(1) Ladders must be used to enter and exit manholes exceeding four feet in depth.

(2) Metal and fiberglass manhole ladders must be free of structural defects and free of accident hazards such as sharp edges and burrs. The metal must be protected against corrosion unless inherently corrosion-resistant. These ladders may be designed with parallel side rails, or with side rails varying uniformly in separation along the length (tapered) or with side rails flaring at the base to increase stability.

(3) The spacing of rungs or steps must be on twelve-inch centers.

(4) Connections between rungs or steps and side rails must be constructed to ensure rigidity as well as strength.

(5) Rungs and steps must be corrugated, knurled, dimpled, coated with skid-resistant material, or otherwise treated to minimize the possibility of slipping.

(6) Ladder hardware must meet the ladder's component parts and must be of a material that is protected against corrosion unless inherently corrosion-resistant. Metals must be so selected as to avoid excessive galvanic action.