Know The Paint You Have
Household paints fall into one of two general categories:
- Latex, in which the major liquid ingredient is water.
- Alkyd or oil-based, which contains some sort of solvent. If you're unsure, check the cleanup instructions on the label.
Latex products can be cleaned up with soap and water; cleanup of alkyd products requires paint thinner or mineral spirits. The great majority of today's household paints, 75 to 80%, are water-based latex formulations. Most of these latex paints can be disposed of by pouring the residual paint on an absorbent material, such as cat box filler (kitty litter) or shredded paper; let the mixture dry completely, and dispose of it in your regular trash.
Generally, once you have used up the latex paint, a thin film of paint can be left in the paint can to dry. Do this in an area out of reach of children and pets with the lid off. The cans, with completely dried latex paint film, may then be disposed of with your household trash or recycled in a steel can recycling program.
Alkyd or Oil Based Paint
Alkyd (solvent-containing) paints need special handling, as do products such as paint thinners and strippers, many stains and wood preservatives, turpentine, and mineral spirits. Thinners and turpentine can be reused if you let any paint particles settle to the bottom, and then pour the clear liquid off into a separate, clean container with a lid and clearly mark the new container.
Discard the leftover residue when dry; you can help this drying process by adding cat box filler and then throwing the dried material away with your trash. When it's time to dispose of solvent paint products, save them tightly covered and away from heat or flame sources for a special household hazardous waste collection day.