Painting projects are generally safe and fairly simple for the average homeowner with a bit of DIY know-how. Proper ventilation and clean-up procedures are important to ensure your well-being during a painting project, however. If you are using latex paint, there are certain methods for disposal that are both safe for the environment and in many cases required by law.
Latex Paint Disposal Basics
While latex paint is not considered a hazardous material, it cannot be disposed of unless the cans have completely dried out. There are several methods to dry out cans of latex paint, depending on how much time you have. The National Paint and Coatings Association states that paint, most of it latex, comprises the largest volume of waste collected by hazardous waste programs throughout the country. When you cannot use up or donate leftover paint, you may be able to dry it out in the can and dispose of it with your regular trash if your waste collection company permits.
To dry out your paint, leave the can open in a warm, dry place. If there is 1 inch or less of paint in the can, it will dry it out within a few days.
Add absorbent materials, such as sawdust or cat litter, to the paint if there is more than just a little left. Stir it periodically to hasten drying.
Pour paint from a full can into other cans or containers, a little in each, so it dries quickly.
Buy some commercial paint hardener or dryer to dry paint in a hurry. This is available at many paint and hardware stores as a highly absorbent powder. When mixed with paint as directed, it will dry even large amounts within a day or two.
Leave the lids off the dried paint cans when you put them out in the trash. If you leave them closed, the trash collectors might assume they are not dried out and will leave them behind.
Check Local Programs and Laws
Before moving forward with any disposal methods, call your local government to see if they have a donation program for unwanted paint. If you have quite a bit of paint, it is better to donate it than to throw it away. Many cities have a hazardous waste collection day and may include paint in their list of permitted pickup items.
Do not be tempted to flush excess paint down the toilet or a sink--not only is this damaging to your water supply and your plumbing, but it is illegal in some areas. It can be very harmful to plants and animals further along in the ecosystem, as well.