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Unknown Hazardous Waste: Identification, Management, and Prevention

January 27, 2015

A Guide to Dealing With Unknown Hazardous Waste

The Consequences and Causes of Unknown Waste

Unknown hazardous waste containers are the bane of existence for generators and Environmental Protection Agency (EPA) inspectors alike. For generators, this is because unknown wastes require careful precautions and must be analyzed, or at least narrowed down by type, before they can be properly treated or disposed of. For EPA inspectors, unknown waste containers—which may be leaking or might possibly contaminate other wastes—can be a legitimate Resource Conservation and Recovery Act (RCRA) violation for the facility in which the wastes have been stored or generated.

Unknown hazardous waste can also be the result of abandoned wastes, which unlabeled wastes that have been dumped on an owner’s property without permission. These wastes could be left behind by previous owners when a new facility is purchased, or merely deserted on an existing facility’s premises illegally. Neither of these outcomes are good for the new generator.

Unknown hazardous waste container

Because of the extra precautions involved in dealing with unknown wastes and the associated safety concerns, more stringent rules are applied to unknowns, including, a prohibition of transportation by federal, state, and local agencies, and costlier fees for analysis and removal if the waste is not first identified.

Likewise, some treatment, storage, and disposal facilities (TSDFs) or hazardous waste disposal companies will not receive unknown hazardous waste. But sending a samples of the wastes to a laboratory for analysis can cost up to the thousands. So that’s why we’ve compiled a quick checklist to help you identify your containers of unknown chemical waste.


Here are some suggestions for identifying unknown wastes which have been generated on-site.

  • Ask your site manager or supervisor, or waste-working personnel, what kinds of wastes have typically been stored in the areas where the unknown hazardous waste has been found. Someone may recall the identity of the adjacent unlabeled waste.
  • Conduct a pH test of the substance to rule out certain waste types.
  • Check fresh reagents which are present, as the waste could possibly be derived from the reagents. The possible list of wastes can be drastically reduced by knowing this information.

If you cannot ascertain the identity of the waste after following these tips, you can call a local laboratory to have the chemicals tested for their molecular structure, which will give you the best picture of what you have on your hands. Or you can consult a hazardous waste disposal company that handles unknowns for their pricing on analysis and removal.

If you choose the all-inclusive disposal route, it’s best to look for a disposal company that will follow EPA-complaint procedures on unknown wastes; that is, be certain that they will send a certified team to take a small sample the waste, properly identify its contents, and remove the hazardous waste from the facility under Department of Transportation (DOT) and RCRA regulation.

Management & Prevention

Once you have disposed of your unknowns, the next step should to prevent future waste streams from falling into unknown status.

Here are five precautionary management and prevention measures you can take:

  • Label all waste containers, from 55-gallon drums of waste to test tubes.
  • Keep accurate and up-to-date records and inventories.
  • Label all wastes by their full chemical names, not by abbreviations or chemical structure.
  • Set aside distinct zones for discrete types of wastes, and date those containers in these segregated accumulation areas.
  • Ask all workers to identify containers before leaving an area, at least in a temporary or ad hoc fashion, until the wastes are fully accumulated and can be labeled permanently for storage.

By following these preemptive action points, you can avert the consequences of having non-compliant, unknown hazardous containers on-site at your facility.

Dealing with unknown waste can be a burden. But we’re to help lessen the weight on your shoulders—so give us a call at 800-936-2311 and speak with an expert today about any questions you may have regarding the process of identifying and disposing of your unknown hazardous waste. Or, if you prefer, click here to email us.

Disposal of hazardous waste doesn’t have to be painful.