PTCB Certified Pharmacy Technician (PTCE)MedicationsMedium

A pharmacy technician is preparing a compounded sterile product in a laminar airflow workbench (LAFW). Which of the following describes the appropriate airflow pattern within the LAFW?

  1. AAir flows vertically from the top of the hood to the work surface.
  2. BAir flows from the sides towards the center of the work surface.
  3. CAir flows vertically from bottom to top.
  4. DAir flows horizontally from the back of the hood to the front.
Show answer & explanation

Correct answer: D. Air flows horizontally from the back of the hood to the front.

A horizontal laminar airflow workbench (LAFW) provides a continuous stream of HEPA-filtered air moving horizontally from the back of the hood across the work surface and out towards the operator, protecting the product from contamination.

Why the other options are wrong

  • A. This describes a vertical LAFW, also known as a biological safety cabinet (BSC), not a horizontal LAFW.
  • B. This flow pattern would not effectively maintain sterility and could draw contaminants inward.
  • C. This is not characteristic of a standard LAFW, which typically has horizontal or vertical flow from top/back.

Laminar Airflow Workbench (LAFW)

A LAFW is a primary engineering control that provides a unidirectional, HEPA-filtered airflow to protect sterile products from particulate and microbial contamination during compounding.

  • Can be horizontal or vertical flow.
  • Horizontal LAFWs protect the product only.
  • Vertical LAFWs (BSCs) protect product, personnel, and environment.

Memory trick: Laminar flow means 'smooth, clean air movement'.

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