Sodium Benzoate

Sodium benzoate
Styrax – the shrub from which benzoic acid can be extracted

Sodium benzoate is a preservative that crops up on ingredient lists for skin care products.  It is safe, works well enough and doesn’t give rise to many skin reactions.

I don’t think it is many formulators favourite though, because there are other preservatives that work better. Not every preservative works in every formulation and against every organism, and sodium benzoate is one that really needs a low pH to work well and even then isn’t enormously effective against all the microbes you’d like it to be.  So it has its uses, but it isn’t especially versatile.

Crystals of Pure Benzoic Acid

To a chemist though, the name is quite interesting.  It is the salt of benzoic acid, and benzoic acid has played a key part in the development of organic chemistry.  It was first derived from an asian shrub.  Specifically, it was extracted the gum of the Styrax platanifolius.  This had been used for centuries but was purified still further by a sixteenth century French chemist.  He got it into a crystalline format from which he concluded, correctly, that it must therefore be a single compound.  I think that this was the first pure natural compound to be identified.  

The chemist’s name was Nostradamus.  He’s still famous, not for his science but for some confusing predictions he made that continue to be talked about.

The chemistry of this compound was the focus of intense interest in the nineteenth century.  It was studied by many chemists. But the prize for working out its structure was taken by Friedrich Wöhler and Justus von Liebig.  These are two of the giants in the history of chemistry.  Their work was later built on to create the discipline of organic chemistry.  

There are quite a lot of cosmetic ingredients that are derivatives of benzoic acid, so you see ‘benz’ quite often on the backs of packs.  It is a neat little history lesson.

Everything You Need To Create Your Own Skincare Range at CCC

3 thoughts on “Sodium Benzoate

  1. Jacqui

    Thank you. Wondering if u know ingredients to Diego Dalla Palma lipstick? I just had a reaction and was either Tesco washing up liquid or this!?

  2. Colin Post author

    Anyone can develop an allergy to anything at any time, so there is no way to know for sure without a patch test. But I’d say the washing up liquid was more likely.

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