gst scrap waste paper

Hi everyone,

                         Question regarding treatment of Wastage 

  We have a printing press and have a duty free stock of paper as on 30.06.2017 the duty forgone on this paper was 6%, on 01.07.2017 at the time of production a wastage generated . So please let me know whether i have paid duty forgone or we have pay IGST @ 12% at the time of scrap sale.  Urgently need please reply as soon as possible.