LimsPulse
Microbiology & sterility

Laminar air flow unit (LAF)

A work station that blows HEPA-filtered air in a uniform, one-directional stream over the work surface to give an ISO 5 / Grade A zone for aseptic handling of media, samples and sterile materials.

  • Pharmaceutical
  • Biotech
  • Hospitals and compounding pharmacies
  • Electronics
  • Food & beverage
  • Research laboratories
Photo of a Laminar air flow unit (LAF)
Photo: Hugh Fox, CC BY-SA 2.0 (cropped), via Wikimedia Commons
Follow your site SOP
This is a typical operating sequence for learning. Your instrument model and approved SOP take precedence.
STAGE 1

Before you start

  1. 1Check the LAF is within its qualification due date (air velocity, HEPA integrity and particle count) and has no 'out of order' label.
  2. 2Switch off the UV lamp if it was on, and do not look at it directly.
  3. 3Switch on the blower and let it run for the time defined in your SOP (commonly 15–30 minutes) before use.
  4. 4Check the differential pressure gauge reading is within its normal range and record it.
  5. 5Clean the work surface and inner side walls with a sporicidal or approved disinfectant, followed by sterile 70% IPA, wiping from the back to the front.
  • UV light damages eyes and skin. Never work in the LAF with the UV lamp on.
STAGE 2

Working in the LAF

  1. 1Wear the garments and sterile gloves required by your SOP; sanitise gloves before entering the work zone.
  2. 2Take in only the items needed for the task, after wiping them with 70% IPA.
  3. 3Arrange items so that first air reaches open containers and plates without passing over hands or other objects.
  4. 4Work at least about 15 cm inside the front edge and keep movements slow and deliberate.
  5. 5Expose settle plates or use contact plates for environmental monitoring during the session as per your SOP.
  • Do not block the front air grille or the HEPA filter face.
  • Avoid rapid arm movements, talking over open plates and placing large objects upstream of the work.
STAGE 3

After use

  1. 1Remove all materials and discard waste in the correct biohazard container.
  2. 2Clean the work surface and walls with disinfectant, then 70% IPA.
  3. 3Let the blower run for a few minutes, then switch it off as per your SOP (some units run continuously).
  4. 4Switch on the UV lamp for the set time if your SOP requires it.
  5. 5Complete the LAF usage and cleaning log.
In LimsPulse · Calibration Management

Keep every LAF in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.

See how