There are two types of paints commonly used by homeowners. These include oil-based paint and water-based latex paint. Below are guidelines to follow when disposing of these different types of paint. Please note: it is always best to consult your local rules and regulations before disposing of paint products and other chemical substances.
All oil-based paints must be taken to a household hazardous waste drop-off to be disposed of. Do not dispose of oil-based paint in your regular garbage.
Latex Paint Over 20 Years Old
Latex paints that are over 20 years old may contain lead and therefore must also be disposed of through a hazardous waste drop-off area.
Latex Paint Less Than 20 Years Old
First, you will have to determine whether or not the leftover paint that you have is latex paint.
Look on the label to see if this is specified. If the label has been torn off or is unreadable you can also tell what type of paint you have by how it is thinned or cleaned up. If water will rinse the paint off of your hands and brushes then you have latex paint. If a special product such as paint thinner, a brush cleaner or other solvents must be used then the paint is oil-based. If you can’t decide what type of paint you have then it is best to treat it as an oil-based paint and take it to a hazardous material drop-off.
While Latex paints are less toxic than oil based paints they still have poisonous chemicals in them. Due to the fact that latex paint is often made up of half water, it is easy for these harmful chemicals to seep into the ground, posing a threat to our environment. It is therefore very important that latex paint is left to dry before it is disposed of. Rinsing a small amount of paint off of your hands or brush will not cause any problems however paint should never be poured down any drain or waste water system!
The best way to dry out your leftover latex paint before disposing of it depends on how much you have left in the can.
If there is only a thin film (less than 1/32 of an inch) on the sides of the can then you can simply throw the can out. If it’s a metal can then it can even be recycled.
If there is an inch or so left in the bottom of the can, simply open the lid and leave the can in a well ventilated area to dry. (Please note: it is important that you leave the open paint can in an area where children and animals will not be able to get at it.) Within a few weeks the paint will dry out and harden at which time the whole can can be put out with your regular garbage.
Note: It is important that when putting the paint can out with your regular garbage that you leave the can out for the collector to see. As well, leave the lid off so that your garbage collector can see that the paint is dried and hardened, as haulers will not pick up paint unless they know that it is thoroughly dried latex paint.
In the case that you have a lot of paint left in the can (a pint or more) there are a few tricks that you can use to help the paint dry out faster:
1. Line a box with a plastic bag and pour a thin layer of paint into the box (less than 1 inch). (Keep the box in a well ventilated area where pets and children cannot get into it.) Leave it to dry out and harden. Once the first layer has hardened add another. Repeat this process until all of your leftover paint is hardened then leave the box out with your regular garbage.
If a latex paint can says that it is mildew resistant or preservative it must be disposed of through a hazardous material drop-off site.
Always check your local rules and regulations for disposal procedures for paints and other chemical substances.
Image by Ames247