9902.01.21 - Sodium, containing not more than 200 ppm of calcium (CAS No. 7440-23-5) (provided for in subheading 2805.11.00)

This HTS category, 9902.01.21, pertains to specific forms of sodium metal that meet stringent purity requirements, containing no more than 200 parts per million of calcium. The CAS number 7440-23-5 confirms this is elemental sodium. Crucially, this provision is a temporary modification and is provided for under the more general classification of alkali metals in subheading 2805.11.00. This means the goods are subject to additional, temporary restrictions or conditions beyond their basic chemical classification.

Within the broader Chapter 99, which covers temporary legislation and trade agreement modifications, this particular code signifies a specific instance of such a provision. Unlike the primary HTS chapters that classify goods based on their inherent nature and intended use (e.g., live animals in Chapter 1, chemicals in Chapter 28), Chapter 99 codes introduce temporary rules, often related to quotas, duties, or specific import requirements, that overlay or modify the standard classifications.

As a leaf node, HTS 9902.01.21 does not have further subdivisions. Its classification is highly specific, focusing on both the chemical identity (sodium) and a precise purity threshold (calcium content). This level of detail is intended to capture goods that are subject to unique trade policy considerations, distinct from other forms of sodium or other alkali metals that may not have the same restrictions or requirements under current trade agreements or legislative measures.