2852 - Inorganic or organic compounds of mercury, whether or not chemically defined, excluding amalgams:

This HTS category, 2852, encompasses inorganic or organic compounds of mercury, regardless of whether they are chemically defined. This includes pure mercury compounds as well as those that are mixtures but still contain mercury. It is crucial to note that amalgams of mercury are explicitly excluded from this classification.

Distinguishing this category from its siblings at the Chapter 28 level is straightforward. Chapter 28 generally covers inorganic chemicals, with specific headings for various elements, compounds, and precious metals. Unlike headings that focus on other specific elements or types of compounds, 2852 is dedicated solely to mercury-based chemical substances. For instance, it is separate from categories covering acids, oxides, or salts of other metals.

Within HTS 2852, two subcategories provide further detail: 2852.10 for "Chemically defined" compounds and 2852.90 for "Other" compounds. The 2852.10 heading is for mercury compounds where the specific chemical formula and structure are known and confirmed. The 2852.90 heading serves as a residual category for mercury compounds that are not chemically defined, which may include mixtures or substances where the precise composition is not fully established but are demonstrably mercury compounds.