Sioen PRO guide on combining EN ISO 20471 high-vis products

Why combining matters in high visibility protection

In many work environments, wearing high-visibility clothing is not optional — it is essential. But visibility requirements vary: sometimes a single garment suffices, in other situations a higher level of visibility is required. EN ISO 20471 makes it possible to reach the required class not only with one garment, but also by combining different certified garments.

This flexibility allows you to adapt to weather conditions, comfort needs, and specific tasks, without compromising safety.

3 Safety classes How combining EN ISO 20471 garments works

3 Safety classes

The purpose of EN ISO 20471 certified clothing, is to make the wearer more visible in situations and work environments where it is vital to be seen, in order to help prevent accidents.

Each separate high-visibility garment is accorded a certain safety class, based on the amount of fluorescent fabric and reflective stripes used in the garment. The more fluorescent and retroreflective material present in the garment, the higher the class. Choose your class of high-visibility workwear in accordance with your specific work situation and the risks you are exposed to.

	Fluorescent material	Retroreflective material
Class 1	at least 0.14 m²	at least 0.10 m²
Class 2	at least 0.50 m²	at least 0.13 m²
Class 3	at least 0.80 m²	at least 0.20 m²

How combining garments works

You don’t always need a single class-3 jacket to satisfy a Class 3 requirement — under certain conditions, two or more EN ISO 20471 certified garments can be combined to achieve a higher class together. This means that when worn together, they achieve a higher visibility class than when worn alone.

Consult the table below to find out which combination of products will give you a higher class when worn together. Make sure to always check which safety class is required for your specific work situation and make sure your combination is approved by your notified body.