California Code, Health and Safety Code - HSC § 25143.14

(a) Except as otherwise provided in subdivisions (c) and (d), residues that are removed from equipment for the purpose of cleaning the equipment for continued use are subject to regulation under this chapter only after the residues have been removed from the equipment.

(b) Except as otherwise provided in subdivisions (c) and (d), the act of removing residues from equipment for the purpose of cleaning the equipment for continued use constitutes generation, and not treatment, of a hazardous waste.

(c) Subdivisions (a) and (b) only apply to equipment that is not being used to manage hazardous waste.

(d) Residues that are not hazardous waste, as defined in Section 25117, including residues that are not discarded materials pursuant to subdivision (c) of Section 25124, are not subject to regulation under this chapter.