High-Visibility Vests and Clothing: Classes, Standards, and When They Are Required

High-visibility clothing is one of the most effective and affordable forms of PPE for preventing struck-by accidents. In the UAE, where construction activity occurs around the clock and many worksites operate adjacent to active roadways, hi-vis vests and clothing are legally mandated for all personnel in designated work zones.

Visibility Classes Explained

The EN ISO 20471 standard defines three classes of high-visibility clothing based on the minimum area of fluorescent and retroreflective material. Class 1 provides the minimum level of visibility and is suitable for low-risk environments with slow-moving traffic. Class 2 vests offer greater visibility for moderate-risk areas. Class 3 garments — which include full jackets or coveralls — provide the highest level of conspicuity and are required for workers near high-speed traffic or in complex construction zones.

Fluorescent vs Retroreflective Materials

Fluorescent material makes the wearer visible during daylight by converting UV light into visible light. The most effective colours are yellow-green and orange-red. Retroreflective tape returns light back to its source — such as vehicle headlights — making the wearer visible at night. Effective hi-vis garments combine both materials to ensure 24-hour visibility.

Hi-Vis in UAE Summer Conditions

UAE workers face the challenge of wearing hi-vis clothing in extreme heat. Modern hi-vis vests are available in breathable mesh fabrics that allow airflow while maintaining the required fluorescent area. Lightweight, moisture-wicking polyester vests with mesh panels are recommended for outdoor construction workers during summer months.