The following are the major sources of hazardous wastes;
1. Petro chemical industries: phenols, acids, caustic and organic compounds
2. Metal industries: heavy metals, fluorides, cyanide, acids, alkali, solvents and phenols
3. Leather industries: heavy metals and sulfides
Others that generate partial hazardous waste: rubber, batteries, pharmaceutical, textiles, dyeing and finishing, leather tanning and finishing, special machinery, plastics etc.
Read Also : Characteristics of Hazardous Wastes
Classification of Hazardous Waste
1. EPA classifications
a. Hazardous waste from non-specific sources: – these are generic waste commonly produced by manufacturing and industrial processes e.g. halogenated solvent used in degreasing.
Examples include tetrachloroethylene, methylene chloride, 1,1,1-trichloroethane, carbon tetrachloride, chlorinated fluorocarbons etc.
b) Hazardous waste from specific sources: – these wastes are produced by specific industrial processes such as wood preserving (such as creosote and pentachlorophenol), petroleum refining (e.g. Dissolved air floatation (DAF)), and organic chemical manufacturing (distillation bottoms from production of acetaldehyde from ethylene). Others include inorganic chemicals.
c) Commercial chemical products:-this consists of specific commercial products like chloroform, creosote, acids, pesticides etc.
d) Hazardous constituents:– these are hazardous constituent capable of producing toxic, carcinogenic, mutagenic, or teratogenic effect on human and other lives e.g. tetrachloroehylene, methylene chloride trichloroethylene, 1,1,1-trichloroethane etc.
2. Industrial classifications
The hazardous waste management industries recognizes five categories of waste
- Metal/metal finishing
2a) Classification based on quantity produced
a) Small quantity generators (SQG): – if the total quantity of the hazardous waste produced is <100 kg/month of none acutely hazardous waste or < 1 kg of acutely hazardous waste.
b) Medium quantity generators(MQG): – if the total quantity of the hazardous waste produced is between 100-1000 kg/month of none acutely hazardous waste.
c) Large quantity generators (LQG): – if the total quantity of the hazardous waste produced is between 1000 kg/month or more of none acutely hazardous waste and > 1 kg/month of acutely hazardous waste.