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.

July 2, 1976

Mr. Scott T. Carpenter
Senior Safety Representative
EBASCO Services, Ind.
Post Office Box 70
Killona, Louisiana 70066

Dear Mr. Carpenter:

This is in response to your letter dated April 29, 1976, which was forwarded to the National Office for review and comment.

The Divisions of Occupational Safety Programming and Safety Standards have reviewed 29 CFR 1910.106(d)(2)(ii), as it relates to the questions in your letter.

29 CFR 1910.106(d)(2)(ii) is concerned only with emergency venting for portable tanks. More than one type of vent device can be provided, but one must be a pressure-actuated vent with a minimum capacity of 6,000 cubic feet of free air per hour. This time element is taken from table H-O, from the reference to (b)(2)(v)(c). If this pressure-actuated vent provides adequate venting as determined by the reference to (b)(2)(v)(c) or (e), then no other vent is needed. If other vents are needed, however, these may be other than the pressure-actuated vent; i.e., a fusible plug, or even an open pipe vent.

Thank you for your interest in occupational safety and health. If I can be of any further assistance, please feel free to contact me.

Sincerely,



John K. Barto, Chief
Division of Occupational Safety Programming