NAICS 32419 captures petroleum and coal-derived products not classified elsewhere, including petroleum coke (calcined and uncalcined), petroleum waxes, coal-tar pitch, and other residual outputs of refining and coking. The two primary six-digit subdivisions are 324191 (lubricating oils and greases) and 324199 (all other petroleum and coal products).

Calcined petroleum coke — heat-treated to remove moisture and volatile matter — is classified separately from green (uncalcined) coke under the HTS schedule, and the two products serve different end markets: calcined coke goes primarily to aluminum anode and electrode production, while green coke is used as fuel or further processed. Importers should confirm the calcination status with the supplier before filing entry documents, as misclassification can result in duty underpayment or overpayment.