S.C. Code Ann. § 5-25-890: Stairways; exit doors.

Except in dwellings, no required stairway shall be less than forty-four inches wide and the total width of exit doorways leading therefrom shall at least be equal to the total width of the stairways which they serve. The total width of stairway, interior and exterior, provided for the occupancy of each floor and those above, shall be not less than forty-four inches for the first fifty persons and twelve inches for each additional fifty persons to be accommodated thereby. The stair treads shall be not less than nine and one-half inches wide and the risers not more than seven and three-fourths inches high. Windows in any such required stairway are prohibited. Every hospital and theater over one story high shall have at least two stairways constructed entirely of incombustible material, located remote from each other and continuous from grade line to the topmost story or outside iron fire escapes of approved design. All exit doors in hospitals, theaters and other places of public assemblage shall open outwards.