NFPA 170: The Standard Fire Safety Symbols for Evacuation Plans

NFPA 170, the Standard for Fire Safety and Emergency Symbols, is a slim but powerful NFPA document that does one job extraordinarily well: it defines a consistent vocabulary of symbols for use on architectural drawings, fire protection shop drawings, posted evacuation maps, pre-incident plans and emergency operations diagrams. Before NFPA 170 was widely adopted, different architects, fire protection engineers and fire departments used different glyphs for the same equipment, which made it possible for a fire crew arriving at a building to misread a posted plan or a sprinkler riser diagram in the critical first minutes of an incident. By giving every safety device a single recognizable shape, NFPA 170 makes evacuation diagrams readable by any fire fighter, building occupant or AHJ in the country. The standard is referenced in NFPA 101, NFPA 1, NFPA 1620 (pre-incident planning) and many local fire prevention codes, and it is the foundation of the icon library used in every credible evacuation-plan tool, including EvacPlan Generator.

NFPA 170 organises symbols into six chapters that map roughly to the responsibilities of different audiences. Chapter 4 covers architectural and fire-protection symbols used on construction drawings — wall types, fire ratings, door swing direction, smoke barriers, fire walls, fire dampers. Chapter 5 covers fire suppression symbols — sprinkler heads (pendent, upright, sidewall, ESFR), standpipes, hose reels, dry chemical systems, clean agent systems, water mist. Chapter 6 covers fire detection and alarm symbols — smoke detectors, heat detectors, manual pull stations, audible/visible appliances, control panels. Chapter 7 covers symbols for evacuation maps — exits, you-are-here markers, primary and secondary routes, assembly points, areas of refuge. Chapter 8 covers symbols for pre-incident planning — used by fire departments to map utility shut-offs, hazardous material locations, fire lanes and command post positions. Chapter 9 covers emergency operations and incident-command map symbols. Most posted evacuation plans pull primarily from Chapters 5, 6 and 7.

NFPA 170 standardises not only the shape of each symbol but also color, size and labeling. For posted evacuation maps the safety green color (per ISO 3864 and NFPA 170 Section 7.6) is reserved for safe condition information — exits, exit routes, assembly points and first-aid stations. Red is reserved for fire protection equipment — extinguishers, alarms, sprinklers, hose connections. Yellow indicates caution or hazard, and blue indicates mandatory action. Symbol size on posted evacuation plans should make every element clearly visible from the typical reading distance (about 6 ft for posted maps in corridors and lobbies); the standard recommends symbols be no smaller than 1/4 inch when printed at the final posted size. Labeling is required when a symbol could be ambiguous — for example, a generic fire alarm bell symbol may be labeled F.A. or a waterflow alarm specifically labeled WF. The Map Key on the posted plan must list every symbol used and its meaning in plain English so a building occupant without code training can decode the diagram.

A code-compliant posted evacuation plan typically uses the following NFPA 170 symbols: portable fire extinguisher (a red circle or labeled rectangle with the extinguisher icon and class designation), manual fire alarm pull station (the F-in-a-square symbol of NFPA 170 Chapter 6), notification appliance horn/strobe (commonly a wedge for horn and a starburst for strobe), exit (a stylized doorway with arrow), exit door (a labeled rectangle at the doorway), area of refuge (a wheelchair-with-shelter glyph), assembly point (a circle of people), sprinkler control valve (an open valve handle), fire department connection (an F.D.C. labeled siamese symbol), AED (a heart with a lightning bolt), first-aid station (a cross or first-aid kit), and the all-important YOU ARE HERE marker (a high-contrast star, dot or arrow keyed to the current location). Routes are drawn as solid green lines for primary egress and dashed green for secondary egress, with arrowheads indicating the direction of travel toward the nearest exit.

NFPA 170 covers symbols on plans and drawings, while ISO 7010 covers the safety signs posted in the physical environment — the signs on walls, doors and ceilings. The two are designed to be complementary: an evacuation plan drawn with NFPA 170 symbols guides an occupant to an exit door labeled with an ISO 7010 green running-man sign. Whenever possible, choose NFPA 170 symbols that visually resemble the corresponding ISO 7010 sign so the occupant sees the same vocabulary on the plan and on the wall. For example, the green running-man-with-arrow ISO 7010 sign should pair with the same green arrow icon on the posted plan; the red flame ISO 7010 fire-alarm sign should pair with the red NFPA 170 manual pull station symbol. A building that uses ISO 7010 signage in its corridors but NFPA 170 only in its plans is still compliant — but using consistent visual cues between the wall and the plan reduces decision time during the chaotic first seconds of an evacuation.

NFPA 170 is on a regular three-year revision cycle, with the most recent editions published in 2018, 2021 and 2024. Most authorities having jurisdiction adopt either the edition referenced in their adopted version of NFPA 101 (typically two cycles behind, so most jurisdictions in 2026 are working from the 2021 NFPA 170) or a specific edition cited in their local fire prevention code. Always confirm with the AHJ which edition applies. Updates between editions are usually evolutionary rather than revolutionary — new symbols added for emerging technologies (clean-agent systems, smoke control fans, electronic access controls), color and labeling clarifications, and small artwork refinements. A posted evacuation plan drawn to the 2018 edition is generally accepted under the 2021 and 2024 editions because the older symbols remain recognisable. However, any plan being prepared today should follow the most current adopted edition; legacy symbols that have been superseded should be replaced at the next plan revision.

The simplest way to ensure NFPA 170 compliance is to use a plan-creation tool whose icon library is already aligned with the standard. EvacPlan Generator (www.evacplangenerator.com), developed by PlotStuff (www.plotstuff.com), ships with an NFPA 170-aligned icon set covering portable fire extinguishers by class, manual pull stations, notification appliances, sprinkler control valves, fire department connections, AEDs, first-aid stations, areas of refuge, exits and assembly points. Each icon is labeled in plain English and drawn in the correct color, and the auto-generated MAP KEY on every exported PDF lists only the icons actually used on that plan, so the legend stays clean. The same icon set is used across every page of a multi-page project so the building owner ends up with a visually consistent set of plans across every floor of the building. Using a standardised library is the difference between a plan an AHJ approves on the first review and one that requires multiple revisions to align symbols with NFPA 170.