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Standard Interpretations - Table of Contents
• Standard Number: 1926.451; 1926.451(a); 1926.451(g); 1926.451(g)(1); 1926.451(g)(2); 1926.451(g)(2)(iii) ; 1926.451(g)(4); 1926.451(g)(4)(ix); 1926.451(g)(4)(v); 1926.451(g)(4)(vii); 1926.451(g)(4)(viii); 1926.451(h); 1926.451(h)(1); 1926.451(h)(2)

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

May 11, 2005

Mr. Douglas A. Holman
1816 River Bend Road
Sevierville, TN 37876

Re: Whether there is a conflict between provisions in §1926.451 regarding the use of screening.

Dear Mr. Holman:

You have submitted nine letters to the Occupational Safety and Health Administration (OSHA) containing a number of questions on the construction scaffold standard (29 CFR Part 1926 Subpart L).
1 We will be responding in a series of separate letters in response; this is the fifth in that series.

We have paraphrased your question regarding the use of screens on scaffolds as follows:

Question: The use of screens on scaffolds is addressed in several places in Subpart L — Scaffolds; specifically, §1926.451(g)(4)(v) and 1926.451(h)(2)(iii) and Non-Mandatory Appendix A each addresses the use of screens. However, their terms appear to be contradictory with respect to the placement of the screening. Which is correct?

Answer: Section 1926.451(g) Fall Protection provides, in part:
(g) Fall protection. 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 ....
* * * * *
(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):
* * * * *
(v) When screens and mesh are used, they shall extend from the top edge of the guardrail system to the scaffold platform, and along the entire opening between the supports .... [Emphasis added.]
Section 1926.451(h) that covers Falling object protection states:
* * *
(h) Falling object protection. (1) In addition to wearing hardhats each employee on a scaffold shall be provided with additional protection from falling hand tools, debris, and other small objects through the installation of toeboards, screens, or guardrail systems, or through the erection of debris nets, catch platforms, or canopy structures that contain or deflect the falling objects.
* * *
(2) Where there is a danger of tools, materials, or equipment falling from a scaffold and striking employees below, the following provisions apply:
* * *
(iii) Where tools, materials, or equipment are piled to a height higher than the top edge of the toeboard, paneling or screening extending from the toeboard or platform to the top of the guardrail shall be erected for a distance sufficient to protect employees below; or [Emphasis added.]
Finally, Non-Mandatory Appendix A to Subpart L of Part 1926 — Scaffold Specifications provides in part:
* * *
This Appendix provides non-mandatory guidelines to assist employers in complying with the requirements of subpart L of this part. An employer may use these guidelines and tables as a starting point for designing scaffold systems. However, the guidelines do not provide all the information necessary to build a complete system, and the employer is still responsible for designing and assembling these components in such a way that the completed system will meet the requirements of §1926.451(a).
* * *
1. General Guidelines and Tables
* * *
(f) Screen installed between toeboards and midrails or toprails shall consist of No. 18 gauge U.S. Standard wire 1-inch mesh. [Emphasis added.]
The two provisions noted above from §1926.451 — paragraphs (g)(4)(v) and (h)(2)(iii) — are requirements in Subpart L while paragraph 1.(f) is in the Non-Mandatory Appendix to the subpart. The paragraphs from the standard, (g)(4)(v) and (h)(2)(iii), address different hazards (fall hazards to workers and falling objects, respectively) and, as such, do not actually conflict with each other in prescribing the use of screens. Nonetheless, it should be noted that the variations in the wording relate to their different purposes.

For example, paragraph 1926.451(g)(4)(v) (the fall protection provision) requires the screen to extend "along the entire opening between the supports ...," whereas paragraph (h)(2)(iii) (the falling object protection provision) only requires it to extend "for a distance sufficient to protect employees below ...." When used for fall protection, it is necessary that the entire area be protected in order to prevent the workers from falling, since the workers necessarily move. In contrast, when used to prevent objects from falling, it is only necessary for the screening to be in place where there are objects that could fall.

With respect to paragraph 1.(f) in the Non-Mandatory Appendix, that paragraph suggests a type of wire mesh that can be used when that use is required or allowed under the standard and, as you noted, also refers to screen installations from toeboards to "toprails or midrails." If a midrail is in place, then the screening would be used for falling object protection rather than fall protection, since the midrail (in conjunction with the top rail) would be the fall protection device. So, in that instance paragraph (g)(4)(v) would not apply to the installation of the screening.

However, we agree that the language in paragraph 1.(f) conflicts with the falling object provision's language in paragraph (h)(2)(iii). Accordingly, we will issue a technical correction to the Appendix to correct this error.

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

1 When we originally received these questions from you in April, 2003, it was unclear to us if you were requesting a response to each or if they were submitted only to call our attention to these issues in the event that OSHA were to do further rulemaking on the standard. We attempted to resolve that with you, but we were unable to obtain a response; consequently, our office closed the file. After your communications with my staff on January 13, 2005, we understand now that you are requesting a response to each question. We apologize for the misunderstanding and resulting delay in providing this response.
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2 The other difference in the two provisions is that the fall protection provision requires the screen to extend down "to the scaffold platform," whereas the falling object provision requires it to extend "to the toeboard or platform." These essentially mean the same thing, because in both cases the entire space between the top guardrail and the platform will be protected.
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3 Note that the language of the standard, 1926.451(h)(2)(iii) is a requirement, whereas the Appendix is non-mandatory. Accordingly, to the extent there is a conflict, the language of 1926.451(h)(2)(iii) takes precedence.
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Standard Interpretations - Table of Contents

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