A hazardous waste is any waste or combination of wastes that poses a substantial danger, now or in the future, to human, plant or animal life and which therefore cannot be handled or disposed of without special precautions.

The Hazards and Disasters can be classified into four categories viz., Natural events, Technological events, Man-made events and Region-wise events. The adverse impacts caused due to the indiscriminate disposal of Hazardous Wastes (HWs) come under the category of Environmental Disasters.

CLASSIFICATION OF HAZARDOUS WASTE

US EPA has designated five categories considered as hazardous:

1. Specific type of wastes from nonspecific sources:

a. halogenated &non-halogenated solvents b. electro-plating sludges

c. cyanide solutions from plating batches

2. Specific types of wastes from specific sources;

a. oven residue from production of chrome oxide green segments

b. brine purification muds from the mercury cell process in chlorine production

3. Specific substances identified as acute hazardous waste:

a. potassium silver cyanide, b. toxaphene

c. arsenic oxide.

4. Specific substances identified as hazardous wastes e.g. Xylene, DDT, carbon tetrachloride

5. Characteristic wastes:

Wastes not specifically identified elsewhere exhibiting properties of:

ignitability, corrosivity, reactivity, or toxicity