The disposal of such material is relieved if the material has not been subject to any separate process, or has not been chemically altered, between its extraction and disposal.
Mae rhyddhad i waredu deunydd o'r fath os nad yw'r deunydd wedi bod yn destun proses arall, neu heb gael ei addasu'n gemegol, rhwng yr adeg pryd cafodd ei echdynnu a’i waredu.