Hi Vis clothing is essential for keeping workers safe when working near traffic, cranes, forklifts or other vehicles. It is absolutely needed when working at night or in low-light conditions.

The primary role of hi vis is to separate wearers from whatever background environment they are working in, quickly and at a distance and from all angles.

Being such a vital safety element at work, it's important that hi vis garments are somewhat standardised, controlled by legislation and certified as such. The current legislated standard certification is: EN ISO 20471.

The class that a garment falls into can be found on the label of any EN ISO 20471 compliant garment. The label should contain the EN ISO 20471 icon and the relevant class number. The example below shows Class 2:

Which class of hi vis you need for your specific working conditions is beyond the scope of this guide, but the best place to start is with a thorough risk assessment of the working conditions of your employees. the class will depend on the risks the particular worker faces, which will determine the amount of colour and reflective material that needs to be displayed.

The EN ISO 20471 certification determines the amount of both reflective and coloured material and sets the minimum requirements.