Preservative free cosmetics: are we talking about the daisy flower or my dear friend Daisy?

I have recently attended a lecture by Professor Michael Cork entitled "Killer Cosmetics - from bacterial contamination to skin barrier breakdown", kindly organized by the Society of Cosmetic Scientists in the UK.

Professor Cork is head of the academic unit of dermatology research at the Sheffield university and has worked on severe cases of infants skin rashes caused by microbiologically contaminated skin products. He also explained in a visual and clear way the key mechanism behind the skin barrier.

However I feel I ought to comment on one of the major messages of his lecture: preservative free cosmetics are dangerous whereas products preserved with parabens are very safe.

I approached Michael after his talk to inform him that there are several products on the market which are microbiologically safe and yet preservative free, and his answer was very much based on the chemical function of preservative (the daisy flower) rather than the marketing definition of preservative free (Daisy my friend). They are called the same thing but actually they are different. Let me explain to you.

The chemical function of a preservative is essentially to kill bugs, so if you mean that (daisy the flower) and you say preservative free cosmetics you actually mean a product with no antimicrobial protection whatsoever.  There are 2 types of products that fall into this category: oil based ones (no water) and water based ones with really no antimicrobial agent (it is very rare to come across this worst case scenario. Professor Michael was mentioning contaminated products from Libia and Iran).

Then there is my dear friend Daisy: the legal definition of a cosmetic preservative which comes from what is listed on Annex VI. If a cosmetic ingredient is listed on this annex it is called officially a preservative. This means that you can have a cosmetic ingredient which is not listed on this Annex and still act as a preservative (daisy the flower). And if you use this ingredient to protect your cosmetic from the bugs attack you can claim it to be preservative free and still provide to the public a safe product (providing it has passed the relevant tests required by law).

This is a great example of the gap between some scientific definitions and legal definitions, where you can use the same label or name meaning two different things depending on the point of view. And this gap can be used in a misleading way to reinforce a message or it can cause confusion in people not aware of it. Professor Michael was also stressing the need for education, on which I agree totally, however how it can be done is still a mystery to me (if you have suggestions please tell me).

In my opinion the essence is to ensure that the preservative free cosmetics you buy have been manufactured by a reputable company that complies with the law and makes sure that it is microbiologically safe.

Comments

[Barbara Olioso]

Dear Susan

thank you for your contribution! Oh my lord, it is a dangerous practise to release products on the American market with bugs or too many preservatives as they can cause skin reactions.
Don't they do a challenge test then and a safety assessment? and what happens to people when they apply products with a lot of preservative in them?

[Susan Sawhill Apito]

First I'd like to say how thrilled I am to find this website!

Dr. Barbara, you state "you can have a cosmetic ingredient which is not listed on this Annex and still act as a preservative (daisy the flower). And if you use this ingredient to protect your cosmetic from the bugs attack you can claim it to be preservative free and still provide to the public a safe product (providing it has passed the relevant tests required by law)."

This is my understanding as well, because while an ingredient (daisy or essential oil of daisy) might act as a preservative - or for that matter might act as a fragrance - US labeling laws are based on what is is...not what it does.

You mention "providing it has passed the relevant tests required by law", which is where US laws fall short: there are no tests required by law in the USA. NONE.

So formulators and "home crafters" are finding recipes online, making up a batch of lotion, and selling it on ETSY the next day. Not testing for microbial contamination, and certainly not testing to determine the minimum level of preservation necessary to formulate a safe product. No. Instead they add the MOST of whatever preservative or ingredient they hope will preserve their product.

[Barbara Olioso]

