Since paint contains harmful substances that are dangerous to our health and environment, leftover paint is considered hazardous waste. If it ends up in the landfill, it can leach heavy metals, such as mercury, lead, and cadmium, and toxic chemicals in the soil and groundwater. To protect the environment and public health, paint needs to be disposed of responsibly.
Handling Paint Waste
Disposing of paint is a very important topic not only for paint fabricators, painting contractors, and other businesses that use paint, but also for homeowners.
If you have primers, paint, or paint solvents that you no longer use, you need to determine if they’re hazardous or non-hazardous BEFORE disposing of them. To help businesses and homeowners classify waste correctly, the Unites States Environmental Protection Agency (EPA) indicates two ways in which waste materials can be categorized as hazardous: 1) waste that appears on the lists published on EPA’s website; 2) waste that possesses certain characteristics, such as corrosivity, ignitability, toxicity, and reactivity.
Coming down to disposing of paint, you can reduce the amount of leftover paint by:
- purchasing only the paint you need;
- returning unopened containers to your vendor;
- keeping it for future projects; for instance, solvent-based paints remain usable for 15 years, while latex paint has a 10-year shelf life;
- giving it to someone else who can use it.
If paint can’t be used or recycled, it must be sent to a permitted hazardous waste facility for disposal. Under no circumstances should you throw paint cans into the dumpster or pour paint down the drain. If this occurs, the chemicals and heavy metals from the paint could be discharged into soil and groundwater, and cause contamination. Even if paint is disposed of in closed cans, it may be released when trash is compacted. For this reason, trash collectors don’t accept paint cans, unless they’re empty and dry.
Though disposing of paint is difficult, you can employ a very simple method, especially if you have a small quantity of leftover paint: let it evaporate and dry. For this, you have to find an area with adequate ventilation (e.g. a locked, well-ventilated garage) to store the paint. Ventilation is important to prevent solvent vapor buildup, which is a health and fire hazard. Then, store your paint cans, remove their lids, and allow solvents to evaporate. Depending on the type and amount of paint in cans, it can take anywhere from several days to months for the paint to dry out and turn into a solid rubbery block.
Disposing of Paint-Related Waste
We cannot talk about disposing of paint without mentioning solvents, rags, and wipers. Also considered hazardous waste due to the chemicals they contain, such as acetone, methylene chloride, toluene, and xylene, solvents, rags, and wipers must also be sent to hazardous waste facilities. Alternatively, you can let solvents evaporate similarly to paint and send solvent-contaminated rags and wipers to a dry cleaner. According to EPA, dry-cleaned rags and wipers are no longer considered hazardous waste and can be placed in the trash.
Since this post doesn’t cover all the requirements for disposing of paint and paint-related waste, you should contact your regional Office of Compliance Assistance and Pollution Prevention (OCAPP) for more information. Additionally, if you’ve painted your own company, it’s imperative that you keep information on file to demonstrate how you determined whether paint-related waste was hazardous or non-hazardous. You’ll need this information if the Division of Hazardous Waste Management (DHWM) inspects your business.