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Safety

Infection Control

Infection control in the clinical laboratory is a disciplined approach to preventing the transmission of infectious agents to laboratory personnel, the community, and the environment. Unlike clinical care settings where the focus is on patient-to-patient transmission, the laboratory focuses on preventing Laboratory Acquired Infections (LAIs) caused by the manipulation of concentrated pathogens. This safety framework is built upon three pillars: rigorous Risk Assessment, disciplined Specimen Handling, and the use of engineering controls like Biosafety Cabinets

Risk Assessment

This is the foundation of biosafety. It is a systematic process where the laboratory scientist evaluates the intrinsic hazards of the agent (infectious dose, route of transmission, severity of disease) and the procedural hazards (aerosol generation, use of sharps). This assessment determines the appropriate Biosafety Level (BSL-2 or BSL-3) and PPE requirements for the task

Specimen Handling & Standard Precautions

Because any specimen could harbor a lethal pathogen (e.g., HIV, Hepatitis B, or N. meningitidis), all blood and body fluids are treated as if infectious

  • Aerosol Control: The primary hidden danger is the generation of infectious aerosols during centrifugation, vortexing, or pipetting. Use of safety cups and careful technique is mandatory
  • High-Risk Specimens: Suspected TB, fungal cultures, or positive blood culture bottles require enhanced precautions and must be manipulated strictly within containment devices

Biosafety Cabinets (BSC)

The Class II BSC is the primary engineering control in Microbiology. It uses HEPA-filtered laminar airflow to protect the user (from infection), the product (from contamination), and the environment

  • Operation: Users must follow strict protocols (“clean to dirty” workflow, no rapid movements) to maintain the fragile air curtain
  • Limitations: A BSC is not a fume hood; unless it is a Type B2 (total exhaust) unit, it cannot be used with volatile toxic chemicals. It must be certified annually to ensure airflow velocities are sufficient to contain biohazards