(1) You must make sure each ladder is able to support, without failure, the total of the following loads:

(a) At least two loads of two hundred and fifty pounds each, concentrated between any two consecutive attachments.

(b) Any additional concentrated loads of two hundred and fifty pounds each determined from the anticipated use of the ladder.

(c) Anticipated loads caused by all of the following that apply:

(i) Ice buildup.

(ii) Winds.

(iii) Rigging attached to the ladder, including the load to be lifted.

(iv) Impact loads resulting from the use of ladder safety devices.

(2) You must make sure the design of rails, supports, and fastenings includes:

(a) Live loads to be supported by the ladder; and

(b) The weight of the ladder and everything attached to it.

(3) You must consider all live loads to be concentrated at the point or points that will cause the maximum stress on the ladder or structural member.

(4) You must make sure each step or rung is capable of supporting a single concentrated load of at least two hundred fifty pounds applied in the middle of the step or rung.

(5) You must make sure the design stresses for wood components of ladders meet the requirements and specifications of ANSI A14.1, American National Standard for Ladders-Portable Wood-Safety Requirements, in effect when the ladder was installed.

(6) You must make sure fastenings are designed to meet the ladder load requirements.