Dear Dene
you are keeping me busy with all this blogging!
As a chemist myself I do not want to feed the mantra chemicals=poison, and that is why I quoted in brackets the term chemical in my previous reply. It is very challenging to explain to people without a scientific background that plant extracts contain chemicals because the immediate reaction would be oh my God. So my position is not to feed it by choosing carefully the wording on my literature and articles, still believing "natural chemicals" are best for the skin (and I say this with the awareness that not all naturals are good for us).
Ok I refreshed myself on Annex 6 and it is about the official intention you use an ingredient for, so if you had an essential oil with antimicrobial activity you can declare it as fragrance,or if you had an herbal extract you can declare it as moisturising. I know you will not like this, however that is the way it is done.. So I take your point on the legal definition of preservative, however there is a legal gap in the Directive that allows the preservative free claim...
Good to know the skin esterase is not present in rabbit skin however I am still concerned about the parabens absorption for 2 reasons:
1- they were found in urine as you know. If they get totally hydrolysed how did they end up in there?
2- there are 2 papers questioning the esterase efficacy in the skin. For example Ishiwataru et al 2007, reported menthylparaben being accumulated in the stratum corneum in human volunteers. The methylparaben cream application went on for 4 weeks and the methylparaben content went down 2 days after stopping the application. There are also 2 more articles by Prusakiewicz et al 2006 and Harville et al 2007 showing that the esterases activity in human skin is slower than rats..
You probably know most of the articles on parabens, on the basis of that, is there consistent data about what happens to the parabens once they are absorbed? because they do get absorbed...And what happens when they accumulate in the stratum corneum?
I have not changed the statement, I have always referred it to the parabens, not a generic statement, I am a scientist..

[Dene Godfrey]

Dear Barbara,

I will try to summarise very briefly:

The perception of the public (regarding "chemicals") is a misperception, which is encouraged by, amongst others, those who post blogs such as this. I make this comment based on your statement that your perception is more in line with that of the public than mine. I repeat - there is no legal definition of a preservative within the Cosmetics Directive. There is a definition, however, within the Biocidal Products Directive, and that would bring most of the cosmetic "non-preservatives" within its scope if the BPD also applied to cosmetics.

Moving swiftly on to the "60%" figure, there is an important point here.

According to your source (Pedersen), 60% of methylparaben is absorbed by the skin when applied in a cosmetic. I take issue with that study making the claim that excised rabbit skin is a useful model to mimic human skin. Parabens have been showed to be easily degraded by esterases in the skin (and in the blood), and excised rabbit skin will have no esterase activity as this ceases very soon after the demise of the animal. Therefore, both your statement and that of Pedersen et al are highly disputable, in terms of the reality of living human skin, particularly as a much more recent and more in-depth study (as yet unpublished) has claimed that parabens are barely absorbed through the skin - and this was an in vivo study and, therefore, significantly more relevant than Pedersen's in vitro study.

If I recall correctly, your original statement said that 60% of cosmetic products are absorbed, but I am prepared to have misremembered this, or have you amended it?

[Barbara]

Dear Dene
thank you for your rich contribution, I shall reply in a few points to make it easier:
1) I believe there is a discrepancy between the legal and scientific definition, in the sense that there is a loop hole in the Cosmetics directive that allows it. You can still get a "preservative free" product to pass all the relevant tests to comply with the law in a safe way. There is also the public perception about preservatives being "chemical" (synthetic) by associating them with something unsafe or nasty. This is an additional gap in the interpretation of "preservative free" claim. For the general public preservative free is chemicals free and not bugs free. For me it means bugs free and without preservatives on Annex VI, for you it is bugs free and free from any bactericidal type of ingredient. There is freedom of interpretation, you are entitled to your stand and I am entitled to mine which is more in line with the public perception in the sense of "chemicals" free. However we both agree that bugs are bad news and that a product should be able to cope with them.
2- the article Professor Cork quoted is based on preservative free creams with no real preservative (natural or synthetic) in them, so in my view it is misleading to quote that to put down preservatives free cosmetics all together, rather than specifying it is more a question of"bugs rich" creams. That is the essence of the real message and that would really empower people to choose the safe products rather than running away from preservative free cosmetics which passed all the relevant tests and are safe to use.
3- the reference of the parabens absorption is:
In vitro skin permeation and retention of parabens from cosmetic formulations
Auteur(s) / Author(s)
PEDERSEN S. (1) ; MARRA F. (1) ; NICOLI S. (1) ; SANTI P. (1) ;
Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)
(1) Dipartimento Farmaceutico. University of Parma, Parco Area delle Scienze, 43100 Parma, ITALIE
Résumé / Abstract
Parabens are antimicrobial agents widely used in foods, cosmetics and pharmaceutical products. Although non-mutagenic, non-teratogenic and non-carcinogenic, parabens can induce allergic contact dermatitis and posses estrogenic activity. The aim of this work was to assess the skin permeation and retention of methyl- (MP), ethyl- (EP) and propyl- (PP) paraben from three commercial cosmetic creams. The results obtained indicate that parabens are capable of permeating through and accumulating in the skin. The extent of penetration depends more on paraben characteristics (solubility, lipophilicity) than on the composition of the formulation. In particular, the percentage permeated across the skin was independent of the composition of the cream used and decreased in the order MP, EP and PP, in accordance with decreasing solubility. After 8 h of contact with the skin, 60% of MP, 40% of EP and 20% of PP were found across the skin. Concerning skin retention, the percentage remaining in the skin after 8 h depends on both paraben characteristics and on the composition of the formulation used. In conclusion, it appears that only the type of paraben, in particular its water solubility, affects skin penetration whereas the composition of the emulsion, which influences skin retention, plays a secondary role. Finally, excised rabbit ear skin can be considered as a good model for human skin for in vitro experiments.

