Conventionally, in order to achieve the status of a CE marked product high-visibility items must have all of their component materials tested, usually in line with a harmonised standard. They must be subjected to both design and ergonomic assessments, and they must have a technical file compiled that shows details of their manufacture, materials, design and specific attributes.

All high-visibility products incorporate materials that are retro-reflective, that is materials that are very effective at returning directional light that strikes their surface back towards its point of origin. They create a cone of retro-reflected light; hence an observer within that cone will see a wearer of the materials. These materials are primarily intended to enhance a person’s visibility in the dark, when they are illuminated by vehicle headlights.

High-visibility garments also incorporate background materials, fluorescent fabrics that enhance a wearer’s visibility in daylight. These are fabrics that are coloured with fluorescent dyes.

There are three harmonised standards that are used to assess visibility articles, two are for garments and the third is for high visibility accessories