Excise Matter Textile - Urgent

We are manufacture of "POLYESTER TEXTURISED YARN" falling under CSH No. "54023300" and we are opting Exemption Notification No. 30/2004-CE dated 09/07/2004.During the cource of manufacturing "POLYESTER TEXTURISED YARN WASTE" falling under CSH No. "55051090" generate.

Q-1.       We cleared our Final Goods"POLYESTER TEXTURISED YARN" at Nil Rate of duty but at                   what rate we cleared our by product "POLYESTER TEXTURISED YARN WASTE" wather it                 at nil rate of duty or dutiable and if Nil Rate of duty Why?