1926.502(f): Warning Line Systems
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.
Official text: 29 CFR 1926.502(f)
(f) Warning line systems. Warning line systems [See § 1926.501(b)(10)] and their use shall comply with the following provisions:
207 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) 48 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) 52 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) 32 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.
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Where and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 8 |
| 2024 | 84 |
| 2025 | 61 |
| 2026 | 54 |
Top states: MI (39), PA (33), MD (18), IL (16), WI (12)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| CPX2026XJW184X0213 - DICKENS QUALITY DEMOLITION, L.L.C. | PHOENIX, AZ | $21,282 |
| INVALEON TECHNOLOGIES CORPORATION | SOUTHWICK, MA | $11,292 |
| JOHNNY'S GENERAL CONSTRUCTION | EL PASO, TX | $9,404 |
| FOR SURE ROOFING, LLC | ANKENY, IA | $9,268 |
| PRO COM ROOFING CORPORATION. | WILLOW GROVE, PA | $9,104 |
OSHA interpretation letters
- Clarification regarding hazard access zones in steel erection (2014-06-19)
- Fall protection for workers having to walk/work along bridge decks when the edges are finished with a 32 in. high barrier wall. (2013-09-03)
- Acceptable equivalent to control lines for a Controlled Decking Zone (CDZ) in steel erection activities. 29 CFR 1926.760(c)(3). (2010-08-10)
- Use of a warning line instead of conventional fall protection; Part 1926 Subpart M (2005-01-03)
- Fall protection during roofing inspections, investigations, and assessments (2004-03-12)
- Clarification of several residential construction and fall protection issues. (2003-12-17)
- Fall protection requirements for construction workers doing work while on a roof (2003-12-15)
- Compliance of using warning lines and/or control access zones for fall protection on roofs with a slope greater than 4:12. (2003-09-26)
- Fall protection requirements for employees, other than roofers, working on low-slope roofs (2002-11-15)
- Fall protection requirements for both residential and commercial HVAC systems; clarification of confined spaces (2001-09-13)
- Clarification of when mechanical equipment can be used on sloped roofs. (2000-10-17)
- Fall protection non-conforming guardrail criteria for application of a de minimis policy. (2000-05-12)
Related parts of this rule
- 1926.502(f)(1) 150 citations
- 1926.502(f)(2) 52 citations
- 1926.502(f)(1)(i) 48 citations
- 1926.502(f)(1)(iii) 45 citations
- 1926.502(f)(2)(ii) 32 citations
- 1926.502(f)(2)(i) 13 citations
- 1926.502(f)(2)(iv) 2 citations
- 1926.502(f)(4)
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About this page
Official text from the eCFR. Citation and injury numbers from public U.S. Department of Labor enforcement and accident records, copied nightly; 3-year window; data as of 2026-10-18. 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.