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.
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.
I think this is a universal truth, but it is certainly true in labs. The most stressful role is middle management. I enjoyed my time as a bench chemist doing the actual work. I enjoy supervising projects at a higher level. But most of my bad memories of my career are when I was in between – managing a team but reporting to senior management. Continue reading →
There is an article I have seen posted on Facebook a couple of times that highlights the health risks of synthetic fragrance ingredients. I won’t link to it, but if I am seeing it there is a good chance you will have seen it too. The thesis it proposes is that synthetic chemicals in fragrances are toxic and might be dangerous to people who inhale them in public places, even if they aren’t actually wearing the fragrance themselves. Continue reading →
Silver can help make you beautiful as well as be used in jewellery
I don’t think that animal testing works the way some people commentating on the internet appear to think it works. This was brought home to me when I was asked a question about a new preservative material called silver citrate. It is one that might appeal to the lovers of natural because both silver and citrate sound safe and natural. We all know what silver is and so assume it is safe. Citric acid sounds like it comes from oranges so that sounds pretty safe too. But the person who was interested in it had read the material safety data sheet that came with it, and concluded that it had been tested on animals. For them this was a no no. Continue reading →
Preservatives in cosmetic products are a problem and will remain so until the way they are made and used changes significantly. I imagine someone somewhere is working on a project to create cosmetics in a small machine which you can programme with your favourite recipes. That would enable people to choose their own preservative option or to not use them at all and just make their personal care products fresh as needed. But until that technology becomes widespread preservatives are a necessity, and some people will have allergic reactions to them. Even the ones with a low propensity to cause allergic reactions, like the parabens and methylisothiazolinone, still cause plenty of people issues.? Continue reading →
There’s a new paper out with some numbers from dermatology clinics about reactions to methylisothiazolinone (MI). Dermatologists regularly patch test people to discover what they are allergic to. This involves applying a set of common materials that tend to provoke allergic reactions to the skin, and seeing which ones the individual reacts to. Continue reading →
Among the many things I try to cram into my schedule is a newsletter for people with sensitive skin. I am not very successful at doing this I am afraid, and I don’t get the newsletters out very frequently. But despite this I get a steady stream of people talking to me about their issues with reactions to cosmetics. In particular, to preservatives. And particularly in particular to methylisothiazolinone. Continue reading →
There are an interesting couple of points in the comments thread on my blog post asking for MI not to become a scare story, from Suzanne. She has drawn my attention to a paper from 2012 that details developmental problems in tadpoles exposed to MI. She concludes from this that MI is potentially unsafe for humans as well and asks what the liability is for companies that continue to use it now that this risk has been identified. Continue reading →
I have a very very expensive formulation of a serum here. Would you please be so kind to evaluate it? My questions are especially concerning preservatives.. and also: does skin benefit from so many different ingredients and antioxidants…? I think I think that simple is best. The formulation might be of interest to you, as it seems at the forefront.
There is a news story that L’Oréal have issued a product recall for their Ideal Moisture Dry and Sensitive Day Cream in Canada. The reason is that the level of MI in it is higher than Health Canada’s regulations allow. This is quite a rare event – big cosmetic companies are usually pretty good at following regulations. Unfortunately Google has not revealed the details of just how much over they were. But the product has been on the market for three years so there is a good chance that they have simply failed to keep up with the regulations and that the product was legal when formulated and launched. They have shifted just under 60,000 units. Continue reading →