NFPA 1901 Standard For Automotive Fire Apparatus 2016 Edition For Vehicles Less Than 25 feet
The following will provide a quick overview of what you need to ensure your small emergency vehicle’s warning light system complies with NFPA 1901. A small apparatus is defined in NFPA 1901 as a vehicle with a bumperto-bumper length of less than 25 feet, and has the optical center of all optical warning devices at less than 8 feet
Warning Zones
Rev 5/20
Each apparatus, less than 25 feet long, is divided into eight (8) warning zones – four upper and four lower.
Modes of Operation
Calling for Right of Way: Apparatus responding to an emergency.
Blocking Right of Way: Apparatus at emergency scene. White light not permitted.
Permissible Colors
All colors must meet the SAE J578 color
specification for White, Red, Blue, and Amber.
The diagram at right shows which colors are
allowed in each zone.
Color |
Calling for Right of Way |
Blocking Right of Way |
Red |
Any zone |
Any zone |
Blue |
Any zone |
Any zone |
Amber |
Any zone except A |
Any zone |
White |
Any zone except C |
Not permitted |
Flash Rate and Failure
The minimum flash rate allowed is 75 flashes per minute for any single optical source and 150 flashes per minute from all of the light sources visible at any data point (i.e., at least two warning lights are required in each zone). Failure of a lighting device should not leave a data point without a signal.
Light Energy Requirements for Apparatus–Values in Candela-Seconds per Minute