One common question people ask about work on low slope roofs concerns warning line use. Specifically, clients ask: “Are rooftop warning lines OSHA compliant?”

Close-up of warning line marker
The short answer to this seemingly simple question is “it depends.”
Here are the factors you need to assess…
For work scenarios less than six feet from the roof edge, per OSHA 1910.28(b)(13)(i), employers must protect workers from falling with a guardrail system, safety net system, travel restraint system, or personal fall arrest system.
Put another way, warning lines are not an OSHA compliant form of fall protection under these circumstances.
Per OSHA 1910.28(b)(13)(ii), when work is performed at least six feet but less than fifteen feet from the leading edge, employers may protect employees from fall hazards with a passive restraint guardrail system, safety net, travel restraints system, or a personal fall arrest system.