Not All Hazardous Drugs Are Created Equal
Has your facility accurately identified all of their hazardous drugs? To accurately answer that question, further context is needed. What do you mean by hazardous drugs? EPA (The Environmental Protection Agency) and the NIOSH (National Institute for Occupational Safety and Health) have two widely different definitions of the criteria of what constitutes a hazardous drug (HD).
EPA views a hazardous drug (waste) if it is the sole active ingredient from their P or U list or it exhibits a specific characteristic of a hazard. Whereas NIOSH defines hazardous drug if it appears on their NIOSH List of Antineoplastic and Other Hazardous Drugs in Healthcare Settings, 2016. Believe it or not, there is very little overlap between the two definitions. Note, NIOSH has made some minor modifications to this list since 2016 and an updated version is anticipated.
Compliance with USP <800> pertains to the handling of NIOSH hazardous drugs in a healthcare setting. However, when it comes time for disposal, USP <800> indicates to follow federal and local regulations for disposal. At the very least, federal means the EPA. That means you may have been handling a NIOSH hazardous drug internally as hazardous, but that same drug, if it does not meet the definition of EPA hazardous can be disposed of as a non-hazardous waste.
As a Best Management Practice (BMP), we recommend disposing of all NIOSH Table 1 hazardous drugs as EPA hazardous.
Note, states can impose even stricter regulations on what they consider to be a hazardous drug. Minnesota is a good example of that. They incorporate an additional waste category called Minnesota Lethal (MN01).