FOREWORD The Ventilated Pass Box equipments works to transfer material between areas with different cleanliness grade. The materials may cross the Pass Box in both directions by different handling operations through two interlocked doors. The basic unit can be variously featured with sterilization or decontamination cycle ( like germicidal lamps or hydrogen peroxide decontamination or sterilization mode ) to deliver the appropriate cleaning procedure according to the application to be performed. OPERATING PRINCIPALS A double inlet centrifugal motor-blower provides a vertical airflow in the pass-trough chamber with two interlocked doors. The “contaminated” air coming from the chamber, is aspirated by the motor-blower from the two side duct walls and then re-circulated through an HEPA filter. Part of the re-circulated air is exhausted in the not clean side (NCS) by means of an outlet located on the upper front wall, so the pressure inside the pass box is lower than the ones in the clean and dirty side.