To limit the probability that wall and ceiling finishes that have inappropriately high flame-spread ratings will be used in certain passageways that provide means of egress, which could lead to the spread of fire across the exposed surfaces of the finishes, which could lead to a delay in evacuation, which could lead to harm to persons.
To exempt interior wall finishes in exterior exit passageways [that provide the only means of egress from the rooms or suites they serve] from the application of Sentence 3.1.13.2.(1).