Ostendorf Kunststoffe. Skolan Safe. Silent waste pipes and fittings are made of mineral-reinforced polypropylene. The specifications apply to DIN EN 1451-1 in combination with DIN 19560-10. Manufactured in accordance with Z-42,1-217. Given the excellent mechanical and acoustic properties, this system is suitable for all building applications. Colour light grey RAL 7035. Skolan Safe pipes and fittings are quality assured and subject to regular quality control. Quality management according to DIN EN ISO 9001, environment.