July 11, 2012

Partially Used Containers of P- and U-Listed Chemicals

A bottle of P- or U-listed laboratory chemical is opened and some of the chemical is used. What is the regulatory status of the remaining chemical in the bottle when discarded? What about the bottle itself?

Although we have heard people argue otherwise, the RCRA regs and guidance clearly indicate that the remaining chemical in the bottle would be P- or U-listed when discarded. Section 261.33(c) states that the following materials are considered hazardous waste:

“(c) Any residue remaining in a container or in an inner liner removed from a container that has held any commercial chemical product or manufacturing chemical intermediate having the generic name listed in paragraphs (e) or (f ) of this section [i.e., the P- and U-lists, respectively], unless the container is empty as defined in §261.7(b) of this chapter.”

So, according to §261.33(c), the remaining chemical or residue in the bottle is regulated as P- or U-listed hazardous waste unless the container is rendered “RCRA empty” under §261.7(b). What’s more, the bottle would carry the P- or U-code until it is rendered RCRA empty. If the bottle contained a P-listed chemical, §261.7(b)(3)(i) would require it to be triple rinsed before the container would be RCRA empty and no longer carry the P-code. In addition, any waste (i.e., rinsate) removed during this process would be P-listed hazardous waste. Although the requirements for rendering containers of U-listed chemicals RCRA empty are less-stringent, the same principle applies. That is, a partially full container of U-listed chemical, if discarded, will carry a U-code unless the container meets the definition of “empty” in §261.7(b)(1).

This regulatory language is bolstered by EPA guidance in RO 14656. In this guidance, the agency addressed unused solvent residues in spray cans that are being discarded. According to the agency, if the remaining unused solvent in the spray can is P- or U-listed, it would be a listed hazardous waste when discarded.


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