[Dene Godfrey]

I have made this a seperate comment because, although it is related to Prof. Cork's lecture, it is an entirely different subject! Prof. Cork twice mentioned the statement about 60% of cosmetics being absorbed by the skin and, like me, disagreed with this claim (for several reasons which I will not elaborate on here). I note that you use this statement in the products section of your web site but, unlike every other time I have seen it, you actually make some mention of the origin of this claim. I would be very grateful if you could provide me with the actual literature reference so I can check this for myself because, unlikely though it may seem, if this is based on good, sound science, I will amend any future comments I make on this topic.

[Dene Godfrey]

Dear Barbara,

As you are well aware, I was the Chair of the session you describe, in my capacity as President of the SCS and, whilst I am sure that Professor Cork is well able to respond on his own behalf, I feel that I should add my own comments to your observations.

Professor Cork was correct in his assertion that unpreserved products are dangerous. He only specifically mentioned parabens once (and they ARE safe to use as preservatives), but he was not suggesting that they are the only option. It is disingenuous to imply that, because the product he specified was from the Middel East, there is not a problem elsewhere. He has (as yet unpublished) data on "preservative-free" products available in the UK which demonstrate clear failures in the standard microbial challenge test - which mean that they are potentially harmful to the consumer.

It is also disingenuous to suggest that "alternative" preservatives are any more safe than synthetic ones. If the animicrobial substance (of whatever origin) is mild, then a higher concentration is required to be effective, compared with a less mild preservative - this broadly balances out the subsequent risk in the final formulation. The use of the term "preservative free" is misleading in most cases. (I am not referring here to the substances that are used to reduce water activity, as they are not antimicrobial in their own right.)If the product contains any of the antimicrobial ingredients that are not "official" preservatives, then the product is not "preservative free" - a preservation system is still in place. If you are adding an ingredient in the full knowledge that it is being added because it acts as a preservative, I think you should ask yourself if it is being totally honest. Using the legal definition of preservative is no defence as, strictly speaking, there is no "legal definition" of a preservative. Annex VI of the Cosmetics Directive only lists permitted preservatives, it does NOT define what constitutes a preservative, and this is an exremely important distinction.

I contend, therefore, that any claim to be preservative free is unacceptable (and totally uneccesary) on two counts. Firstly, because if the product contains any antimicrobial substance (whether as a primary or secondary function), then it contains a preservative and, secondly, if the product genuinely does not require preserving by ANY means, then the claim is redundant (and there are legal implications of making ANY "free from" claims in an increasing number of countries, especially redundant ones as I have described).

The use of the term "preservative free" implies that preservatives are not safe. The reason Annex VI exists is to ensure that only safe preservatives are used in cosmetics. Encouraging the use of "unofficial" preservatives that have not undergone the same highly rigorous risk assessment as "official" preservatives may be argued to be a step backwards in terms of consumer safety. Before anyone accuses me of having a vested interest in "offical" preservatives, my company also offers alternatives, but I make it clear to the potential customer that they should use with caution, and advise strongly against making "preservative free" claims. The use of "unofficial" preservatives (as a primary function) is illegal in the EU.