A pass box is a small chamber fitted through the wall between two areas. Material goes in from one side and is taken out from the other, so staff do not have to walk between rooms and the clean area’s doors stay closed. There are two types, and the right choice depends on the cleanliness of the rooms on either side.
Static pass box
A static pass box has no fan or filter. It is a sealed stainless steel or powder coated chamber with a door on each side, often with a UV light to treat the inside surfaces between transfers. It suits transfers between two areas of the same or similar cleanliness class, where the main goal is to avoid opening a full-size door.
Dynamic pass box
A dynamic pass box adds a motor-blower and a HEPA filter. Filtered air sweeps the chamber, so particles carried in with the material are flushed out before the inner door is opened. Our dynamic pass boxes use an EU 4 pre-filter, an EU 7 intermediate filter and an EU 14 HEPA supply filter, with a DOP test port and a differential pressure gauge for validation and monitoring.
How to choose
- Same class on both sides: a static pass box is usually enough.
- Moving from a lower class into a higher class: choose a dynamic pass box so the chamber is purged with filtered air.
- Material of construction: SS 304 is common; SS 316 / 316L is chosen where cleaning agents or the process demand it. GI powder coated is an economical option for less demanding areas.
What to tell us when you enquire
Share the wall thickness, the inner size you need, the cleanliness of both rooms and your preferred material. We build both types to size — see the static pass box and dynamic pass box pages for specifications.
