3827.65.00.00 - Other, not included in the subheadings above, containing 20 percent or more by mass of difluoromethane (HFC-32) and 20 percent or more by mass of pentafluoroethane (HFC-125)

This HTS classification covers mixtures of halogenated derivatives of methane, ethane, or propane that are not elsewhere specified. Specifically, it applies to such mixtures containing at least 20 percent by mass of difluoromethane (commonly known as HFC-32) and at least 20 percent by mass of pentafluoroethane (commonly known as HFC-125). These are typically formulated refrigerant blends used in various cooling applications, distinguishing themselves by the precise combination and concentration of these hydrofluorocarbons.

This subheading differentiates itself from its siblings by the specific dual threshold requirement of both HFC-32 and HFC-125 each comprising 20 percent or more by mass. For instance, 3827.62.00.00 and 3827.63.00.00 focus on higher percentages of HFC-125 without the specified minimum of HFC-32, while 3827.64.00.00 has a different primary component (HFC-134a) and a specific exclusion. The absence of unsaturated fluorinated derivatives of acyclic hydrocarbons (HFOs) is a common characteristic across several related subheadings, reinforcing the focus on specific HFC compositions.

As a leaf node, this classification has no further subdivisions. Therefore, accurate classification under this subheading hinges entirely on meeting the stated percentage requirements for both difluoromethane (HFC-32) and pentafluoroethane (HFC-125). Importers and exporters must ensure that analytical documentation confirms these concentrations to correctly classify the product, preventing misclassification and potential duty discrepancies.