Solvent waste (including thinners, cleaners, degreasers, fuel additives, adhesive removers, etc.) qualifies as Hazardous Waste and cannot be disposed of in the trash or sink.
Once these solvents are no longer usable, the liquid must be placed in a suitable closed container (preferably the original container) and labeled as a Hazardous Waste. These materials must be disposed of through EH&S.
Rags which are used with solvents must be collected and disposed of as a Hazardous Waste.