Sales of natural cosmetic products are on the rise but the market is still dominated by products formulated with a high proportion of synthetic chemical ingredients. Take a look at shampoos and hair conditioners which usually contain chemicals and although the amount used may be small, I often think about the sheer volume used nationally on a daily basis and the potential impact on our natural environment. So it is always good news to hear of new developments of more environmentally friendly cosmetic ingredients. I welcome the use of ingredients that are biodegradable and have low aquatic toxicity.
Have you used a hair conditioner and wondered how it makes your hair feel so soft and smooth? Well it’s most likely due to the hair conditioning agents called cationic surfactants (also known as quaternary ammonium compounds). These chemicals are the most common ingredients in hair conditioners. Basically their ability to condition hair is all down to the special properties of their molecules which have a hydrophobic (water-repelling) part and a positive (cationic) charged part. The positive head is attracted to the negatively charged hair protein and this interaction makes it easier to comb the hair as well as managing static build up so fly-away is largely reduced. Examples of cationic surfactants are: cetrimonium chloride, behentrimonium chloride and stearamidopropyl dimethylamine.
I have noticed that cetrimonium chloride and behentrimonium chloride are very popular and widely used in hair conditioning products.
Generally a large proportion of surfactants are degraded in wastewater treatment plants but some amount does still end up in surface waters, soil or sediment.
However, cetrimonium chloride and behentrimonium chloride have poor biodegradability and are considered to be very toxic to aquatic life with long lasting effects. Apparently they adsorb strongly to soil and sediments and their microbial degradation is minimal in absence of oxygen. In contrast stearamidopropyl dimethylamine is readily biodegradable but it also shows high aquatic toxicity.
Behenamidopropyl dimethylamine is a new surfactant similar to stearamidopropyl dimethylamine but with low aquatic toxicity. I did check out the hair care aisles at my local Boots and Superdrug stores and could only find one brand of hair conditioners that is currently using behenamidopropyl dimethylamine. John Frieda seems to be the only brand available locally with this eco-friendly surfactant. This new biodegradable chemical converts into a cationic surfactant in acidic condition and its conditioning effect is reported to be superior to that of commonly used cationic surfactants. This proves that it is possible to create environmentally friendly chemicals without compromising on hair conditioning performance. In future, it would be great to see more sustainable natural ingredients in cosmetics but where this isn't feasible then a switch to eco-friendly chemicals.Last modified on