2012 IFC 1104.16.5.1 Fire escape stairs must be examined every 5 years ,by design professional or others acceptable and inspection report must be submitted to the fire code official.

IBC 1001.3.3 All fire escapes shall be examined and/or tested and certified every five years by a design professional or others acceptable who will then submit an affidavit city official.

NFPA LIFE SAFETY CODE 101  7.2.8.6.2 The Authority Having Jurisdiction (AHJ) shall approve any fire escape by Load Test or other evidence of strength (Certification).

OSHA 1910.37 Exit routes must be maintained during construction, repairs, alterations or provide alternative egress with equivalent level of safety. (permit issued if egress is certified or with egress scaffolding)