How Long Does Paint Last If Opened?

If you've painted the inside or outside of your home, you probably have old paint lying around. Paint is considered a hazardous material, the same as computers, and shouldn't be thrown away with the regular trash. We've researched how long paint lasts once opened, as well as how to dispose of it, so you don't have to wonder what to do with old paint.

Opened cans of paint have shorter shelf lives than unopened cans. Regardless of paint type, an open can of paint lasts around two years without spoiling if sealed tightly and stored in a cool, dry place. If you do not use the paint within two years of opening, you'll need to test to see if it is still good. It is possible to use paint older than two years, but it is not recommended.

Most of us have leftover paint lying around. It's a good idea to keep the same colors as your walls or other projects in case you need to touch them up. We encourage you to continue reading to learn more about why paint goes bad, how to tell if it is still useable, and how to dispose of paint properly.

Paint cans during house renovation, process of choosing paint for the walls, different colors of white, green and blue on wooden floor, How Long Does Paint Last If Opened

What Causes Paint To Go Bad?

Paint goes bad over time by separating into its solid and liquid parts. Paint is usually made of suspended semi-solids in a liquid base. Temperature and air exposure will speed up the process of these separating, and once separated enough, they will not go back together, rendering the paint unusable. Essentially, paint is usable if its chemical makeup hasn't had time to change too much.

A man opens a jar of white paint with a can opener on a white background. Renovation concept.

Oil-based paints will usually last around fifteen years in unopened cans, while latex and acrylic paints last around ten. This is basically because of the paints' chemical makeup and the way the materials are able to bond together. Due to temperature, air exposure, and time, paints will separate, causing their deterioration. The different chemical bonds are what make it last longer or less time. 

Many people will leave their half-used paint cans in a garage or shed. If you live somewhere extremely cold or hot, the paint will decay even faster. Paint companies used to mix antifreeze into their paints, but this was removed after it was deemed dangerous. Once paint freezes, it will never be useable again. The same goes for extreme heat, as it will break down the paint incredibly quickly. Unopened cans are not immune to harsh temperatures and will suffer the same fate if they are not stored properly.

What happens if you use old paint?

Old paint will quite simply just not work. The application will leave a rough finish, and the paint will very likely crack and peel. Fumes from old paint are also an irritant for your eyes, nose, and throat. The fumes can make you sick if you are exposed to them for too long. 

How do you know if your old paint is still good?

Paint cans during house renovation, process of choosing paint for the walls, different colors of white, green and blue on wooden floor

There are a few ways you can test to see if your paint is still good. One way is to open the can and blend it well with a stirring stick. Once you've blended a few minutes, dip a brush into it and brush the paint onto some cardboard. If it goes on smoothly, then the paint is probably still good, but if the paint contains grainy lumps that can't be blended out, it is bad.

If you open the paint and it has visible lumps, that does not automatically mean it is bad. It's possible some of the paint on the edges simply hardened or got mixed in from your brush. Pour the can through a paint strainer to remove the lumps and then test the paint on some cardboard.

Click here for paint strainers on Amazon.

While lumps may be okay sometimes, hard solids are not. If your paint has become solid on the bottom of the can and liquid above, it is not usable. It cannot be shaken back into being useable either. At this point, the paint has almost completely separated, and it needs to be disposed of properly.

Another way to check your paint is to give it a sniff. If it smells foul or rancid, then the paint has gone bad. With no way to salvage paint in this state, dispose of it according to your state's hazardous material laws. 

How do you dispose of old paint?

Old paint cans in front of a garage

Paint is considered a hazardous material, with different types falling under different classifications. You'll need to check your paint type and disposal laws when getting rid of old paint. Usually, you can call the town hall or search online for specified collection sites for toxic materials. Some latex or water-based paints can be disposed of at home, while oil paints must be taken to disposal sites. 

Does Lowes take old paint?

Lowes does not take old paint. According to their website, due to the varying state laws regarding toxic waste disposal, they cannot accept old paints nor recycle them. 

Does Home Depot take old paint?

Home Depot also does not accept old paint. Similar to Lowes, Home Depot has stores in nearly every state, so complying with local disposal laws is too complicated. They simply avoid these complications by refusing to accept or recycle paint.

Does Ace Hardware take old paint?

Ace Hardware does accept old paint at some locations. Check your local Ace Hardware to see if they specifically will recycle paint. If they do accept or recycle old paint, then there will be a small charge for the service.

Does Sherwin Williams recycle old paint?

Old Paint Can with Dried Blue Paint Dripping down Side

Sherwin Williams accepts and recycles oil and latex-based paints, stains, and varnishes. They offer this service at no charge as well. Sherwin Williams works with both PaintCare and Habitat for Humanity to recycle and use paints.

For a great overview of Sherwin Williams paint and its shelf-life, check out our article, "How Long Does Sherwin Williams Paint Last?"

Disposal at Home

It is possible to dispose of old paint yourself properly. One way to dispose of latex paint is to mix cat litter into it. Alternatively, you can use shredded newspaper or sand instead of kitty litter. Once it has set up properly and is solid, you can simply throw it into the garbage. There are commercial paint hardeners available as well if you prefer to go that route. Check with your local laws to make sure this is legal before using this method, however, it is not legal in every state. 

Oil-based paint cannot be disposed of at home. It is considered toxic and must be taken to an appropriate disposal facility. Remember that you can be fined for disposing of toxic materials in the regular trash.

Donating Opened/Used Paint

There are places where you can donate your old paint as well. If it is usable, or right after you've finished your project, consider donating the excess paint to charities like Habitat for Humanity. Instead of wasting the paint or pushing it into a disposal facility, they will make good use of your unused paints in their projects.

Regardless of how you choose to dispose of paints, you should check with your local authorities regarding what is required for disposal. Some states allow you to solidify latex and water-based paints and throw them out, while others do not. Even if it is allowed to solidify the paint at home, you may still be required to bring old paint to proper disposal facilities.  

In Closing

Paint's shelf-life is drastically reduced once the can is opened. Exposure to air, harsh temperatures, and natural separation of the paint can render it unusable. After reading through this article, you should know how to dispose of old paint and how to tell if it is still useable. 

If you're looking for the best paints for certain projects, one of our other articles may be of use to you. Check out:

What Is The Best Paint To Use On Vinyl Siding?

7 Best Paint Choices For A Wood Fence

What Is The Best Paint For Baseboards? [4 Actionable Suggestions]

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