Hi-vis class is about area, not brightness

EN ISO 20471 sets three classes, and they are determined by measured area of fluorescent background material and retroreflective tape — not by how vivid the colour appears.

The classes

• Class 1. Lowest area. Typically overtrousers. Suitable only for low-risk, low-speed environments.
• Class 2. Mid area. A standard vest or polo.
• Class 3. Highest area, requiring sleeves. A jacket, or a coverall.

Where people get caught

Class is a property of the garment as worn, and it does not simply add up in the way people assume. A Class 1 trouser worn with a Class 2 vest can achieve Class 3 as an ensemble — but only where the manufacturer has certified the combination. Mixing two makers and claiming Class 3 will not survive an audit.

Washing ends certification

The label states a maximum number of wash cycles. Beyond it the fluorescence has faded and the tape has lost retroreflectivity, and the garment is no longer certified even though it looks acceptable. On a high-speed road that is the difference the standard exists to make.

For anything near moving traffic or plant, specify Class 3 and treat hi-vis as consumable.

Written for Groundwork Workwear — a demonstration store. See the AgenticEcom Suite.