9902.01.26 - Dioxosilane (Silicon dioxide amorphous) (CAS No. 7631-86-9) entirely spherical micro-spheres of mean particle size of 0.005 mm or smaller, uniform particle size with a uniformity coefficient of 1.65 or less, trace metal impurities less than 70 ppm, specific electrical resistance of 50,000 Ohm cm (provided for in subheading 2811.22.10)

This HTS category, 9902.01.26, covers a highly specific form of amorphous silicon dioxide (dioxosilane) with precisely defined physical and purity characteristics. The product is characterized by its entirely spherical micro-spheres, with a mean particle size of 0.005 mm or less and a uniform particle size distribution indicated by a uniformity coefficient of 1.65 or less. Furthermore, stringent purity requirements are stipulated, with trace metal impurities limited to less than 70 ppm and a specific electrical resistance of 50,000 Ohm cm. These specifications are crucial for its intended applications, which often lie in advanced materials or specialized industrial processes.

Unlike the broader categories at the HTS Root level, which encompass a vast array of goods such as live animals or raw materials under Chapters 01 through 98, this category is a temporary provision operating under Section XXII. Its existence signifies a particular regulatory or trade policy measure, as indicated by its placement within Chapter 99, relating to temporary legislation and modifications. Therefore, it is distinct from standard commodity classifications and is typically subject to specific conditions or durations of application.

As this is a leaf node within the HTS database, there are no further subcategories branching from 9902.01.26. The classification is definitive for products meeting all the described technical parameters. This underscores the importance of detailed product specifications when classifying goods under such specialized provisions. Importers and exporters must carefully verify that their dioxosilane meets *all* the stipulated criteria, including particle size, uniformity, trace metal content, and electrical resistance, to ensure correct classification and compliance.