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.

November 15, 2002

Mr. Keith Harkins
Safety Manager
Linbeck/Kennedy & Rossi
One Maguire Road
Lexington, Ma 02421

Re: Whether a warning line at 6 feet used to protect roofing workers may also be used to meet fall protection requirements for HVAC construction workers; §1926.502(b)

Dear Mr. Harkins:

This is in response to your letter dated June 10, 2002, to the Occupational Safety and Health Administration (OSHA) requesting clarification on the use of fall protection systems for employees other than roofers, working on low slope roofs. I apologize for the delay in answering your inquiry. We have paraphrased your questions
1 as follows:

Question (1): Scenario: multiple trades - roofers as well as mechanical trades - are working on a low slope roof. Under §1926.501(b)(10), the roofers can comply with fall protection requirements by using a warning line 6 feet from the edge. In accordance with OSHA's August 1, 2000, letter to Mr. Mark Troxell, the mechanical trades, who are installing HVAC equipment, can work without personal fall protection as long as they stay inside a warning line 15 feet from the edge. Since both roofers and mechanical trades are working on the roof at the same time, is it permissible in this situation for the mechanical trades to use the roofers' warning line that is 6 feet from the edge? We would require the mechanical trades to be trained and required to use fall protection if they were to work between the warning line and the edge. Also, the warning line would comply with the criteria requirements in §1926.502(f). Is this acceptable?

As explained below, the answer is no.

OSHA's fall protection standard for construction, 29 CFR Part 1926 Subpart M (beginning at §1926.500), generally requires fall protection when there is a fall distance of 6 feet or more. In a few, very specific situations (low-slope roof work, some leading-edge work, precast concrete erection and residential construction; see §1926.501(b)(2), (12), and (13)), because of feasibility limitations, the standard permits the use of a warning line, in combination with other measures, instead of conventional fall protection (guardrail systems, personal fall arrest systems or safety net systems) to keep employees away from an edge.

Installation of HVAC equipment does not fall within the categories listed; i.e., leading-edge work, precast concrete erection or residential construction. Therefore, the warning line at the 6-foot option does not apply.

As explained in the August 1, 2000, Troxell letter, where certain conditions are met, the use of a warning line 15 feet back from the edge will be considered a de minimis violation of the guardrail criteria in §1926.502(b). The conditions that must be met for the application of this policy are as follows:

  1. A warning line is used 15 feet or more from the edge;
  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 edge; and
  4. The employer effectively implements a work rule prohibiting the employees from going past the warning line.



Therefore, where these conditions are met, you may use a warning line 15 feet back from the edge to protect the HVAC workers.

Applying the policy to your mixed-trades scenario

The fact that the HVAC workers are working on the roof at the same time as the roofing workers does not alter the fact that the standard does not permit the HVAC workers to rely on a warning line at 6 feet from the edge for fall protection. If you believe that use of two warning lines - one at 6 feet and one at 15 feet -- would be confusing or otherwise unworkable, you can protect the HVAC workers with conventional fall protection equipment and dispense with the 15-feet warning line.

If you need further clarification on this subject, please contact us by fax at U.S. Department of Labor, Directorate of Construction, [Office of Construction Standards and Guidance], #202-6931689. You can also contact us by mail at the above office, Room N3468, 200 Constitution Avenue, N. W., Washington, DC 20210, although due to continuing anthrax decontamination procedures there will be a delay in our receiving correspondence.


Russell B. Swanson
Directorate of Construction




1In your second question, you ask, what fall protection options the employer has for protecting a maintenance worker who is working more than 6 feet but less than 15 feet from a roof's edge? Because this question involves the application of the general industry standards, rather than the construction standards, we have forwarded it to the [Directorate of Enforcement Programs] for response. [back to text]

[Corrected 7/29/03]