Declaring a retrofitted pollutant emissions treatment device

Principles and objectives

In line with article 3 of the order dated 21 June 2016, vehicles (coaches, buses, and lorries) equipped with retrofitted pollutant emissions treatment devices may receive better Crit'air classifications than vehicles without such devices. *

What retrofitted devices are included ?

Devices that reduce pollutant emissions using particle filters, SCR (Selective Catalytic Reduction) units, or a combination of the two. Particle filters reduce particle emissions, while SCR units limit the emission of nitrogen oxides (NOx). They must be approved and installed after the vehicle is first put on the road.

Which vehicles are included ?

The eligible vehicles are coaches, buses, and lorries ,with compression-ignition engines and cars or vans with compression-ignition engines that have been listed as heavy vehicles due to their pollutant emissions. This includes all diesel heavy vehicles, i.e. those that are covered by European heavy-duty vehicle standards (Euro II, III, IV, etc.).

* However it should be noted that performance only improves in terms of particle/NOx emissions. Other pollutants may be moderately increased. That is why the Euro level listed on the registration remains unchanged.

Steps for receiving a better classification

1. User declaration of a retrofitted device

2. The declaration is assessed by the Air Quality Certificate service

  • The supporting documents and user information are confirmed by e-mail
  • The retrofitted pollutant emissions treatment device is either declared eligible or it is not, and the user is informed by e-mail
This step may take a full month due to the time it takes to review technical documents.

3. The user requests a certificate

The user may order an upgraded Air Quality Certificate if the retrofitted device is approved.
When the order is placed, its receipt will be noted on the "summary" page.