Q: Is there a perfect preservative, either natural or synthetic, for cosmetics and personal care products?

A: No.

Is this an unsatisfactory, disappointing, unacceptable, infuriating answer? In this day and age, can’t we do better? Oh, we are always doing better – today better than yesterday, tomorrow will be surely better than today, but ‘perfect preservative’ sounds like contradiction in terms: a hero and a villain, all in one?

In order to understand preservatives more clearly, and the expectations placed on them, a journey down a rabbit hole may be necessary. But – how far down that rabbit hole do we want to go? There are no simple answers (other than the one above), instead, there is a lot to learn, which may not provide a satisfying answer anywhere along the journey. The rabbit-hole metaphor is perfect for our times, and it has to do with a simple premise many of us face every day – how much do we really want to know about certain things?

Let’s find out.

In my previous article ‘Tempest In a Jar’ I explained, among other things, why the need for preservation in skin care products. I will go over it again briefly: Bacteria and molds thrive on water, which is the major component of all creams. There are other nutrients in face creams that they like as well, but without water there is no life, not for us and not for micro-organisms either. If there were no preservatives in cosmetics, microbes would proliferate at tremendous acceleration (slowed down somewhat if the product is refrigerated) and sooner rather than later, in fact very soon, the product will go bad. Which means that using it would pose a health risk to a person’s skin. A product without any preservatives has a short shelf life, which can be estimated at around a week, or two, this period varying slightly. While there are microbes all around us, even inside our bodies, some of them are classified as pathogens, which means that they can turn nasty if given a chance.

If you prepare your own masks and potions at home for your own use, from ingredients in your kitchen pantry or a few you have purchased from your health food store, you definitely don’t need preservatives. You’ve made a small batch for a few days, you keep it in the fridge and there is nothing to worry about. However, if you give some of that product to your friend, or even sell it to her, and then word gets around and she takes some for a friend of a friend and so on, you will come up against some very tall obstacles: you may repeat it until you are blue, or even write it on your hand-made label that the product will go bad in three days, but the chances are that somebody will forget the instructions, forget to even use the product, never put it in the fridge, a child may open it and like the yuck inside enough to do with it who knows what, and soon enough the mess outside of the jar will be far greater than the one inside. It is, or it should be, a basic credo of any manufacturer to make the best possible product that is safe to use.

And here we come across the word that is pivotal in the chess-game played at the bottom of this particular hole: ‘safe’.

The sticky issue with preservatives is their safety. They can’t be safe for microorganisms, because then they are useless. They must be safe for humans, otherwise they are toxic. The product without preservatives is not safe to use. The product with preservatives may be safe to use, in terms of being germ-free, but it might be toxic if the preservatives used aren’t safe, or are used in too high a concentration, or…

In order to alleviate the confusion that has already been stirred, I will proceed with the article by dividing it into two sections:
1. Review of preservatives and their place in today’s world
2. Focus on natural preservatives.

Us & Them

The hypothetical situation above involving you making your own potion and then selling it to your friend had another purpose than the mere illustration of things getting messy quickly without preservatives. The intent behind it was to put you in a position where you will feel the responsibility for what you have created. Most people would feel like you – they don’t want things that they are creating, or handling, to do harm to other people.

Cosmetic chemists, who formulate skin care products, are not any different in that. They will never consciously choose to create a product that is unsafe to use. That would go against not only ethical standards of a profession and an individual, but also against the law. On the other hand, nobody, including chemists, feels like reinventing the wheel every day. People, in general, tend to stick to the tested-and-true principle, and that applies to chemists as well. Who is to blame them? If the product they create is used by people, the company they work for invests millions of dollars in production, distribution and marketing of the product, nobody really wants to see something go wrong, and so they stick to things that work reliably well.

Cosmetic industry owes its very existence to the advent of preservatives. Preservatives first found their way into food, and shortly after into personal care products. That occurred at the beginning of the 20th century. At the time when preservatives were a novelty, the knowledge of human physiology was not what it is today either, which is not to say that today we know everything. We only know more, and that still has as many deep pitfalls gaping open, as there are those successfully filled. The body of knowledge in every field has expanded at a mind-blowing speed during the 20th century. Technology followed, and then the Government. As a result, many regulatory agencies have been established to control the industries and protect the interests of the public. Over the years and the decades that followed since the introduction of preservatives, some of them have risen and fallen, and some of them have stayed. Preservatives in use today have been tested extensively. Under the guidance of toxicologists and Government officials every country established its list of acceptable preservatives for personal care products, and their levels of use. This last entry – the level of use – is crucial, because, as you remember, the preservative has to walk a thin line between being effective against microorganisms and not being toxic to humans.

There is an important note to insert here: Government agencies don’t consider a preservative any compound, natural or synthetic, that is not on their official list. What that means is: if a formulator uses other chemicals to preserve the skin cream, which are officially not recognized to be preservatives, then sometimes marketing claims are being made, such as ‘preservative-free’. This is untrue in the real sense, since we now know that a product has to be preserved, and there is something in the product doing the job of the preservative, with or without the title.

The following are most commonly used preservatives in cosmetics today:

Parabens (Methyl, Propyl, Butyl, Ethyl)

Imidalozolidinyl Urea


DMDM Hydantoin

Diazolidinyl Urea




Although compounds listed above are all synthetic chemicals, there are some natural chemicals that have been used, and are recognized as preservatives as well (such as organic acids, for instance). Each of these preservatives has been around long enough for the chemists to gain confidence in what they are doing.

