3606.90 - Other:

HTS code 3606.90 encompasses articles of combustible materials, excluding those specifically defined as fuels for lighters. This category acts as a residual for combustible preparations and articles that do not fit into more specific classifications within Chapter 36. The primary distinction from its sibling, 3606.10, lies in the intended use and containerization of the combustible material; 3606.10 is exclusively for liquid or liquefied-gas fuels packaged for refilling lighters, whereas 3606.90 covers a broader range of combustible articles.

Within this residual category, further subclassification is necessary to delineate specific types of combustible materials. These include ferrocerium and other pyrophoric alloys, which are crucial for their ability to ignite readily when struck. Metaldehyde, a solid form of a chemical compound, is also classified here due to its combustible properties, often used as a pesticide. Finally, the "Other" subcategory (3606.90.80.00) serves as a catch-all for any remaining combustible articles not otherwise specified, requiring careful examination against the chapter notes and other HTS provisions to ensure correct placement.