Pass Box

A static pass box is a non-powered transfer chamber used in cleanrooms to move materials from one room to another without cross contamination or pressure imbalance. Two interlocked doors allow only one door to open at a time, which prevents air from one area entering the other and keeps differential pressure stable. The enclosure is typically fabricated from SS 304 with smooth, easy-to-clean surfaces, flush glazing, and high-integrity gaskets to minimize particle traps. Standard features include mechanical or electromagnetic door interlocks, viewing window, indicator lights, and an audible buzzer. Optional UV germicidal light with a safety interlock can be provided for added hygiene during idle periods. Static pass boxes are suited for pharmaceuticals, hospitals, and laboratories where safe, clean transfer of packaged items is required.

A dynamic pass box is a forced-air transfer chamber used to move materials between rooms while preventing airborne cross contamination. Installed between areas of different cleanliness classes, it uses a blower with prefilters and a HEPA filter to purge the chamber and deliver clean laminar airflow before the receiving door is released. Door interlocking ensures only one door opens at a time, protecting pressure differentials and blocking contaminants from the non-sterile side. A differential pressure gauge monitors filter loading and chamber pressure, while indicator lights and an audible buzzer show cycle status. The unit is typically SS 304 with smooth, easy-to-clean interiors, gasketed vision doors, and options such as UV germicidal light with safety interlock, EC or VFD-controlled blower, and hour meter for maintenance tracking.