What Happened?

While extracting bone marrow from an infected mouse, a student inserted a needle into the narrow end of the bone and attempted to flush the marrow into a centrifuge tube. Using excessive force, he caused infected bone marrow to splash directly into their eye. The student was wearing gloves and a lab coat, but no eye protection. They immediately stopped work, flushed both eyes at the eyewash station for 15 minutes, and reported the incident to the lab manager, who directed them to the Occupational Health and Safety Facility for evaluation.

What Was The Cause?

• Immediate cause: Infectious bone marrow was ejected from an open centrifuge tube during needle-flushing and contacted the student's unprotected eye.
• Underlying causes: Hazard recognition gap, missing controls, and technique-level error
  • Eye protection was not worn for a splash-generating procedure on infectious material.
  • The procedure was performed on the open bench rather than in a biosafety cabinet or behind a splash shield.
  • Flushing technique was not controlled — excessive force amplified the splash.
• Root cause: Gap in the lab's hazard assessment, SOP, and training for bone marrow extraction from infected animals — specifically, failure to identify marrow flushing as a splash-generating step requiring mucous-membrane PPE and/or containment, and failure to enforce PPE and technique standards before the student began the procedure.
• The good part: The student immediately used the eyewash station and flushed for 15 min. They then directly reported the incident to their supervisor.

How Can Incidents Like This Be Prevented?

• Contain the splash. Perform all extractions from infected animals inside a biosafety cabinet, or behind a benchtop splash shield if a BSC is unavailable.
• Change the technique. Switch to centrifugation-based marrow extraction or, if flushing is required, use blunt/filter needles and a closed receptacle with slow, controlled pressure.
• Protect the face, not just the hands. Require goggles or a face shield, not just safety glasses, for any splash-prone work with infectious material. 
• Train before the bench. No work with infected animals until BBP training, SOP walkthrough, and a supervised first performance are complete and documented.
• Close the loop. Complete institutional post-exposure evaluation, report to the Biosafety Officer, and add this incident to onboarding and annual refresher training.

Resources

• Risk Group Classification for Infectious Agents
• Pathogen Safety Data Sheets