How to Dispose of Paint Thinner the Right (& Wrong) Way

Disposing of paint thinner properly is essential for the safety of your family and community.

Published March 7, 2023
paint brushes in a cup of paint thinner

If you look in your garage or under your sink right now, you probably have an entire collection of half-used bottles of hazardous chemicals like paint thinner that you swore you'd figure out how to throw away years ago. It's important to know how to dispose of paint thinner properly because it's extremely dangerous and it's not a chemical you want pointlessly lying around your house for years to come.

How to Dispose of Paint Thinner Properly

Paint thinner's classified as a household hazardous waste product that you can use for all sorts of things. Because of how often they use it, artists and contractors alike are well versed in the right way to throw away paint thinner. Given that it's hazardous when ingested and can pollute any waterways it gets into contact with, you should only take it to a Household Hazardous Waste Collection Center. Every state has a varying number of these as well as temporary centers they'll put up at different times throughout the year.

While it might be annoying to drive a distance to throw away your paint thinner or to wait for a few months when a temporary site is ready to go up, it's the only secured way to make sure it doesn't enter the regular waste treatment system.

Fast Fact

Paint thinners are flammable with a flashpoint below 140°F, meaning you should never store it near excessive heat, and always keep it closed tight because the vapors will travel and can catch on fire.

Ways NOT to Get Rid of Paint Thinner

Now that you know the right way, it's essential you also know the wrong way so you don't do it. Do NOT dispose of paint thinner in any of the following ways.

  • Flush it down the toilet.
  • Pour it down the drain.
  • Pour it on the ground outside.
  • Dilute it with water and then pour it outside/down the drain.
  • Throw it away in your regular garbage.
  • Leave it in your recycling.
  • Take it to a landfill.

What's So Dangerous About Paint Thinner?

On top of being flammable, paint thinner is a hazardous substance that causes many harmful effects to the human body. If you inhale the vapors, you can get as little as a headache and as much as convulsions and passing out. Similarly, getting it on your bare skin can cause dermatitis, or getting it in your eyes can cause irritation and burns.

Worst of all is if you happen to swallow some. It'll cause nausea, gastrointestinal irritation, diarrhea, and even up to seizures and death depending on how much you ingest.

Because of all these hazards, the last thing you want to do is transfer the liquid into groundwater, streams, lakes, or the sewage system, as it can travel to some unsuspecting person and endanger them.

Keep Yourself and Others Safe When You Get Rid of Paint Thinner

Household chemicals, no matter how safe they appear, aren't to be taken lightly. There's a proper procedure for getting rid of half-filled or full bottles of paint thinner, and all it involves is you making sure you get the stuff to a designated facility. Although it might seem like overkill, getting rid of paint thinner the right way will keep you and the people around you safe.

How to Dispose of Paint Thinner the Right (& Wrong) Way