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.


Note: The minimum load requirements published in the proposed revisions to 1910.66 were re-codified in the final rule to Appendix C Section I. - Mandatory at paragraph (c)(3) and (5). Anchorage requirements are included in Section I. at paragraph (c)(10) of the final rule.


December 9, 1986

Paul A. DeMillo, AIA
RTKL Associates, Inc.
400 East Pratt Street
Baltimore, Maryland 21202

Dear Mr. DeMillo:

This is in response to your letter of October 27, 1986, concerning attachment requirements for window washing equipment as required by the Occupational Safety and Health Administration (OSHA) and further confirms your conversation with Joseph Bode.

Building roof anchorages intended for the support of window washing devices and various suspension systems shall be a permanent part of the structure and shall be sound, rigid, and capable of supporting the maximum intended loading without displacement or deformation. (Reference 29 CFR 1910.28(a)(2) and 1910.28(a)(26).)

Completely separate anchorages shall be provided to attach worker safety lines (lifelines), which will safely suspend the worker in case of a fall. (Reference 29 CFR 1910.28(g)(9) and 1910.28(g)(4).) Additionally, the American National Standards Institute, Inc., (ANSI) has specified in ANSI A10.14, Requirements for Safety Belts, Harnesses, Lanyards, Lifelines, and Drop Lines for Construction and Industrial Use that such anchorages must be capable of supporting a minimum dead weight load of 8,400 pounds. (Reference ANSI A10.14-1975, Section 2.5.)

Currently, proposed revisions to the OSHA standards at 29 CFR 1910.66 intend to require as a minimum that lifeline anchorages provide for supporting the potential impact load of an employee's fall. However, lanyards and vertical lifelines shall be capable of sustaining a minimum load of 5,000 pounds. (Reference CFR Vol. 50, No. 14, January 22, 1985, page 2935, Appendix D, paragraph 1(c)(3) and (7).)

Roof anchorages provided to support portable suspension equipment such as boatswains chairs, single-point suspension scaffolds and two-point suspension scaffolds, shall provide for support, without deformation or failure, of at least four (4) times the maximum intended load and shall be independent of anchorages provided for fall protection systems. (Reference 29 CFR 1910.28(a)(4), 1910.28(g)(9), and 1910.28(j)(4).)

It is, therefore, logical to assume that the minimum design dead weight load to be expected at roof anchorages will be 5,000 pounds. In any event, conscientious building owners will identify each roof anchorage and the loading it is capable of withstanding. Under 29 CFR 1910.145(c)(3), safety signs shall be used where there is a need for general instructions and suggestions relative to safety measures. The safety sign standard is applicable to the identification of anchorages.

Pertinent portions of referenced standards are enclosed for your convenience. If we may be of further assistance, please contact us.


John B. Miles, Jr., Director
Directorate of Field Operations

[Corrected 12/01/2009]