When you encounter warning lines it is important to remember that these are meant to warn employees and the public alike from hazards, particularly falls from elevated surfaces.
The purpose of warning lines is simply to alert everyone that a fall hazard is present. In addition to roofs, warning lines can also be found on roadways and work sites. Ignoring them can result in injury or even death.
Wherever you encounter these visual reminders always recognize that the lines are there for your safety and act accordingly.
OSHA: Visual Identification
OSHA mandates that warning lines be present on elevated surfaces including roofs that will be accessed by employees, contractors, and the public in order to serve as a visual identification of working zones, leading edges and openings.
The warning line serves to alert you to potential dangers beyond the barriers. Additional fall protection equipment is required by OSHA to keep workers safe near leading edges and openings. These may include harnesses, safety rails, nets or other fall protection systems.
For the public, warning lines should suffice to keep them from straying into an area they aren’t authorized to enter. When it comes to construction safety. It’s not always about employee safety.
The term warning line is a misnomer since a simple yellow line spray painted on the surface would not be sufficient to meet OSHA guidelines.
A warning line must include ropes, wires, or chains attached to free standing stanchions. Yellow safety flags must be present on the lines linking the stanchions at intervals of six feet or less.
Additionally, the stanchions must be able to withstand a tensile force of up to five hundred pounds.
Warning lines must be set up at the correct distance from the roof edge or opening in order to perform its intended function.
According to OSHA regulations, a warning line must be set up six feet from the edge and 15 feet from the edge if any mechanical equipment is in use. If these distances are not observed the area can’t be considered to be in compliance with federal guidelines. When you need to work closer to a leading edge then allowed by warning lines consider other forms of fall protection such as guardrails, anchors or horizontal lifelines.
The two most common types of warning lines are portable and permanent.
Portable Warning Lines
Portable warning lines are lighter weight and are more easily torn down. This allows them to be moved as needed, which gives these warning lines an advantage in flexibility over permanent lines.
These types of warning lines are best utilized to designate temporary work areas rather than being used as a more permanent reminder of the potential for injury or even death from a fall.
Permanent Warning Lines
Permanent warning lines aren’t actually fixed to the elevated surface either but the heavier stanchions and bases make them less convenient to move than portable units.
Meant to serve as a more durable visual reminder of leading edges and openings, these systems are typically left on roofs that are accessible to the public as well as workers.
Both portable and permanent warning lines come in a safety yellow finish, per OSHA regulations, to enhance visibility.
Warning Lines Alert “Everyone”
Warning lines are designed to protect everyone from falls and other hazards within a designated work area by providing a warning that a hazard is present, not just workers.
Everyone from mall patrons to motorists will encounter warning lines at some point. These systems only work when they are utilized properly and when workers and the public recognize that warning lines must be heeded at all times.
By Peter Kavia
CAI Safety Systems
Peter has been a safety expert for almost 20 years and is certified as a Qualified Fall Protection expert. He currently holds the title of Director of Operations for CAI Safety Systems, a custom turnkey fall protection company in Southern California.