Toll smelting of copper anode slime: import exemption limits customs duty to toll costs plus insurance and freight. Exempts from basic, additional and special additional customs duty gold or silver produced from copper anode slime exported for toll smelting or processing, to the extent duties exceed the value equal to toll smelting/processing costs (labour, material excluding exported goods, other payable charges) plus insurance and freight both ways, subject to import within one year of export and evidence that the imported metal was obtained from the exported copper anode slime.