In October, 2003, PharmEcology Associates, LLC, requested clarification of a 1994 EPA Hotline interpretation which stated that epinephrine remaining in a discarded syringe would not be classified as a listed hazardous waste. The two areas of clarification were: does that interpretation extend to other P and U listed wastes other than epinephrine; what is the definition of the term "dispensing instrument" and does it extend beyond syringes? In a verbal discussion July 27th, 2004 with Kristina Meson, Environmental Protection Specialist, Office of Solid Waste, USEPA, Charlotte Smith, president of PharmEcology Associates received official assurance that this interpretation does extend to other P and U listed wastes remaining in a used syringe. The P-list of hazardous wastes applies to unused discarded commercial chemical products. Drug residues often remain in a dispensing instrument after the instrument is used to administer medication. EPA considers such residues remaining in a dispensing instrument to have been used for their intended purpose. The residue remaining in the syringe, therefore, is not a commercial chemical product and not a P- or U-listed waste. The epinephrine could be a RCRA hazardous waste, however, if it exhibits a characteristic of hazardous waste. The definition of a "dispensing instrument" is still under review and will be forthcoming.

In a reiteration of the exclusion of P and U listed chemicals from regulation if they were listed for ignitability, reactivity or corrosivity and do not exhibit that characteristic in the generated waste, all forms of medicinal nitroglycerin are excluded as P-listed waste so long as the nitroglycerin is not reactive in the finished dosage forms. But even if the waste is no longer a P-listed waste, it must still be evaluated for ignitability, as some waste IVs and aerosols meet the ignitability characteristic definition. If such a waste met the ignitability characteristic definition, the waste would be a characteristic hazardous waste (D001) and subject to all hazardous waste regulations, including LDR (Land Disposal Restriction) requirements. If the waste is not ignitable, the waste is a solid waste and may be disposed of as such. Bear in mind that states with EPA-authorized RCRA programs were not required to adopt the 2002 revision to the mixture and derived-from rule. Therefore, healthcare organizations should check with their state agency to determine if they have adopted the 2002 mixture and derived-from revision and the current status of waste medicinal nitroglycerin.