Here's why:

* Biodegradable substances are materials that can be broken down by microorganisms (like bacteria and fungi) into simpler substances, such as carbon dioxide, water, and inorganic compounds. This process occurs naturally and doesn't leave harmful residues behind.

* Organic waste refers to materials derived from living organisms, such as food scraps, yard waste, and animal manure.

Therefore, biodegradable organic waste is not harmful to the environment when decomposed.