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.

April 5, 2005

James R. Rhudy
One CB&I Plaza
2103 Research Forest Drive
The Woodlands, TX 77380-2624

Re: Fall protection requirements for workers constructing a water tower while on a scaffold.

Dear Mr. Rhudy:

This is in response to your letter dated January 11, 2005, to the Occupational Safety and Health Administration (OSHA). You ask for a clarification of the fall protection requirements for workers constructing a water tower while on a scaffold.

We have paraphrased your question as follows:

Question: Scenario: We are constructing a "500 MG" water tower (see illustration of "Waterspheroid" below). As can be seen in the illustration below, workers use a scaffold that is attached to the interior side of the tank. The total width of the scaffold is approximately 40 inches. The fall distance from the platform to both the interior and exterior is more than 10 feet. What are the requirements for fall protection in this situation?

Depiction of CB&I Water -- 500 mg waterspheroid layout with scaffold attached to interior side of tank; illustration shows scaffold location and dimensions

Answer: Title 29 CFR 1926.451(g)(1) introductory text and 1926.451(g)(vii) state:

(g) Fall protection. (1) Each employee on a scaffold more than 10 feet (3.1 m) above a lower level shall be protected from falling to that lower level. Paragraphs (g)(1)(i) through (vii) of this section establish the types of fall protection to be provided to the employees on each type of scaffold.
* * * * *
(vii) For all scaffolds not otherwise specified in paragraphs (g)(1)(i) through (g)(1)(vi) of this section, each employee shall be protected by the use of personal fall arrest systems or guardrail systems meeting the requirements of paragraph (g)(4) of this section.
* * * * *

The fall protection requirements for the scaffold in question are set out in the "catch-all provision" of §1926.451(g)(1)(vii). The employer in the situation you describe has the choice of using either a fall arrest system or a guardrail system to protect employees from fall hazards associated with working from a scaffold more than 10 feet above a lower level.

However, note that §1926.451(g)(4) introductory text and 1926.451(g)(4)(i) state:

(4) Guardrail systems installed to meet the requirements of this section shall comply with the following provisions (guardrail systems built in accordance with Appendix A to this subpart will be deemed to meet the requirements of paragraphs (g)(4)(vii), (viii), and (ix) of this section):
(i) Guardrail systems shall be installed along all open sides and ends of platforms. Guardrail systems shall be installed before the scaffold is released for use by employees other than the erection/dismantling crews. [Emphasis added.]

You have indicated that installation of "guardrails on all open sides" would preclude workers from constructing the waterspheroid wall (to the left of the scaffold in the illustration). Therefore, in the situation you describe, to meet the requirements of §1926.451(g)(1)(vii), you would be required to protect the workers with a fall arrest system.

If you need additional information, please contact us by fax at: U.S. Department of Labor, OSHA, Directorate of Construction, Office of Construction Standards and Guidance, fax # 202-693-1689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N.W., Washington, D.C. 20210, although there will be a delay in our receiving correspondence by mail.


Russell B. Swanson, Director
Directorate of Construction