National Code

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) 

Washington DC Code

2014 District of Columbia Code Division I. Government of District Title 6. Housing and Building Restrictions and Regulations Chapter 7. Fire Safety Subchapter I. General Part A. Fire Escapes, Elevators, Stairways, Etc § 6–701.03. Duty of owner to provide fire safety measures.

Universal Citation: DC Code § 6–701.03. (2014) 

It shall be the duty of the owner entitled to the beneficial use, rental, or control of any building used or intended to be used as set forth in § 6‑701.01 where fire escapes are required, or any building in which 10 or more persons are employed, as set forth in § 6‑701.02, where fire escapes are required, also to provide, install, and maintain therein proper and sufficient guide signs, guide lights, exit lights, hall and stairway lights, standpipes, fire extinguishers, and alarm gongs and striking stations in such locations and numbers and of such type and character as the Mayor of the District of Columbia may determine; except that in buildings less than 6 stories in height, standpipes will not be required when fire extinguishers are installed in such numbers and of such type and character as the Mayor of the District of Columbia may determine.