German to English Tech/Engineering Medical: Pharmaceuticals Cleanroom manufacturing of pharmaceuticals

Context is a standard operating procedure document for entering and exiting a pharmaceutical cleanroom.

This one really has me stumped. No dictionary seems to have it, not even a German cleanroom glossary. Google searches only turn up grill equipment... maybe they're making Döner in these cleanrooms? Spieß- means "skewer" and "Kasten" is box, does anybody know of a cleanroom apparatus that might look like this? The term only occurs once in all the documentation:

Für alle Tätigkeiten in der Reinraumzone B kann der blaue Overall verwendet werden (Bsp. Wechsel des Spießkastens).

Many thanks to anyone who can shed some light on this!