Stairway Railings and Guards.[1910.23(d)]

1910.23(d)(1)(i) On stairways less than 44 inches wide having both sides enclosed, at least one handrail, preferably on the right side descending.
1910.23(d)(1)(ii) On stairways less than 44 inches wide having one side open, at least one stair railing on open side.
1910.23(d)(1)(iii) On stairways less than 44 inches wide having both sides open, one stair railing on each side.
1910.23(d)(1)(iv) On stairways more than 44 inches wide but less than 88 inches wide, one handrail on each enclosed side and one stair railing on each open side.
1910.23(d)(1)(v) On stairways 88 or more inches wide, one handrail on each enclosed side, one stair railing on each open side, and one intermediate stair railing located approximately midway of the width.

1910.23(d)(1) Every flight of stairs having four or more risers shall be equipped with standard stair railings or standard handrails as specified in paragraphs (d)(1)(i) through (v) of this section, the width of the stair to be measured clear of all obstructions except handrails: [see 1910,23(d)(1)(i-V)]