Excise duty cap on polypropylene staple fibres: excess duty exempted, imposing a per unit limit and temporary relief. Exempts polypropylene staple fibre, tow and tops from excise duty to the extent that duty exceeds the amount calculated at the rate of rupees five per kilogram, effectively capping excise liability for those products; the exemption is time limited and issued under rule 8(1) of the Central Excise Rules, 1944.