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 14, 1980

John Torros, AIA
Division Chief Architect
Bechtel Power Corporation
15740 Shady Grove Road
Gaithersburg, Maryland 20760

Dear Mr. Torres:

This is in response to your request concerning OSHA standards on the minimum size of the access to tanks or pressure vessels. This also confirms a conversation on the subject matter with Mr. Pete Wasko, a member of my staff.

In brief, there are no specific OSHA standards on the minimum size of the access to tanks or pressure vessels beyond the requirements of acceptable good standards of design, such, as may be indicated in the ASME, API, or UL code under which they may have been built as mentioned in such OSHA standards as 29 CFR 1910.106 (b)(l)(iii)(a); 1910.106(b)(l)(iv)(b); 1910.106 (b)(l)(v)(b); 1910.169(a)(2)(i). Copies of these standards are enclosed.

Should you need any further assistance, please feel free to call or write.


Grover C. Wrenn Director,
Federal Compliance and State Programs