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.

May 21, 1992

Mr. Bill Skillern
Sales Manager
Trench Plate Rental Co.
13217 Laureldale
Avenue Downey, California 90242

Dear Mr. Skillern:

This is in response to your April 7 letter requesting an interpretation of Occupational Safety and Health Administration (OSHA) standards addressing the design of protective systems for employees working in trenches.

Without discussing the engineering specifies of the data contained in your table, please be advised that the Speed-Shore C-60 table does meet the intent of OSHA's regulations, under the options set forth in both 29 CFR 1926.652(c)(2) and (c)(3). These options are discussed in the enclosed FEDERAL REGISTER of October 31, 1989 (FR 45931). While the C-60 soil classification does not exist in the OSHA soil classification system found in Appendix A to Subpart P, it appears that the manufacturer has met the requirements of 1926.652 in that the tabulated data has been approved by a registered professional engineer and provides, in writing, the information necessary to safely use the tables.

Your letter indicates that you are operating in the State of California, which oversees its own safety and health program. While your tables meet the intent of the Federal regulations, they may not be adequate to meet the California provisions which can impose additional requirements. You may wish to contact California OSHA (CalOSHA) at (415) 703-4590.

If we can be of any further assistance please contact Mr. Roy Gurnham or Mr. Dale Cavanaugh of my staff in the Office of Construction and Maritime Compliance Assistance at (202) 523-8136.


Patricia K. Clark, Director
Directorate of Compliance Programs