Biodegradation can be described as the process in which bacteria (naturally occurring) break down or degrade chemicals and substances into inert substances. In a basic way, the bacteria produce enzymes that target a specific chemical bond within the molecule, breaking that bond and allowing further chemical reactions to occur, ultimately leading to the production of inert substances. This process occurs quite naturally without any intervention on our part, e.g. oil spills in the ocean promote the rapid growth of naturally occurringOceanospirillalesbacteria which breakdown crude oil, before returning to a dormant state. There are broadly two variations of biodegradation: Aerobic and anaerobic. Simply, the difference between the two is aerobic biodegradation is the breakdown of substances in the presence of oxygen, whereas anaerobic biodegradation is done in the absence of oxygen.

How does this apply to cleaning products? All waste detergents and cleaning products eventually end up in the drains, and with annual consumption, commercial and domestic detergents combined, amounting to millions of litres, the fate of that waste is of great importance. Biodegradability is beginning to be of serious concern and increasing importance with theintroductionof all detergent ingredients into current regulation (see later details on regulation in Section 3). This has lead to extensive reformulations over the years after a number (and increasing number) of detergent ingredients have been banned or severely restricted. New and quite innovative ingredients have taken their place, ingredients like sugar-based surfactants that completely breakdown naturally in the environment within 10-20 days, new builders that replace the old phosphate-based ones. The main requirement now for biodegradability is for a surfactant ingredient to be 60% mineralized to water, carbon dioxide and mineral salts within 28 days in aerobic sludges. This should be shown on the MSDS sheets upon purchase of the detergent as biodegradability is a selling point for most detergent suppliers, then this point should be borne in mind for the future.