| Biodegradable wastes | Non-biodegradable wastes | |
| i. | These are wastes which can be broken down to harmless or non-poisonous substances by the action of microorganisms. | These are wastes which cannot be broken down to harmless or nonpoisonous substances by the action of micro-organisms. |
| ii. | These wastes undergo rotting. | These wastes do not undergo rotting or take a very long time for rotting. |
| iii. | Example: domestic sewage, newspapers and vegetable matter. | Example: polythene bags, plastics, glass, aluminium cans, iron nails and DDT. |
