| Degradable substances | Non-degradable substances |
| 1. The substances which can be naturally reduced into their inorganic constituents are called degradable substances. | 1. The substances that cannot be degraded on their own into their inorganic constituents are called nondegradable substances. |
| 2. Degradable substances are not accumulated in the nature. | 2. Non-degradable substances remain accumulated in the nature for a long time. |
| 3. Degradable substances emit foul odour when they are being decomposed. | 3. Non-degradable substances may not emit foul odour as they are not degraded. But they make the place look dirty. |
4. Usually microorganisms play a part in the degradation process, hence such substances are also called biodegradable.
E.g. Vegetables, fruits, wood, cotton or wool fibres, etc. | 4. Microorganisms cannot act on nondegradable substances and hence they are also called nonbiodegradable substances.
E.g. Plastic, thermocol, glass, metals, etc. |
