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 http://www.osha.gov.

June 24, 2002

Mr. J. Robert Harrell
Safety Management Services
44012 Santa Nella Place
San Diego, CA 92130-2291

Re: §1926.452(w)(2), 1926.452(w)(3), and 1926.452(w)(6)(iv); mobile scaffolds

Dear Mr. Harrell:

This is in response to your December 26, 2001, and April 8, 2002, letters addressed to the Occupational Safety and Health Administration (OSHA) and a subsequent phone conversation with a member of my staff, Mr. Steve Stock. We apologize for the delay in responding to your request.

Question: The issue you raise concerns an OSHA interpretation letter regarding whether OSHA construction standards allow employees to stay on a certain type of scaffold with the casters in the unlocked position. This issue was addressed in OSHA's letter to Mr. Douglas Holman on June 8, 1998. The type of scaffold in question is commonly referred to as a "Perry" or "Baker" scaffold. Specifically, you assert that the guidance we provided in the letter is contrary to the manufacturers' instructions on their use and is not safe. In your April 8 letter and telephone conversations with my staff, you have submitted court documents and have described two accidents that you assert are illustrative of your assertion.

Response: From the June 8, 1998 letter to Mr. Holman

In the Holman letter, we stated:

Your questions related specifically to Baker style scaffolds and whether a person could move and work from this type of scaffold without dismounting, with the casters in the unlocked position. We apologize for the delay in this response.

Baker scaffolds, sometimes referred to as Perry scaffolds, are covered by the mobile scaffold section of subpart L. Section 1926.452(w)(2) requires the casters and wheels to be locked when in use. If a device were installed to permit the casters to be locked while on the scaffold, this requirement could be met without dismounting.

Section 1926.452(w)(6) specifies the requirements for riding a scaffold. Where these conditions are met, the scaffold may be moved while employees are on it.

You asked for clarification on sections 1926.452(w)(3) and 1926.452(w)(6)(iv). These sections address the manual and powered forces used to move the scaffold. When manually moving the scaffold, the force should be applied as close to the base a practicable, but not more than 5 feet (1.5m) above the supporting surface. Your letter describes a worker standing on a Baker scaffold that is 2 to 4 feet high. The worker holds onto something overhead and moves the scaffold with his or her feet. Since the force being applied to the scaffold is less than 5 feet from the ground level, this is acceptable as long as it is the lowest point practicable. When using a power system to move the scaffold, the forces must be applied directly to the wheels. (This section would not apply to workers manually moving a scaffold.) [Emphasis added.]


As we explained in the Holman letter, 1926.452(w)(2) requires that mobile scaffold casters and wheels be locked to prevent scaffold movement when in use. If a device were installed to permit the casters to be locked while on a scaffold, this particular requirement could be met without dismounting the scaffold. However, there are other requirements that must be met where an employee is on (and moves) a scaffold, and they must be met as well. Section 1926.452(w)(3) and 1926.452(w)(6)(iv) address the manual and powered forces used to move the scaffold. Section 1926.452(w)(6) specifies requirements for moving a scaffold while an employee is on it.

One of those requirements is §1926.452(w)(6)(i):

"The surface on which the scaffold is being moved [must be] within 3 degrees of level, and free of pits, holes, and obstructions."

We will not comment on the particular accident cases you refer to, since it would be inappropriate for us to attempt to assess facts involved in private litigation. However, for illustrative purposes, we will comment on two hypothetical scenarios: one in which there is debris in the path of the scaffold, and another in which there is a cover over a floor opening, and the cover is either raised above or depressed below the floor surface.

In both scenarios, the requirement that the floor area be free of obstructions is violated. In the first scenario, the floor is not clear of debris. In the second scenario, the cover interferes with/disrupts the scaffold's movement. Such conditions would violate the procedure explained in the Holman letter. In both scenarios, the employees would have to dismount before the scaffold was moved to be in compliance with OSHA requirements.

The next issue is as follows: if moving a scaffold with an employee on it is contrary to the scaffold manufacturer's instructions, is such a practice prohibited by OSHA requirements? You have submitted a copy of a letter from a manufacturer indicating that having an employee move a scaffold while on it is contrary to the manufacturer's instructions. That letter points out two reasons for the company's policy: (1) encountering an obstruction can cause the rider to be thrown from the scaffold, and (2) the scaffold was not designed to withstand the loads imposed by an employee moving the scaffold while on it.

There is no general provision in the standard requiring that manufacturer instructions be followed. However, note that there are requirements in the standard that address both points raised in the manufacturer's letter. Regarding the first point, as discussed above, the standard prohibits an employee from being on a moving scaffold if there is an obstruction in the path of the scaffold.

Regarding the second point, under §1926.451(a)(1), "each scaffold and scaffold component shall be capable of supporting, without failure, its own weight and at least 4 times the maximum intended load applied or transmitted to it." Under §1926.451(f)(1), "scaffolds and scaffold components shall not be loaded in excess of their maximum intended loads or rated capacities, whichever is less." Therefore, OSHA requirements prohibit a scaffold from being used in a way that would exceed these load restrictions. If having an employee move a scaffold while on it would result in a violation of the load restriction requirements, such a practice would be prohibited by the standard.

Finally, you ask about potential liability in private party lawsuits where an employer uses a scaffold in a manner that accords with OSHA requirements but is contrary to the scaffold manufacturer's instructions. Those are questions that are beyond the purview of this office. We can only observe that court decisions in private litigation differ widely regarding the extent to which compliance or non-compliance with OSHA standards is treated as relevant.

If you need additional information, please contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Guidance, fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.


Russell B. Swanson, Director
Directorate of Construction

[Corrected 6/2/2005]