Solid wastes are unwanted or discarded materials. They may contain dust, ash, paper, packing's and also profitable matters such as fruits and vegetables. They may be the products from houses or from industrial, commercial and agricultural operations. They are called as litter in country side and refuse in cities.
Industries in India, like industries anywhere else in the world generate a variety of wastes in large quantities. These wastes may be solid, liquid or gaseous. Industry-wise quantities are not accurately known in many cases.
Hazardous wastes are chemical by-products of an industry, a factory or a chemical plant. They may result from household activities or even from a hospital or a research laboratory.