The draft, intended to modify the "Air Protection Ordinance" of 1990, is the occasion to present a survey about the occurring wood residues, waste products, relevant active ingredients emanating from combustion and also the origin of the treated wood and it's possible environmental load in Switzerland. The combustion behaviour of certain active ingredients is specified. Based on the situation analysis regarding waste disposal, a separation between surface treated and pressure impregnated wood has been advanced. In this relation, the former should fall into the "wood combustible range".