goods dutiable under excise or not?

I think you have to refer Central Excise Tariff Act.....

I think the used plastic is not free from duty if some one has utilized it for manufactring or packing any excisable goods. You can see the Chapter Subheading No.39 15 1000 in the Schedules to the Central Excise Tariff Act, 1985.

The Real the question which should be asked by what process the waste materials are obtained. If it can be proved that these are not obtained during manufactring process or has not come out of any cenvated material, it is duty free.

So in case of sweeping material we can say that those are non dutiable but in case of plastics it is dutiable if the same is obtained out of manufacturing or packing process and cenvat/ modvat had been taken on those plastics.

Vijendra