WAC 296-876-40015. Support

(1) You must place the ladder either: (a) With a secure footing on a firm, level support surface; or (b) Secure the ladder to prevent accidental displacement. (2) You must make sure a ladder is not placed on ice, snow, or other slippery surface unless the ladder is prevented from accidental displacement by either: (a) Securing it; or (b) Providing the ladder with slip-resistant feet. Note: Slip-resistant feet are not a substitute for care in placing, lashing, or holding a ladder that is used on a slippery surface. (3) You must make sure ladders are not placed on boxes, barrels, or other unstable bases to obtain additional height. (4) You must place a straight ladder so the side rails are equally supported by the top support, unless the ladder is equipped with a single support attachment. (5) You must make sure the top support of the ladder is reasonably rigid and able to support the load.