OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.



June 4, 1991





SUBJECT: Acceptability of Portable Hook Ladder to Secure a Lanyard


This is in response to your three memorandums dated September 10, 1987, February 28, 1989, and February 27, 1991 requesting a determination of the acceptability of securing personal fall arrest lanyards to portable hook ladders. The needs of your Region on this issue were discussed in a telephone conversation between Janice Barrier of your staff and Rolland Stroup of my staff on April 9, 1991. We are truly sorry for the extreme delay in this written response.

The information provided to you by the Raymond G. Osborne Laboratories, Inc., on the test conducted is insufficient for a determination to be made that the securing of a personal fall arrest lanyard to a portable hook ladder is a safe thing to do. At a minimum, the following deficiencies would have to be addressed, before we could reconsider the matter:





  1. The test that was conducted to determine the ability of 13'-0" aluminum hook ladder and safety line assembly to withstand the force of arresting 350 pounds weight after a 4'-0" free fall is not compatible with protection required by the General Duty Clause in section 5(a)(1) of Occupational Safety and Health Act. These requirements may be found in the proposed 29 CFR 1910, Walking and Working Surfaces and Personal Protective Equipment (Fall protection Systems), Subpart I, or in 29 CFR 1910.66, Powered Platforms for Building Maintenance, Section I of Appendix C.
  2. No information was provided on the ability of the entire system, which would include the billboard, to withstand the impact force applied to it. The test was conducted with the ladder hanging vertically and the hook assembly over a four-inch box section, not on a billboard with the side rails outboard of the platform at an angle to the sign face.
  3. No information was provided on the ability of aluminum portable hook ladders to stay in place during and right after arresting force at different angles of fall.


[Corrected 4/4/2005.

Note: On April 10, 1990 OSHA published proposed revisions to Walking and Working Surfaces; Personal Protective Equipment (Fall Protection Systems); Notices of Proposed Rulemaking; Slips; Falls;Trips in
Federal Register 55:13360-13441. It is available electronically only as an abstract. On May 2, 2003 OSHA reopened the rulemaking record on the proposed revisions to Walking and Working Surfaces and Personal Protective Equipment (Fall Protection Systems). It was re-published in its entirety in Federal Register 68:23527-23568 and is available electronically.]