Auxiliary duty exemption on catalysts produced from exported precious metals: claimable subject to production cost, timing and documentary conditions. Exemption from auxiliary duty applies to catalysts containing platinum, palladium or silver produced from exported metal or metal recovered from exported spent catalyst, limited to the portion of duty exceeding an ad valorem threshold representing production or processing costs (labour, materials excluding the exported metal, other production charges) and insurance and freight both ways, subject to conditions: import within the prescribed period, no drawback claimed on export, and sufficient evidence that the catalysts were produced from the exported metal.