One of the most common household hazardous wastes is unused paint. Or is it? While oil-based paints and stains, as well as leaded paints and cans that have held leaded paint, are considered household hazardous waste and must be disposed of at an appropriate facility or event, latex, acrylic, and water-based paints can all be disposed of in a much easier manner.
Choose a location that is well-ventilated, but which is also out of the way of children, pets and other animals, and the elements.
Remove the lid from the paint can. OPTIONAL: Add cat litter or sawdust to the paint to reduce drying time.
Allow enough time to dry. The paint will have a rubbery, plastic feel to it. Make sure the paint is dry all of the way through.
That is it! Once the paint is dry, it no longer poses a threat as a household hazardous waste and can be discarded in your regular waste collection service.
However, please remember that oil- and solvent-based paints should never be discarded as regular garbage, even if dry.
Paint (spray can)
Spray paint can be disposed of through drying and discarding. Using a disposable drop cloth or a piece of cardboard, the remaining paint can be safely expelled from the can and dried prior to disposal. As with above, this only applies for latex, acrylic, and water-based paints.
How do you know when the spray can is exhausted? The spray can is exhausted and can be discarded when the aerosol has been completely used. This typically means that the pressure is near the local atmospheric pressure, reducing the potential harm from puncturing the can. Additionally, it usually means that most of the paint has been expelled, as well. There may be some small quantity remaining in the spray can. Combined with the agitator, this residue can make the can feel as though it is not completely empty. However, if the can was used properly, this should not be an issue. If you suspect that there is still pressure or paint in the can, but the nozzle is no longer discharging, please treat the can as hazardous waste.