Question 7 of 7: Accident Case Analysis — Spray-Gun Amputation

Question 7: Accident Case Analysis — Spray-Gun Amputation (20 marks: 6/6/8)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

(i) Cause of the Accident

• Immediate cause — the employee cleaned the clogged nozzle while the gun was still pressurized/energized; the stored pressure released through the tip as it was freed, and the discharge struck the thumb held at the nozzle, causing the severe laceration (with a high-pressure gun, fluid can also be injected into tissue, which is why such wounds so often end in amputation).
• Root/contributing causes: no safe procedure to depressurize/lock out before servicing; inadequate training on the injection hazard and correct clearing method; gun lacked safeguards (trigger lock/guard, automatic pressure relief); clogging from poor filtration/maintenance created the need to intervene.

(ii) Corrective Actions

• Safe procedure (LOTO/depressurization) — shut off, disconnect and relieve pressure before any cleaning; never point at the body.
• Engineering — guns with trigger locks/guards and automatic pressure relief; improve fluid filtration to reduce clogging.
• Training — high-pressure injection hazards (appear minor but are surgical emergencies) and correct unclogging.
• PPE and maintenance — gloves/eye protection; regular servicing schedule.

(iii) Follow-Up

• Investigate and document (root-cause analysis); report the serious injury to the provincial regulator as legally required (e.g., WorkSafeBC in British Columbia), with the joint health and safety committee taking part.
• Implement corrective actions; update the written safe-work procedure; retrain all affected employees.
• Verify effectiveness by inspection/audit; ensure medical care and return-to-work; share lessons across similar operations.