3817 - Mixed alkylbenzenes and mixed alkylnaphthalenes, other than those of heading 2707 or 2902:

Heading 3817 encompasses miscellaneous chemical products primarily consisting of mixed alkylbenzenes and mixed alkylnaphthalenes. These are not pure chemical compounds but rather mixtures of alkylated aromatic hydrocarbons. The "mixed" designation signifies that these products contain a variety of alkyl groups attached to the benzene or naphthalene rings, and the specific composition may vary. They are typically derived from petroleum or coal tar refining processes.

This heading is situated within Chapter 38, which covers a broad range of miscellaneous chemical products that do not fit neatly into other chapters. Unlike sibling categories in Section VI which might classify specific organic chemicals (Chapter 29) or fuels (Chapter 27), heading 3817 deals with mixtures of these aromatic hydrocarbons as industrial intermediates or components in various applications, rather than as primary chemical substances or fuels themselves.

Within heading 3817, further subdivisions exist to differentiate between the primary types of these mixed alkylated aromatics. The subcategories distinguish between "mixed alkylbenzenes" and "mixed alkylnaphthalenes." This distinction is crucial for tariff purposes, as it reflects differences in their chemical structure, properties, and likely end-uses. For example, mixed alkylbenzenes are often used as precursors for detergents, while mixed alkylnaphthalenes might find applications as solvents or heat transfer fluids.