Risk Assessment – the task risk assessment did not consider the equipment limits and functions or advances in technology, therefore not all the hazards and associated risks were identified or controlled;
  • Design – the sample extruder design is dated and does not consider human factors or ergonomics;
  • Line of Fire – the technician placed his hand between the moving hydraulic sample extruder ram and Shelby tube.

Lessons learned

  • Employee training and competence assessment, together with the appropriate level of supervision, is essential;
  • Risk assessments and work instructions should be current and periodically reviewed to take account of new information, changes in technology and legislation;
  • A standardised hydraulic sample extruder design / type and use would be central to the reduction of incidents of this sort.


  • Improved employee training, competence management and supervision requirements;
  • Reviewed and revised equipment and task risk assessments;
  • Improved signage and labelling, start/stop controls and added guard for moving parts / shear point;
  • Standardised hydraulic sample extruder design / type and use across the company;
  • Develop common operating procedures for this equipment.