ANSI A64.1 : 1968

Gives specifications for the safe design and construction of fixed stairs including interior and exterior stairs around machinery, tanks, and other equipment, and stairs leading to or from floors, platforms, or pits. It does not apply to stairs used for fire exits, construction operations, private residences, articulated stairs, on floating roof tanks or on docks, the angle of which changes with the rise and fall of the base support.