Section 13(12)(iii) in Uttar Pradesh Value Added Tax Act, 2008
(iii)where during the process of manufacture of any taxable goods any exempt goods are produced as by-product or waste-product, it shall be deemed that purchased goods have been used in the manufacture of taxable goods. Conversely, where during the process of manufacture of any exempt goods any taxable goods are produced as by-product or waste-product; it shall be deemed that purchased goods have been used in the manufacture of exempt goods.