Federal requirements for the anchorages and connectors in personal fall arrest systems.

February 8, 2011

Paul F. Laubenthal, P.E.
SSOE, Inc.
Architects and Engineers
1001 Madison Avenue
Toledo, OH 43604

Re: Federal Requirements for the anchorages and connectors in personal fall arrest systems used for construction.

Dear Mr. Laubenthal:

This letter addresses your inquiry dated September 25, 2009 to the Occupational Safety and Health Administration (OSHA). In your inquiry, you asked questions regarding evaluation and design requirements of the anchorages used for attaching personal fall arrest system in construction. This letter constitutes OSHA's interpretation only of the requirements discussed and may not be applicable to any question not detailed within your original correspondence.

We have paraphrased your questions as follows:

Question (1): Whether the evaluation or design of anchorages used for attaching personal fall arrest system equipment is based on the yield strength or the ultimate strength of the supporting member?

Answer:

29 CFR §1926.502(d) (15) provides:

• Anchorages used for attachment of personal fall arrest equipment shall be independent of any anchorage being used to support or suspend platforms and capable of supporting at least 5,000 pounds (22.2 kN) per employee attached, or shall be designed, installed, and used as follows:
• (i) as part of a complete personal fall arrest system which maintains a safety factor of at least two; and
• (ii) under the supervision of a qualified person.

29 CFR §1926.502(d)(15) requires the anchorages to support 5,000 pounds per employee or as an alternative (d)(15)(i) requires maintaining a factor of safety of at least two to the maximum fall arresting force of the personal fall arrest system. Maximum fiber stresses, based on either a 5,000 pound load per employee attached or two times the maximum fall arresting force of the system, are limited by the yield strength of the supporting member (when permanent deformation first begins).

Question (2): For dee-rings and snaphooks, are the 5,000 pound tensile strength requirement and 3,600 pound minimum tensile load requirement based on the ultimate and yield strengths of the material, respectively?

Answer:

29 CFR §1926.502(d) provides:

• (3) Dee-rings and snaphooks shall have a minimum tensile strength of 5,000 pounds (22.2 KN).
• (4) Dee-rings and snaphooks shall be proof-tested to a minimum tensile load of 3,600 pounds (16 KN) without cracking, breaking, or taking permanent deformation.

For dee-rings and snaphooks, the 29 CFR §1926.502(d)(3) requirement of a minimum tensile strength of 5,000 pound is based upon yield strength of the material. This requirement is based on use without proof-testing and without certification by a qualified person. However, the 29 CFR § 1926.502(d)(4) requirement for a minimum tensile load of 3,600 pounds is for proof-testing prior to use. The device fails this proof-test if it cracks, breaks or begins to take permanent deformation under a 3,600 pound or a lighter load.

If you have any questions about this response, or need further clarification on this subject, please contact us by fax at (202) 693-1689. You may also contact us by mail at the U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Guidance, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210.

Sincerely,

James G. Maddux, Director
Directorate of Construction