(1) Except as provided in Sentence (2) and elsewhere in this Part, materials and components, and their installation, shall conform to the requirements of the applicable standards in Table 5.10.1.1. where those materials or components are,
(a) incorporated into environmental separators or assemblies exposed to the exterior, and
(b) installed to fulfill the requirements of this Part.
(2) The requirements for flame-spread ratings contained in thermal insulation standards shall be applied only as required in Part 3.