Hazardous industrial waste characteristic wastes

Mineral processing spent materials. Mineral processing generates spent materials that may exhibit hazardous waste characteristics. Common industry practice is to recycle these mineral processing wastes back into the processing operations to recover mineral value. U.S. EPA created a conditional exclusion from the definition of solid waste for these spent materials when recycled in the mineral processing industry, provided the materials are stored in certain types of units and are not accumulated speculatively. 

The fourth characteristic which could make a waste a hazardous waste is toxicity. To determine if a waste is a toxic hazardous waste, a representative sample of the material must be subjected to a test conducted in a certified laboratory. The test procedure used from the inception of the hazardous waste management program was the EP-Toxicity test. The new test procedure is the Toxicity Characteristic Leaching Procedure (TCLP). The TCLP is more aggressive than was the formerly used EP-Toxicity test for certain chemicals. Many industrial wastes which previously were not hazardous wastes may be considered hazardous waste when tested using the new procedure. 

When sodium silicate solutions at or above pH 12.5 become wastes, they are "hazardous wastes only because they exhibit the corrosivity characteristic." Consequently, their dilution or neutralization in accordance with EPA s operating conditions does not require an individual RCRA permit provided, of course, they are not part of an industrial waste stream which has been designated as hazardous (52). It should be noted that, as of this writing, the permit requirement is only suspended, and the permit by rule is not yet in effect. Current EPA regulations should be reviewed concerning further developments and concerning all other applicable requirements. 

Petrochemical recovered oil. Organic chemical manufacturing facilities sometimes recover oil from their organic chemical industry operations. U.S. EPA excluded petrochemical recovered oil from the definition of solid waste when the facility inserts the material into the petroleum-refining process of an associated or adjacent petroleum refinery. Only petrochemical recovered oil that is hazardous because it exhibits the characteristic of ignitability or exhibits the toxicity characteristic for benzene (or both) is eligible for the exclusion. 

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