ISO 20471

ISO 20471 is an international standard specifying requirements for high-visibility clothing capable of visually signaling the user's presence. It defines performance requirements for color and retroreflection, as well as minimum areas for background and retroreflective materials used in the design of high-visibility clothing. The standard is applicable to high-risk situations and covers garments such as vests, jackets, trousers, and coveralls.

The primary purpose of ISO 20471 is to provide a means for ensuring that workers in hazardous environments, such as construction sites, road works, or emergency services, are highly visible to approaching vehicles and equipment operators, particularly in low light conditions or adverse weather.

The standard classifies garments into three classes (Class 1, Class 2, and Class 3) based on the minimum areas of visible materials (both background and retroreflective) that the garment must incorporate. Class 3 offers the highest level of visibility, while Class 1 offers the lowest. The higher the class, the greater the visibility and therefore the greater the protection afforded to the wearer.

Compliance with ISO 20471 requires garments to be tested and certified by a notified body. The certification mark indicates that the garment meets the standard's requirements for color, retroreflection, and area of visible materials. Garments must also be marked with the standard number (ISO 20471) and the class number.

The standard specifies requirements for the color of the background material (typically fluorescent yellow, orange, or red) and the retroreflective material (typically silver or white). The color must meet specific chromaticity and luminance factor requirements as defined in the standard. The retroreflective material must meet specific retroreflection performance requirements to ensure visibility at night.

ISO 20471 is regularly updated to reflect advancements in materials and technology. Users should always refer to the latest edition of the standard to ensure compliance with current requirements.