1. Member States shall take all necessary measures not entailing disproportionate costs to ensure that concentrations of PM_{2,5} in ambient air do not exceed the target value laid down in Section D of Annex XIV as from the date specified therein.
2. Member States shall ensure that concentrations of PM_{2,5} in ambient air do not exceed the limit value laid down in Section E of Annex XIV throughout their zones and agglomerations as from the date specified therein. Compliance with this requirement shall be assessed in accordance with Annex III.
3. The margin of tolerance laid down in Section E of Annex XIV shall apply in accordance with Article 23(1).