Paint Filter Disposal

Q. I am a new environmental coordinator at a manufacturing facility and find you column valuable. Hopefully, you can help me with this issue. Recently, we installed a paint booth for a new product that we are fabricating. We will soon be needing to change these filters and dispose of them. I have been told that since they are fiberglass, they cannot be landfilled since they are hazardous waste, but if we switched to a paper or polyester filter media, they can go to the sanitary landfill as non-hazardous waste. I have also heard that the hazardous waste in exhaust filters is related to the solvent and/or heavy metal content in the filters, and if the solvent is baked out of the filters prior to disposal, the filters are no longer considered a hazardous waste. I am confused. S.B.

A. From an EPA hazardous waste standpoint, discarded paint filters are hazardous waste only if they met one of the characteristics of a hazardous waste—corrosive, ignitable, reactive and Toxicity Characteristic Leaching Procedure (TCLP). Based upon the chemistries of the paint, resins and solvents, it is highly unlikely that discarded paint filters would be corrosive or reactive.

Since the definition of a solid ignitable waste (40 CFR 261.21) includes “is capable, under standard temperature and pressure, of causing fire through friction, absorption of moisture or the spontaneous chemical changes and, when ignited, burns so vigorously and persistently that it creates a hazard,” discarded paint booth filters could meet this definition. However, due to the vagueness of “burns so vigorously and persistently that it creates a hazard,” you can be at the mercy of the analytical lab. Also, ignition and burning could also be a function of the filter media. Before any analysis is conducted, work with your analytical lab to determine what testing procedure is most appropriate for your waste.

Since paints still contain metals and solvents, the TCLP would need to be performed and its leaching solution analyzed for those heavy metals and solvents covered by the TCLP characteristic. Review the material safety data sheets (MSDS) of your paints and solvents with the analytical lab to determine which constituents to analyze. Even if the discarded paint booth filters do not meet any of the EPA RCRA hazardous waste characteristics, there may be more stringent state requirements, and the sanitary landfill may have its own acceptability limitations.

The bottom line is that as a generator it is your responsibility to characterize your waste based upon knowledge of process, process chemicals, and analysis and, then, to document your characterization.

Lastly, it is illegal to bake the discarded paint booth filters if they are RCRA hazardous waste before baking and a non-hazardous waste afterwards unless you apply for and receive a Part B hazardous waste treatment permit. Since you are changing the regulatory status of the waste, EPA considers it “treatment.” However, if the waste filters are non-hazardous before baking, and you bake them to make them acceptable for sanitary landfill, then baking is not an issue.
Hope this has helped.