The present Ordinance lays down measures relating to the reduction of the discharge of the hazardous substance PM10 into the air in order to improve the air quality. Article 4 establishes that motors and machines may only be used if they avail themselves of a cleansing system aimed at eliminating hazardous particles. The text consists of 13 articles divided into 3 Parts as follows: General provisions (I); General measures (II); Final provisions (III).