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.
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.