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.

MAR 7 1991

Mr. Richard N. Hill
Florida Swing Stage Corp.
6112 Topher Trail
Mulberry, Florida 33860

Dear Mr. Hill:

This is in response to your letter of September 20, 1990, to Mr. Pat Cattafesta regarding your concern, as a manufacturer, about complying with the requirements of 29 CFR 1910.66(f)(3) (i)(c) in the powered platform standard. This provision states that "the initiation of a traversing movement for a manually propelled carriage on a smooth level surface shall not require a person to exert a horizontal force greater than 40 pounds (444.8 n)." We apologize for the delay in our response.

In your phone conversation of October 4, 1990, with Mr. Cattafesta, you indicated that you lacked the engineering resources to redesign your equipment to meet the above requirement. Unfortunately, the Occupational Safety and Health Administration's consultation program is not funded to respond toe ngineering assistance requests from manufacturers.

This office, however, can offer some suggestions which you may consider in addressing your problem. First, it is unlikely that the average window washer would be able to generate one hundred pounds of force to overcome the initial inertia of the carriage. Since you claim that employees are moving the roof carriage now without injury, it is quite possible they are generating less than one hundred pounds of force per person. Therefore, your first step is to determine the actual force generated by those employees in the initial movement of the carriage. You may find that the force is less than one hundred pounds, but greater that forty pounds.

Second, once you have determined the amount of excess force over forty pounds being generated, you should take the necessary steps to reduce it to forty pounds. One method to accomplish this might be to increase the wheel radius on the roof carriage. Since the radius of these wheels is similar to the moment arm of a lever, any increase in wheel radius would increase the mechanical advantage that can be obtained. Therefore, a proper wheel radius should help reduce the force necessary to move the roof carriage.

We appreciate your interest in the safety and health of employees.


Patricia K. Clark, Director
Directorate of Compliance Programs