Equipment separation is the practical control
The risk in a mixed building is transfer. A mop that has been over an oily slab, a cloth that has wiped a dock threshold, or a vacuum used on both floors moves industrial soil into a room where people eat. It is not a theoretical concern, and it is entirely preventable by allocating separate equipment and storing it separately. The same applies to a vacuum used on both a slab and an office carpet.
That allocation belongs in the scope rather than in a crew's habit, because habits do not survive staff changes. Colour coding is the usual method and it works well when it is written down and inducted. It also gives a site something to check: if the same mop bucket is in the lunchroom and the warehouse, the arrangement has slipped and somebody can say so.
