Are Chemicals of Interest (COIs) in hazardous waste to be counted towards an STQ?
COI’s in solid and hazardous wastes do not count towards the COIs’ STQs, except for wastes described in 40 CFR § 261.33 (e.g. off-specification wastes.) Such wastes are typically designated as P and U code wastes by EPA. Some facilities may receive and use mixed wastes which may contain small and indeterminate amounts of P and U code wastes, as well as many other wastes that need not be counted toward any STQ. However, if a facility possesses a quantity of unblended P or U code waste or other mixed waste primarily containing wastes described in 40 CFR § 261.33, the facility is within the scope of DHS regulations and must count the COI in such wastes to determine if a Top-Screen would be required.
