29 CFR 1926 · Construction · Subpart M

1926.502(f): Warning Line Systems

By Black Belt Safety Editorial Team Official text as of October 15, 2026 Data updated November 7, 2026 5 min read

Low-slope roof warning line set back 6 feet from the edge, 10 feet where equipment travels
Warning lines on low-slope roofs. Not to scale; the official text controls.
In plain words:

Warning lines on roofs must surround the work area at least 6 feet from the edge (10 feet from edges perpendicular to the direction mechanical equipment moves), be flagged every 6 feet, hang 34 to 39 inches high and be strong enough to resist the required loads. Mechanical equipment may only be used or stored in protected areas.

Key takeaways

  • 1926.502(f) is part of OSHA's construction standards (29 CFR Part 1926, Subpart M).
  • OSHA cited it 206 times in the last 3 years, in 138 inspections, with $305,065 in current penalties.
  • Most citations: MI (39), PA (33), MD (19).
  • Related part: 1926.502(f)(1) (150 citations).
  • Free 5-minute toolbox talk for your crew below.

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206citations, 3 years
$305,065current penalties
138inspections
0linked injury cases
In this article
  1. What this rule covers
  2. Official text
  3. Where and how often it was cited
  4. Free toolbox talk
  5. OSHA interpretation letters
  6. Related parts of this rule
  7. Get your crew competent
  8. About this page

What this rule covers

29 CFR 1926.502(f) ("Warning line systems") is one requirement inside 1926.502 Fall protection systems criteria and practices, an OSHA construction standard (Part 1926, Subpart M). It includes 13 sub-paragraphs. The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.

Official text

(f) Warning line systems. Warning line systems [See § 1926.501(b)(10)] and their use shall comply with the following provisions: 206 citations

(1) The warning line shall be erected around all sides of the roof work area. Open (f)(1) 150 citations

(i) When mechanical equipment is not being used, the warning line shall be erected not less than 6 feet (1.8 m) from the roof edge. Open (f)(1)(i) 47 citations

(ii) When mechanical equipment is being used, the warning line shall be erected not less than 6 feet (1.8 m) from the roof edge which is parallel to the direction of mechanical equipment operation, and not less than 10 feet (3.1 m) from the roof edge which is perpendicular to the direction of mechanical equipment operation. 5 citations

(iii) Points of access, materials handling areas, storage areas, and hoisting areas shall be connected to the work area by an access path formed by two warning lines. Open (f)(1)(iii) 45 citations

(iv) When the path to a point of access is not in use, a rope, wire, chain, or other barricade, equivalent in strength and height to the warning line, shall be placed across the path at the point where the path intersects the warning line erected around the work area, or the path shall be offset such that a person cannot walk directly into the work area. 3 citations

(2) Warning lines shall consist of ropes, wires, or chains, and supporting stanchions erected as follows: Open (f)(2) 51 citations

(i) The rope, wire, or chain shall be flagged at not more than 6-foot (1.8 m) intervals with high-visibility material; Open (f)(2)(i) 13 citations

(ii) The rope, wire, or chain shall be rigged and supported in such a way that its lowest point (including sag) is no less than 34 inches (.9 m) from the walking/working surface and its highest point is no more than 39 inches (1.0 m) from the walking/working surface; Open (f)(2)(ii) 31 citations

(iii) After being erected, with the rope, wire, or chain attached, stanchions shall be capable of resisting, without tipping over, a force of at least 16 pounds (71 N) applied horizontally against the stanchion, 30 inches (.8 m) above the walking/working surface, perpendicular to the warning line, and in the direction of the floor, roof, or platform edge;

(iv) The rope, wire, or chain shall have a minimum tensile strength of 500 pounds (2.22 kN), and after being attached to the stanchions, shall be capable of supporting, without breaking, the loads applied to the stanchions as prescribed in paragraph (f)(2)(iii) of this section; and Open (f)(2)(iv) 2 citations

(v) The line shall be attached at each stanchion in such a way that pulling on one section of the line between stanchions will not result in slack being taken up in adjacent sections before the stanchion tips over. 1 citations

(3) No employee shall be allowed in the area between a roof edge and a warning line unless the employee is performing roofing work in that area. 5 citations

(4) Mechanical equipment on roofs shall be used or stored only in areas where employees are protected by a warning line system, guardrail system, or personal fall arrest system. Open (f)(4)

Source: eCFR, text current as of 2026-10-15. Read all of 1926.502.

See every company cited for this rule.

Export the list: 138 inspections cited 1926.502(f) in the last 3 years, with employer, location, penalty and date.

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Where and how often it was cited

YearCitations
20234
202484
202561
202657

Top states: MI (39), PA (33), MD (19), IL (16), WI (12)

Largest penalties

EmployerLocationPenalty for this rule
CPX2026XJW184X0213 - DICKENS QUALITY DEMOLITION, L.L.C.PHOENIX, AZ$21,282
INVALEON TECHNOLOGIES CORPORATIONSOUTHWICK, MA$11,292
JOHNNY'S GENERAL CONSTRUCTIONEL PASO, TX$9,404
FOR SURE ROOFING, LLCANKENY, IA$9,268
PRO COM ROOFING CORPORATION.WILLOW GROVE, PA$9,104

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OSHA interpretation letters

None exist. OSHA has not published a letter of interpretation for 1926.502(f).

Related parts of this rule

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About this page

Sources

3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.

Written and reviewed by

Black Belt Safety Editorial Team

Site Safety Officer and Safety Professional

OSHA 30 · CPR · USACE CQM

Written and reviewed by the Black Belt Safety team. Every post is checked against the OSHA standard or agency source it cites.

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