If you've had cans of liquid color for several years, the contents haven't necessarily expired. Paint can last for a decade or longer with proper storage. Look at the can and the paint to determine when it's time for disposal. Oil and latex paints require different disposal methods when the time comes, regardless of sheen or whether they're interior or exterior grade.

15 Years for Solvent-Based Paints

Solvent-based paints -- oil or alkyd paints, for example -- last up to 15 years, explains the Bob Vila website. If you open a can of old solvent paint and find a dry layer or skin on top, skim off the dried paint. Likely the paint underneath is still usable after a good stir.

Although you can wrap empty paint cans or those containing hardened solvent-based paint with several plastic bags and put them in the garbage, liquid contents require more attention. To get rid of paint that's still usable, donate it to a local theater or community housing group, or one that handles repurposed building materials. If it's unusable, recycle it with a paint disposal service or take it to a local hazardous waste collection facility.

10 Years for Latex Paints

Latex or water-based paint lasts up to 10 years. If it's lumpy, dispose of it by mixing the contents with enough cat litter, wood chips or sawdust to absorb the liquid, and put it in the garbage when it's dry. Alternatively, mix expired paint with an additive that's designed to turn it into a solid.

Lumps suggest that the paint is too old to use or it reached a temperature beyond the manufacturer's recommendation for storage -- check the label for the storage temperature range, which may be between 60 and 80 degrees Fahrenheit. If you use paint after it has frozen, and then thawed, for example, it can leave a bumpy or grainy texture, or peel.

Put a Lid on It -- Properly

To make any house paint last as long as possible, store it correctly. Beyond keeping it out of sunlight and from freezing, protect your paint by replacing the lid correctly:

  • Lay plastic wrap over the can, tucking it down to the paint level before replacing the lid. If the can is rusty, transfer good paint to another container or dispose of contaminated paint with particles on the surface.
  • To close the can's lid, don't whack it with a hammer directly as this causes dents that break the seal. Instead, place a short piece of one-by-four, plywood or a flat paint-stirring stick over the lid, and hit that, or use a rubber mallet.
  • Store the can upside down for an airtight seal.
  • Write the date on the top or bottom of the cans, so that years later, you'll know roughly when the product has reached its expiration limit.