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.

January 3, 2005

Mr. Dan Steigerwald
Safety Consultant
IMA Community Business
250 N. Water Street
600 IMA Plaza
Witchita, KS 67202

Re: Use of a warning line instead of conventional fall protection; Part 1926 Subpart M.

Dear Mr. Steigerwald:

This is in response to your October 19, 2004, letter to the Occupational Safety and Health Administration (OSHA). You ask for information regarding the application of the fall protection standard, Subpart M, with respect to non-roofing work performed while on a roof. Specifically, you ask for an explanation of OSHA's policy of allowing an employer to protect its employees by implementing a warning line system 15 feet from an unprotected side, edge, or hole during the performance of non-roofing activities.

We have paraphrased your question as follows:

Question: My employees are engaged in mechanical work on roofs. For workers engaged in roofing work, §1926.501(b)(10) permits an employer to use a warning line 6 feet back from the edge in combination with a monitor. In a November 15, 2002, letter of interpretation to Mr. Keith Harkins, OSHA stated that a warning line system set 15 feet from an unprotected edge is permitted to be used instead of conventional fall protection to protect employees engaged in non-roofing activities.

Why is it okay to use a warning line with a 6 foot set-back to protect roofers but not okay to use a 6-foot set-back to protect non-roofers? Why does the policy described in the Harkins letter for non-roofers have a set-back of 15 feet rather than 6 feet?

Answer: Under §1926.501(b)(1), employees generally must be protected from the fall hazards posed by unprotected sides and edges by the use of conventional fall protection:

(b)(1) Unprotected sides and edges. Each employee on a walking/working surface (horizontal and vertical surface) with an unprotected side or edge which is 6 feet or more above a lower level shall be protected from falling by the use of guardrail systems, safety net systems, or personal fall arrest systems.

As discussed in the Preamble to Part 1926 Subpart M (Volume 59 of the Federal Register, page 40683), OSHA determined in the rulemaking that there is no safe distance from an unprotected side or edge of a walking/working surface that would render protection unnecessary. However, in the rulemaking for Subpart M, OSHA determined that in certain very limited situations, warning lines are an appropriate means of protection. Section 1926.501(b)(10) sets out the fall protection requirement for roofing work on low slope roofs. Under that section an employer may use a combination of warning lines 6 feet (and in some cases 10 feet) back from the edge in combination with monitors in place of personal fall protection equipment or guardrails. Under §1926.501(b)(2), employers engaged in other specified work, such as leading edge work, precast concrete erection work and residential construction, may develop and implement a site-specific fall protection plan that uses alternative fall protection methods if they can demonstrate the infeasibility of conventional fall protection. As can be seen in the examples given in Appendix E to Subpart M, warning lines 6 feet back from the edge can be used as part of such a plan.

Therefore, the Agency identified in the rulemaking the specific situations where warning lines 6 and 10 feet back from a hole or edge were appropriate substitutes for guardrails, personal fall protection, nets and covers. It would be inappropriate for us to revisit those determinations outside of the rulemaking process and allow warning lines to be used in other circumstances at 6 and 10 feet back. Consequently, it would be inappropriate to apply a de minimis policy1 that would have the effect of extending the provisions for warning lines at 6 and 10 feet to situations other than the limited ones identified in the standard.

In contrast, a question remained about whether a de minimis policy on the use of warning lines in areas further back from those specifically addressed in the rule would be appropriate. In our letter of interpretation to Barry Cole, dated May 12, 2000, we stated:

We have now had five years of experience with the application of the rule since it was published in 1994. We continue to believe that distance alone is ineffective to protect workers from unprotected sides or edges. However, we have determined that, in the area further back from the distances specified for the warning lines permitted under the standard, there is a point that is sufficiently far from the edge or hole to warrant the application of a de minimis policy regarding non-conforming guardrails.

At 15 feet from the edge or hole (in the case of a hole, measured from the nearest edge of the hole), a warning line, combined with effective work rules, can be expected to prevent workers from going past the line and approaching the edge. Also, at that distance, the failure of a barrier to restrain a worker from unintentionally crossing it would not place the worker in immediate risk of falling off the edge. Therefore, we will apply a de minimis policy for non-conforming guardrails 15 or more feet from the edge under certain circumstances.

We concluded that the use of certain physical barriers that fail to meet the criteria for a guardrail would be considered a de minimis violation of the guardrail criteria in §1926.502(b) where all of the following are met:

  1. A warning line is used 15 feet or more from the edge (or nearest edge of a hole);
  2. The warning line meets or exceeds the requirements in §1926.502(f)(2);
  3. No work or work-related activity is to take place in the area between the warning line and the hole or edge; and
  4. The employer effectively implements a work rule prohibiting the employees from going past the warning line.

If you need any 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 Under OSHA's de minimis policy, de minimis violations are those that have no direct or immediate relationship to safety or health. Consequently, no citation is issued. [back to text]