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.

February 23, 1973

Mr. Robert I. Slaughter
Safety Supervisor
Chicago Bridge & Iron Company
901 West 22nd Street
Oak Brook, Illinois 60521

Dear Mr. Slaughter:

Your letter dated December 6, 1972, to Mr. Harold White of our Chicago Office was forwarded to this Office for comment.

The tank erection ladders, which are attached to steal plate construction of various sized tanks as they are constructed and removed from the structure at completion of job, are classified as being a portable metal ladder.

Portable metal ladders provided by the employer shall be in accordance with the provisions of the American National Standards Institute, (ANSI) A14.2-1956 safety code for the portable metal ladders.

I hope this information will be useful to you, and if I can be of any additional assistance, please do not hesitate to let me know.

Sincerely yours,

Allen E. Martin, Chief Construction Standards