Extract residues (coal), naphthalene oil alk., distn. overheads; Naphthalene Oil Extract Residue; [The distillate from alkali-washed naphthalene oil having an approximate distillation range of 180 °C to 220 °C (356 °F to 428 °F). Composed primarily of naphthalene, alkylbenzenes, indene and indan.]