From NEC Section 505.7(B)

(B) Dual Classification. In instances of areas within the same facility classified separately, Class I, Zone 2 locations shall be permitted to abut, but not overlap, Class I, Division 2 locations. Class I, Zone 0 or Zone 1 locations shall not abut Class I, Division 1 or Division 2 locations.

The area immediately adjacent to a Zone 0 area is generally Zone 1, and the area immediately adjacent to a Zone 1 area is generally Zone 2, and these classifications cannot be replaced by division-classified areas, thus Division 1 or 2 areas may not abut Zone 0 or 1 areas

NOTE: This is an unformatted excerpt from our online fire protection training library.