4805.40.00.00 - Filter paper and paperboard

HTS 4805.40.00.00 specifically classifies filter paper and paperboard. These materials are characterized by their porous structure, designed to allow fluids or gases to pass through while retaining solid particles. This filtration property is their defining characteristic and primary purpose.

This category is distinct from its siblings. For instance, while other categories within 4805 cover fluting paper, testliner, sulfite wrapping paper, and felt paper, these products are not primarily designed for filtration. Fluting and testliner are used in packaging for their structural strength, sulfite wrapping paper for protection and bundling, and felt paper for its absorbency and insulating properties. The key differentiator for 4805.40.00.00 is its specific function as a filtering medium.

As a leaf node, HTS 4805.40.00.00 has no further subcategories. Therefore, classification within this code relies heavily on the intended use and physical attributes that enable filtration. Examples include laboratory filter paper used for scientific analysis, industrial filter media for machinery and air purification systems, and coffee filters. The material composition and manufacturing process are geared towards creating a permeable barrier for separation purposes.