Solved! How to Dispose of Mineral Spirits the Right Way

Q: I recently used mineral spirits for a painting project, but now I’m ready to get rid of them. Pouring solvent down the drain doesn’t seem like a good idea, but I don’t know how to dispose of mineral spirits. What’s the proper procedure for mineral spirits disposal?

A: Just as you can’t dispose of paint thinner by tossing it in the trash or pouring it down the drain, doing so with mineral spirits is also unsafe. There are a few key differences between mineral spirits and paint thinner, but the importance of following proper disposal procedures is common ground for both chemicals.

If poured down the drain, mineral spirits can potentially threaten local wildlife and groundwater. Likewise, you also shouldn’t put mineral spirits, or mineral spirits-soaked rags, in the trash can. Because they have a very low flash point, mineral spirits can cause a fire at temperatures as low as 104 degrees Fahrenheit. Continue reading to learn how to dispose of mineral spirits without threatening the environment or creating a potential fire hazard.

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Used mineral spirits can be filtered and reused.

You may not even need to worry about how to dispose of used mineral spirits. You can actually filter and reuse mineral spirits, eliminating the need to dispose of them altogether. After using mineral spirits for a project, place the used spirits into a clean glass jar. After some time, other substances, such as paint, that are mixed with the spirits will sink to the bottom, leaving pure mineral spirits at the top of the jar. You can then pour the mineral spirits out of the jar and into a separate clean jar for storage (be sure to seal and label the new jar).

Waiting for mineral spirits to separate from other substances may take a long time. In some cases, you could end up waiting months for everything to fully separate. If you want to speed things up a bit, filter the spirits using coffee filters. Wearing nitrile gloves, place a layer of three coffee filters over the mouth of the jar. Use a cotton cord to hold the filters in place. Then, slowly pour the solution through the filters into a clean jar. The coffee filters will collect solid materials and allow the mineral spirits to pass through. Now, you can begin using the mineral spirits right away, if needed.

Take unwanted mineral spirits to your local household hazardous waste facility.

Mineral spirits are classified as a type of hazardous waste. Many cities or counties offer a household hazardous waste facility for residents. If you’re unsure if this service is offered by your community, check with your local government.

Once you locate your nearest hazardous waste facility, contact them to confirm that they offer mineral spirits disposal services. They can also provide you with any other important information, including if there are specific drop-off days, special directions for packaging the mineral spirits, or whether you’ll be charged for mineral spirits disposal.

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Shop rags soaked with mineral spirits should also be treated as hazardous waste. 

When disposing of mineral spirits, don’t forget that the rags or applicators you used will also need to be disposed of properly. Rags that have mineral spirits on them are also considered hazardous waste. Just like mineral spirits, contaminated rags also pose a risk to the environment and can easily combust.

For these reasons, you should dispose of the rags along with the mineral spirits. If you plan to take your old mineral spirits to a hazardous waste facility, take the used rags along with you, as well.

You can also purchase an oily waste disposal can and collect mineral-spirit soaked rags inside until you can take them to a hazardous waste facility. These special cans, which are made from galvanized steel, are designed to prevent materials from combusting.

Completely empty and dry mineral spirits containers can be recycled or thrown away.

When it comes to how to get rid of mineral spirits containers, it’s an even simpler process. In some cases, you can safely recycle or throw out empty containers that once held mineral spirits.

Before placing the empty containers out for pickup with your trash or recycling, there are two important criteria that must be met, though. First, you must ensure that there is no more than 1 inch of paint sludge left in the container. Second, the container must be fully dry before you dispose of it.

Keep in mind that every municipality has its own rules. Before putting empty mineral spirit containers in the trash or recycling, confirm that there are no rules against it in your area.