The Crit'Air sticker (certificat qualité de l'air) is a secure round sticker that must be affixed to a vehicle's windscreen.

It indicates the vehicle's environmental class.

There are six classes, from Crit'Air 0 (the cleanest, for 100% electric and hydrogen vehicles) to Crit'Air 5 (the most polluting).

Some older vehicles are so polluting they are not eligible for any sticker ('non classés').

The class is determined based on three criteria: 1.

**Vehicle Type:** Car, light commercial vehicle, truck, motorcycle, etc.

2.

**Motorization:** Electric, petrol, diesel, etc.

3.

**Euro Standard:** The European emissions standard the vehicle meets, which is indicated on its registration document (carte grise).

This sticker is mandatory to drive in Low-Emission Zones (ZFE-m) and can also be required during pollution peaks when emergency traffic restrictions are implemented.

The sticker allows authorities to easily identify which vehicles are authorized to circulate and which are not.

It is a key tool in France's air quality management policy.