2903.74.01.00 - Chlorodifluoroethanes (HCFC-142, 142b)

This HTS category, 2903.74.01.00, specifically classifies chlorodifluoroethanes, commonly known by their HCFC designations such as HCFC-142 and HCFC-142b. These are halogenated hydrocarbons belonging to the broader group of acyclic hydrocarbons containing at least two different halogen atoms. Their chemical structure involves ethane molecules where hydrogen atoms have been substituted by chlorine and fluorine.

Distinguishing this category from its siblings is crucial for accurate classification. For instance, 2903.71.01.00 covers chlorodifluoromethane (HCFC-22), which is a methane-based compound, not ethane. Similarly, categories like 2903.72.01.00 (Dichlorotrifluoroethanes) and 2903.73.01.00 (Dichlorofluoroethanes) involve different combinations and numbers of chlorine and fluorine atoms attached to the ethane backbone. This specific classification hinges on the precise molecular composition, where two chlorine atoms and one fluorine atom are present, or one chlorine and two fluorine atoms, attached to the ethane structure, thus defining chlorodifluoroethanes.

As this is a leaf node within the HTS, there are no further subcategories. Classification under 2903.74.01.00 is definitive for substances that are exclusively chlorodifluoroethanes. Importers and exporters should confirm the exact chemical identity and composition to ensure correct tariff placement, as variations in halogenation or the parent hydrocarbon chain would lead to classification under a different HTS code.