Anti-dumping duty on Sulphonated Naphthalene Formaldehyde targets dumped imports, with differentiated rates and a five-year term. A definitive anti-dumping duty targets imports of Sulphonated Naphthalene Formaldehyde from China PR after findings of dumping, material injury and causation. The Government prescribes differentiated duty rates by producer and exporter, specifies tariff classification, unit of measurement and currency basis, requires payment in Indian currency, sets exchange-rate conversion rules tied to the bill-of-entry date, and makes the duty effective for five years from notification.