ABSTRACT
This chapter presents the means by which chemical waste itself can be classified into various sub-groups. Thus, there is hazardous waste and nonhazardous waste. There are three basic approaches to defining whether or not a chemical waste is hazardous: a qualitative description of the waste by origin, by type, and by constituents; classification by characteristics based upon testing procedures; and classification as a result of the concentration of specific chemical substances. A chemical waste is considered hazardous if it exhibits any one or more of the following characteristics: ignitability, corrosivity, reactivity, and toxicity. The primary environmental concern regarding chemical wastes in the geosphere is the possible contamination of groundwater aquifers by waste leachates and leakage from wastes. In summary, many specific chemicals in widespread use are hazardous because of their chemical reactivities, fire hazards, toxicities, and other properties. A waste that is classed as nonhazardous can, depending upon the circumstances, be classed as hazardous.
