Biodegradation of surfactants

To promote sustainability, manufacturers work hard to reduce the environmental impact of their products. One way to do this is to favour the use of ingredients that are biodegradable.

Biodegradation is the natural way organic materials  are broken down by bacteria*. Bacteria are found in abundance in sewage treatment works, soil and waterways and they grow by breaking down chemicals into smaller compounds, nutrients and water. Since many detergent ingredients are made up mostly of carbon atoms (i.e. they are organic materials), bacteria may be able to convert that ingredient into CO2, water and nutrients. When this occurs, the ingredient does not pose a risk to the environment because CO2, water and nutrients are safe.

There are two common forms of biodegradation: aerobic which occurs in presence of air and anaerobic which occurs in its absence. The breakdown products of aerobic biodegradation are carbon dioxide, water and mineral salts whilst the anaerobic process is less efficient but also less abundant and can results in the generation of methane or other small hydrocarbons.

Ultimate biodegradation means the level of biodegradation achieved when the component is totally used by micro-organisms in the presence of oxygen resulting in its complete breakdown to carbon dioxide, water and mineral salts.

Primary biodegradation is mostly considered in the context of surfactants, which are the main washing actives of a detergent. It is called ‘primary’ since it is the first step in the biodegradation process of these washing actives. This initial biodegradation step will results in the loss of the surface-active properties, which simultaneously eliminates the toxicity of the wash active.

Since the late 1970s, regulations have required that manufacturers prove the primary degradation of anionic and non-ionic surfactants. At present, the vast majority of surfactants used in detergents – including cationic and amphoteric surfactants –fulfill even more stringent requirements regarding their ultimate biodegradation.

The introduction of the EU Detergents Regulation (EC) 648/2004 in October 2005 made the proof of ultimate biodegradation obligatory throughout the EU for all groups of surfactants used in domestic detergents. In order to know more about biodegradability please click here.

* In cleaners and detergents many organic components are used, next to surfactants also f.i enzymes and perfume are organic components.