100% biodegradable: fact or fiction?

We often read detergents labels that show the claim “100% biodegradable” to corroborate the concept that those products are very ecological. Why Bensos’ products don’t do it? As a matter of fact, this claim is only a publicity stunt, it does not refer to any regulations about parameters to be measured with laboratory analysis.

Biodegradabilità is the tendency of chemicals to be degraded – that is broken to many little pieces, which will harm neither Nature nor human beings anymore – by biodegradator microorganisms (saprofite bacteria) naturally living in the environment. Most restrictive investigations, showing the higher biodegradation degree for a chemical, cannot give “100%” as a result, but rather “at least 60%“; a very important thing is that the time must be limited (maximum 28 days) in order to avoid that persistent chemicals go on to pollute the environment for a long time.

In addition, in Chemistry it makes little sense speaking of “100%”, as speaking of “zero”: an instrument cannot guarantee the total presence – or the total absence – of something, because any method, however precise the analisys is, will always suffer from a little error margin. Therefore, a trustworthy chemical claim can say neither “zero” nor “100%”, at most a value within a range (as “greater than”, “smaller than”…).

In closing, biodegradation most restrictive analisys (OECD 301 Test) usually are made on single chemicals, not on finished products (that are heterogenoeus mixtures of many chemicals). Regulation recommends not to apply that kind of methods on complex mixtures, because most of them would not pass the examination: each chemical alone could be degraded rapidly, but altogether could react with each other in unknown ways and show then no tendency to degrade quickly.

Studying in experimental cooperation with University of Brescia, as a precaution Bensos preferred to make such tests on its own formulations, even if they are made of complex mixtures: tests allowed us to know that some formulations must not be produced, as they’re persistent and may be harmful for the environment! Bensos’ choice is to make a reliable and accurate communication about chemicals properties, not build on stunts or fakes, but rather on verifiable and documented technical data.