2805.40.00.00 - Mercury

This HTS classification, 2805.40.00.00, specifically covers mercury, a unique metallic element. Mercury is distinguished by its liquid state at room temperature, a characteristic shared by no other metal. It is a heavy, silvery-white liquid that exhibits high electrical conductivity and a low vapor pressure. This classification is distinct from its sibling categories within Heading 2805. Unlike "Alkali or alkaline-earth metals" or "Rare-earth metals, scandium and yttrium," mercury is categorized separately due to its distinct chemical and physical properties, particularly its elemental nature and unusual liquid phase.

As a leaf node within the HTS, 2805.40.00.00 does not have further subcategories. Therefore, the focus for classification purposes within this code is on the identification of mercury itself, regardless of its form (e.g., purified mercury, alloys containing mercury, or mercury compounds if not specifically classified elsewhere). The primary classification criterion is the presence and identification of the element mercury. Common applications that would fall under this code include its use in thermometers, barometers, certain electrical switches, and historically, in dental amalgams, though its use in many of these applications is now restricted due to health and environmental concerns.