(a) if the whole or any part of the goods resulting from such operations are exported, import duty shall be remitted on the quantity of the warehoused goods contained in so much of the waste or refuse as has arisen from the opera- tions carried on in relation to the goods exported: Provided that such waste or refuse is either destroyed or duty is paid on such waste or refuse as if it had been imported into India in that form;

(b) if the whole or any part of the goods resulting from such operations are cleared from the warehouse for home con- sumption, import duty shall be charged on the quantity of the warehoused goods contained in so much of the waste or refuse as has arisen from the operations carried on in relation to the goods cleared for home consumption.