How to Dispose of Paint

The answer is everyone's favorite: It depends. Some paints are not considered household hazardous waste, but in some cases, you need to dispose of old paint very carefully.

Oil Paint

Oil-based paints are considered Hazardous Household Waste (HHW) and are not suitable for reuse after long storage. The label of an oil-based paint will say "oil-based" or "alkyd," or it will instruct you to clean brushes with mineral spirits or turpentine.

Paints of this type are flammable, toxic and contain harmful solvents, resins and pigments; very old oil-based paints (1978 and before) may also contain lead. For these reasons, oil-based paints must be taken to disposal facilities that accept HHW.

Many communities work to simplify this by holding annual or semi-annual HHW collection days.

Latex Paint

Latex or water-based paint, on the other hand, is not a hazardous waste, and can enjoy many reincarnations after its initial use.

Latex paints are those that clean up with soap and water. They're very common for both interior and exterior painting. Before we go into how latex paints can be disposed of, let's talk about what NOT to do.

Before 1990, about 30 percent of latex paints contained mercury and many exterior latex paints still do. For this and other reasons, latex paints must not be disposed of in liquid form. Do not:

Disposing of paint this way introduces contaminants into the air, soil and ground water that can eventually work their way into the food chain.

Avoid Over-buying

Each year, American consumers toss out 10 percent of the paint they've purchased. The main reason? They simply bought too much paint for their project.

You can avoid that mistake by using an on-line paint calculator to help you pinpoint how much paint your project will require. Two recommended sites are Ace Paint Estimator and PainterForum.com [source: Paints & Coatings Resource Center].

If stored properly, paint will last for years. According to the National Paint and Coatings Association, you should:

So, before you throw out that old paint, see if you can use it for another project around the house. This might include making touch-ups to finished paint jobs. But you can reach farther than that with a little imagination.

Create a flow in your home by carrying the color of one room into the next with painted accessories. Picture frames, outlet covers, or clay planters are ideal for tying rooms together through color. You can give an old piece of furniture a fresh look, or even use old paint as primer for a new painted project.

If you can't think of any use for your leftover paint, see if someone else can.

"Individuals with old paint should contact their local Keep America Beautiful affiliate to find out if they would take paint donations for graffiti cleanups, or contact their local chapter of Habitat for Humanity," advises environmental educator Denise Carleton of Reaping Nature Productions.

Plenty of other local organizations would be happy to accept your leftover, usable paint. Art teachers, summer camps, and non-profit organizations such as Boy Scouts, 4-H and the Salvation Army can use a potpourri of paint colors for murals, activities, service projects and to spruce up donated items. High school or community theatre groups can use it for stage sets.

Just make sure they know to limit the use of exterior paints to well-ventilated outdoor projects. You can also check with local government departments such as parks, buildings and maintenance, fire departments, military bases or prisons to see if they're interested in free paint.

Recycling your old paint might be another option. Through partnership with the Product Stewardship Institute, some states have recently passed or are considering legislation to require paint manufacturers to collect leftover residential paint for post-consumer use.

Even if this program hasn't reached your state, you can ask your local paint dealer to help you repurpose your excess paint.

Start by filtering out solids like thickened paint and brush bristles. Then separate the cans into light colors and dark colors. With the help of your paint professional, light colored paints can be combined and re-tinted to a fresh, new color. Empty paint cans are recyclable, too, just like food and drink cans.

Paint Disposal

If all else fails and you must dispose of your old latex paint, turn it into solid waste. If there's less than one-fourth of the paint in the can, take it outside, place it where kids and pets can't get to it, remove the lid and let the remaining paint air dry.

When the paint is hard, you can put the cans out with the rest of your trash. You may need to leave the lids off to show your trash collector that the can is safe for collection.

For larger quantities of paint, brush or roll the paint onto layers of newspaper or cardboard. When the paint dries, put the paper in the trash bin.

Alternatively, you can pour the paint into a cardboard box and mix it with shredded newspaper, cat litter, or a commercial paint hardener to speed solidification. The box can go in the trash when the paint dries, and the paint cans can be recycled.

This article was updated in conjunction with AI technology, then fact-checked and edited by a HowStuffWorks editor.