Laminar Airflow Hood Operation and Maintenance

Types of Laminar Airflow Hoods

Horizontal laminar airflow workbenches (LAFWs) blow HEPA-filtered air horizontally from the back toward the operator. These are used for most sterile compounding. Vertical (biological safety cabinets or BSCs) blow air downward and are required for hazardous drugs and chemotherapy compounding.

The HEPA filter removes 99.97% of particles 0.3 microns or larger. The hood must run for at least 30 minutes before use to establish proper airflow patterns and should be cleaned with sterile 70% isopropyl alcohol before each compounding session.

Proper Technique Inside the Hood

Work at least 6 inches inside the hood to ensure items are within the zone of first air. Never block airflow between the HEPA filter and the critical site. Arrange supplies so that larger items are positioned downstream from smaller items to avoid disrupting airflow.

Clean the hood by wiping from back to front and from the cleanest area to the dirtiest, using overlapping strokes with sterile 70% IPA on lint-free wipes.

Exam Preparation

Hood operation questions are common on the PTCB exam. Review procedures with PTCB flashcards and practice with mini exams.