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 24, 1975

Mr. Howard Hawley
Tube-Lok Products
P.O. Box 02175
Portland, OR 97202

Dear Mr. Hawley:

In ANSI Standard B56.1-1969, Safety Standard for Powered Industrial Trucks, Section 421 includes the requirement that the overhead guard "shall be capable of withstanding the impact of a 100-pound, solid-hardwood cube (or equivalent) dropped from a distance of 5 feet, 10 times, without fracture or without permanent deflection exceeding 3/4 inch."

You have calculated that a cube of white oak weighing 100 pounds would measure 16 inches on each edge. Obviously, this is not a readily available item and you have suggested the use of a block constructed of laminated wood.

I would consider the laminated block to be an acceptable equivalent for the hardwood block if the following conditions are met:

1. The laminated block must maintain its original size and shape throughout the test procedures.

2. The laminated block shall weigh 100 pounds and shall be of hardwood.

A softwood might provide a cushioning effect which would tend to make the test less severe.


Wesley M. Noble
Acting Associate Assistant
Regional Director, Technical Support