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Crucial Considerations for Consolidating Your Hazardous Waste Streams

May 16, 2017

Consolidating the waste streams entering your accumulation areas is one obvious way to reduce your hazardous waste disposal costs. Consider:

  • Combining compatible waste materials into larger shipping containers reduces the number of units you need to ship, commensurately lowering your handling and transportation outlays.
  • The fewer containers you handle and transport, the fewer units there are to be inspected, which lowers your compliance liability (should one or more of them fail to meet regulatory guidelines).

Bear in mind, however, that waste stream consolidation is yet another area of hazardous waste management that demands expert consultation. Why?

Mixing one kind of waste haphazardly with another can generate dangerous chemical reactions—along with any number of applicable government fines and sanctions that will dwarf any potential savings you were hoping to achieve.

So Which Doesn’t Go With What?

Some chemical constituents of hazardous waste shouldn’t be nearby each other let alone in the same container; and not knowing which is incompatible with what can make for an unhappy surprise.

Let’s begin with that ubiquitous and seemingly innocent component of hazardous waste: water.

Mixed with sodium hydride or alkali metals such as sodium or potassium, plain old water will generate flammable hydrogen gas. Or mix it with sodium phosphide, and expect highly toxic phosphine gas.

Another seemingly innocuous example: mixing an acid so mild that we sprinkle it on our salads—vinegar—with something as relatively benign as household bleach—Clorox®—will generate highly toxic chlorine gas.

So if you don’t have an in-house chemist on board, and maybe even if you do, prudence demands expert consultation. Some other examples:

  • Acids in combination with cyanide salts or solutions will give off highly toxic hydrogen cyanide; and in the presence of sulfide salts or solutions, acids will yield similarly toxic hydrogen sulfide gas.
  • Ammonia mixed with chlorine (again, simple household bleach) will generate chloramine vapor.
  • Hydrogen peroxide may spontaneously detonate in the presence of sulfuric acid.

Purposeful Fuel Blending

Obviously, you must guard against chemical reactions that are uncontrolled and unanticipated. However, the purposeful mixing of different waste streams to induce specific chemical reactions is a recognized treatment method for hazardous material disposal and management. 

This is called fuel blending, wherein such chemical reactions might be instigated to neutralize the hazardous waste material. This renders it less dangerous and thereby easier to store, transport, and ultimately dispose. Other reasons might to recover energy or material resources from the waste; or to have it meet specifications for an industrial furnace, cement kiln, or incinerator.

A Word about Incidental Reduction

Incidental reduction refers to the situation wherein you combine waste streams with no intention of creating a specific chemical reaction, but the resulting mixture no longer exhibits the same physical or chemical characteristics as did the individual wastes prior to your mixing them.

In such a situation, the resulting waste will still need to be treated for the individual wastes that were consolidated—even if a chemical analysis proves that one or more waste characteristics have been eliminated in the consolidation process.

Seek Expert Advice about Hazardous Waste Disposal

Unfortunately, neither fuel blending nor incidental reduction is specifically defined in EPA rules. Requirements vary by state and localities. (In general, fuel blending requires a hazardous waste installation and operation permit for storage and treatment).


Consolidating waste streams as a part of your hazardous waste removal efforts can make sound economic sense.However, the legal and financial consequences of unplanned and uncontrolled chemical reactions demand expert advice and careful execution.

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