Many people end up with unwanted chemicals because they over-purchased in the first place.
Not only is this a waste of your money, but now you have a problem on your hands getting rid of the material. Plan your project carefully, only buy the amounts you know you need and think ahead to any waste you may be generating such as oily rags or contaminated cleaning solvents. At this time in Oklahoma, there is no on-going disposal mechanism for these materials. They really shouldn't go to the landfill. We could end up contaminating our own ground water.