An important characteristic for a material that comes into contact with ground- and surface water is its resistance to leaching. An extensive examination was conducted to establish  whether the used raw materials, such as fly ashes, colour pigments and other fillers could leach. Thio Material was tested in accordance with the Dutch Soil Decree for building materials. The results did not show any leaching. The different kinds of elementary sulphur are insoluble in cold as well as in hot water, not any more than in the ground or in groundwater. By its hydrophobic behaviour sulphur creates such a closed structure, that it even succeeds in binding the polluted raw materials and in avoiding leaching out. The same test was also made on a number of heavy metals.

•  Research centre: SGS Intron (NL)
• Tested in accordance with : SQD (according to the Dutch Building Materials Resolution