In addition to the walking-working surface rule (WAC 296-24-73505) requirements, and the relevant fixed ladder standard requirements in this chapter, you must ensure:

(1) Each step bolt installed on or after October 1, 2020, in an environment where corrosion may occur is constructed of, or coated with, material that protects against corrosion.

(2) Each step bolt is designed, constructed, and maintained to prevent the employee's foot from slipping off the end, or side edge, of the step bolt.

(3) Step bolts are uniformly spaced at a vertical distance of not less than twelve inches (30 cm) and not more than eighteen inches (46 cm) apart, measured center to center (see Figure D-6 of this section). The spacing from the entry and exit surface to the first step bolt may differ from the spacing between the other step bolts.

(4) Each step bolt has a minimum clear width of four and one-half inches (11 cm).

(5) The minimum perpendicular distance between the centerline of each step bolt to the nearest permanent object in back of the step bolt is seven inches (18 cm). When the employer demonstrates that an obstruction cannot be avoided, the distance must be at least four and one-half inches (11 cm).

(6) Each step bolt installed before October 1, 2020, is capable of supporting its maximum intended load.

(7) Each step bolt installed on or after October 1, 2020, is capable of supporting at least four times its maximum intended load.

(8) Each step bolt is inspected at the start of the work shift and maintained in accordance with the walking-working surface rule (WAC 296-24-73505).

(9) Each step bolt installed before October 1, 2020, is capable of supporting its maximum intended load.

(10) Each step bolt installed on or after October 1, 2020, is capable of supporting at least four times its maximum intended load.

(11) Each step bolt is inspected at the start of the work shift and maintained in accordance with the walking-working surface rule (WAC 296-24-73505).