Chemicals used in industry, science and photography, as well as in agriculture, horticulture and forestry, filtering materials namely chemical products or vegetable substances, such as chemical preparations or vegetable substances for detecting microorganisms in suspensions, gases and air, the aforementioned products also applied on foils, sheets or membranes; filtering materials namely chemical substances also applied on foils, sheets or membranes; acid regulators (buffers), whether or not o...