When you trash latex paints, make sure they're dried before you toss them.

Are you planning to tackle a DIY painting project or hire a professional painter? Whichever you choose, you’re likely to face the problem of disposing of your leftover paint. To dispose of paint in a responsible (not to mention legal!) way, you’ll have to rule out solutions like tossing a can with wet paint into the trash or pouring it down the drain.

Find safe, healthy guidelines on how to and where to dispose of paint – whether water-based, oil-based or spray paint.

How to Dispose of Latex, Acrylic and Water-Based Paint

To dispose of paint that is latex, acrylic or water-based, follow these guidelines: Use It Up, Pass It On, or Dry It Up.

Use It Up

Calculate carefully and buy only the number of cans you’re likely to need before your paint project. Ask the store about its return policy for unopened cans. Both these steps will cut costs and minimize paint disposal problems. Expect one gallon of paint to cover between 250 and 350 square feet, depending on the condition of the walls and the number of coats you’re applying.

When you do have leftover paint, the last of the can may be just enough to cover a table or shelf. Sometimes the underside of a project needs to be painted and leftovers will do. Combine small quantities of paint with other shades when a coat of paint, but not the color, is important.

Pass It On

Recycle old paint for a practical way to use it up. Community groups, theater troupes, schools ,and perhaps neighbors may appreciate the offer of leftover paint. Local recycling centers often have an area set aside to share partially full, non-rusted cans of paint.

Your city might also host a program for redistributing materials which you no longer want but which someone else might. For instance, Residents of LA County can use the innovative Los Angeles County Materials Exchange site to browse or post various materials.

Often, neighbors or community groups will be grateful for your leftover paint.

Dry It Up

If you decide to dispose of paint in the trash, it must be dried out or hardened. To dry out a can of water-based paint that’s less than a quarter full, simply remove the lid and leave it in a well-ventilated place for a few days. Speed drying of fuller paint containers by adding mulch, kitty litter, shredded paper or a commercial paint hardener.

Some municipalities prefer the paint cans to be separated from the other garbage. You can place the cans beside or on top of the trash container with the lid off so the trash collector can see that they’re empty or dried out.

There is no need to take latex, acrylic and water-based paints to a hazardous waste collection site, as this costs taxpayers money for unnecessary disposal. Some counties recycle paint cans, so check with your local recycling center.

Paint cans can be recycled or dumped at a hazardous waste collection site.

Empty spray paint cans may be thrown out or recycled.

For questions about how to dispose of paint, call your local waste authority or department of public works. Most cities run household hazardous waste disposal programs. There may be occasional neighborhood pick-ups, collection events, or permanent centers for hazardous waste disposal. You can even find ingenious iPhone apps to help you deal with household waste.