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.

April 18, 1975

Mr. Walter O'Connell
Charles T. Main International, Inc.
Southeast Tower
Prudential Center
Boston, Massachusetts 02199

Dear Mr. O'Connell:

The following is offered in response to your inquiry regarding the requirement to pin or lock digester valves in a closed position throughout the entire cooking period. This is referred to in the Federal Register, page 23753, General Industry Standards, 1910.261(g)(12)(iv), Blowoff Valves and Piping.

The intent of this standard is to protect the employee. Since you plan to operate the valve remotely through automatic controls and monitoring, there would be, as you pointed out in our telephone conversation, no need for employee exposure. Further, due to an unforseen possibility, a special tool would be required to turn the valve and then only after all pressure had been relieved. Because of these considerations, you would be in compliance with the intent of 1926.261(g)(12)(iv). Reference is also made to American National Standard P1.1-1969, Safety Requirements for Pulp, Paper and Paperboard Mills, section 7.12(4).


Gerald M. DuWors
Associate Assistant Regional
Director for Technical Support