The Toulouse Metropolitan area has an emergency low emission zone scheme during high pollution events. It is not decided yet what the measure will look like. But most likely some vehicles will be banned after a certain amount of days with smog alarm. The Crit'Air sticker is necessary to be allowed to circulate during smog alarm.
There are stickers called "air quality certificates" (Certificats qualité de I’air) which are mandatory for French and foreign vehicles.
For vehicles registered in France, the French LEZ stickers can be bought here.
Stickers for foreign vehicles can be bought in English, French, German or Spanish. These stickers can be bought by those outside France. Please allow enough time for delivery.
Please note: Buying stickers from some websites can cost up to 5 times the price, so check carefully, and use official sales websites.
All vehicles can use this webpage to see what sticker their vehicle will receive.
For details see "National Scheme".