What photometric characteristics must be considered in high visibility clothing?

Companies need to keep workers safe, especially in high-risk jobs.

One of the ways to promote safety and protection in some workplaces is by using well-fitting work clothing, as this equipment can reduce the risk of accidents and injuries.

This workwear is designed to provide visibility where the risk of not being seen is high. Therefore, workers in industry, construction, road agencies and road and rail operators use this type of overalls. Furthermore, to name a few examples, cyclists, pedestrians on the road, or people in emergency situations on the road, all use this clothing with the aim of visually indicating the presence of these users.

Efficiency is defined by the photometric properties of materials, as well as their minimum area and layout (or design) requirements. High-visibility clothing needs to attract immediate visual attention, that is, it needs to have conspicuous attributes. The brightness, the contrast of colors, the design of the garment and its configuration determine the visual ability to attract attention.

High Visibility Clothing Requirements

Among the requirements for high-visibility clothing in accordance with standard UNE EN ISO 20471, there are requirements concerning background materials, fluorescent materials and combined materials. On the other hand, the standard also specifies the photometric performance requirements of retroreflective materials and composite materials after physical exposure.

Regarding requirements for background materials, non-fluorescent materials and composite materials, the standard specifies a series of requirements. These requirements refer to:

• Color performance of new materials, color after xenon lamp test. In addition, the standard defines a range of values for chromaticity coordinates and lightness factors.

• After testing the color fastness of the substrate and non-fluorescent materials of each layer. Specifically, color fastness to rubbing, color fastness to perspiration, color fastness to washing, color fastness to dry cleaning, color fastness to hypochlorite bleaching and color fastness to hot ironing

• Size change of background material and non-fluorescent material

Mechanical properties of background materials and non-fluorescent materials. More specifically, tensile strength of woven materials, burst strength of knitted materials, tensile and tear strength of coated and laminated fabrics

• Physiological requirements. Specifically, water vapor resistance and heat resistance.

For its part, the standard specifies a series of retroreflective requirements for new materials and retroreflectivity after testing for the photometric performance requirements of retroreflective materials and composite materials after physical exposure.