Does it sound strange to read about a question of confidence in chemists, especially when it comes to preserving their formulations? If it does, then we have to make an important clarification: the issue of preservatives is not only difficult enough from the standpoint of how safe they are for humans, but the very job they are supposed to perform is always in question. One of the least known facts about cosmetic products is that they are very difficult to preserve both effectively and safely. The standard combinations in the mainstream industry have been acquired after many years and decades of failed attempts, and they are still not foolproof. Why is that so? Because there is no perfect preservative. (If one ever came along chemists are likely to be much more excited about it than the public.)

Factors that influence how effective a preservative is going to be are many:

Content of water in a product

The conditions under which it is manufactured, i.e. cleanliness and hygiene of the premises

The phases and steps of the manufacturing process itself

pH value of the product

The condition and purity of the ingredients that go into the product

The type of ingredients used (some of them inactivate or reduce the efficacy of preservatives)

The packaging of the product, i.e. how much of it is exposed to air through everyday use

The way the product will be used; and so on.

Any change in any of the factors mentioned above, and the whole process goes back to the very beginning.

Are the formulators fighting against a phalange?

There are several types of bacteria, fungi, molds and yeasts that thrive in skin care products, and preservatives are limited in their effectiveness against them. Typically, the ones that have effect on bacteria don’t have it on molds, and vice versa. Furthermore, ones that are effective against gram-positive bacteria are sometimes not effective against gram-negative. The obvious answer, and necessity, is to combine the preservatives so that their actions keep the product safe from microbes. Fighting against several totally different species of microorganisms, combining few different chemical compounds to win that battle, all in the medium that supports the growth of microbes and then add packaging that is at times ridiculous from a standpoint of actually successfully completing the task at hand… and you can see how preserving a cosmetic product can be a nightmare.

Consider, for example, a sponge applicator in make-up. You may or may not like it, maybe you even love it. From a formulator’s standpoint, a little sponge poses a big challenge. If used for dry powders, like eyeshadows, the concern is minimal. But, if used for anything creamy and moist, the sponge becomes a cavernous maze, infinitely larger that its neat little tip, where countless microbes can create safe havens from preservatives, which can’t get to them. Since there are many products with sponge applicators, formulators have obviously found the way to present the market with the safe product, but just by introducing a new style of packaging the effort to preserve properly was brought to a completely new level.

Let’s review ‘safe’ again. Preservatives, whether synthetic or natural, are chemicals that disrupt the life cycle of microorganisms, and thus eliminate them from the product. To microbes, they are poisons. This cellular toxicity is not limited to microbes – preservatives are, more often than not, toxic to higher organisms as well, including humans. How toxic? Well, that is where all this trouble festers. Toxicity of preservatives is directly connected to the quantity that is used. If little that is needed to kill the microbes is not causing any known damage that has been proven scientifically as such (scientifically meaning through rigorous testing and study of as many factors possible), then they are considered safe. If some danger and increased risks are uncovered and proven later on, then they are considered not safe any more. If this sounds like a brutal method of accumulating knowledge through trial and error, consider that most if not all knowledge of humankind has been accumulated that way. Most chemists follow that route, some look for alternatives right from the start. I don’t think that it can be said about either group as being right or wrong, it is simply a matter of choice and conviction, and thus a philosophical question.

Let’s look, for instance, at parabens, the infamous preservatives that everybody knows by name. They are synthetic chemicals, esters of para-amino-benzoic acid and have indeed been around for a long time. There are many chemicals similar to parabens in the natural world, which could and likely do have similar anti-microbial properties to synthetic parabens. Plants also have to protect themselves against microorganisms, just as our bodies are protected by the immune system. Over the years there were many accusations raising the issue of parabens’ safety, but none has gained momentum like the recent findings, which state that they have estrogen-like effects, which might further link them to breast cancer. The study that had caused such a stir was very small, based on samples of breast cancer tissue, where the presence of parabens was discovered. They are suspected to have originated from products applied to the under-arm area, or some other kind of body product. Now, that shouldn’t make the news at all, we all know for quite some time that what is applied on the skin gets inside the body. Where will traces of different chemicals appear once they are absorbed, what will happen further, what do they actually do inside the body, if anything, how much is eliminated and how quickly…it is simply not well known. Extrapolate this to many, tens, hundreds perhaps of chemical compounds, both synthetic and natural, that we are exposed to every day and you will begin to understand that we are far from seeing the big picture – we are looking at a rudimentary sketch, at best. The global panic that ensued after this study received publicity from mainstream media would have provided some funding for further research, but it was based mostly on speculations that may or may not be proven true. For now, both the chemists who work in the industry and the Government have rejected the notion that parabens are not safe. They insist that, yes, they are synthetic, but they have been used for a long time, have been researched thoroughly and when used in recommended concentrations have never shown to be harmful.

There is, however, something very peculiar, and exciting, if you wish, that is emerging from this and similar situations: under the pressure from the public, and the loss of revenue of the major companies to paraben-free products, the spotlight has turned to natural preservatives like never before. The research has intensified to find new natural ingredients with anti-microbial effects. There are also some surprising findings about the anti-microbial actions by some of the common ingredients that have been used for other purposes. There have always been scientists and companies that searched for alternatives, but now that the big industry leaders are turning towards and exploring alternative means to preserving personal care products, exciting times lie ahead. This in no way means that preserving cosmetic products got any easier – to the contrary. All of the challenging issues remain the same, plus the complications of formulating with new and often not very well known or understood ingredients. Basically, anybody formulating cosmetic products today is charting their own course – they have to find a method, and preservatives, that will work for their products. There are more options available to them than ever before, and it has never been more complicated.

Natural Preservatives

Do they work? Are they safe? These are the same questions that synthetic preservatives have to answer, and meeting those standards would result with either establishing any of these natural chemicals as preservatives or merely discarding them as yet another failed attempt.

To answer the first question is relatively easy: a challenge test for anti-microbial activity will show whether they are effective or not. Further testing will establish what minimum quantity of the chemical is active as a preservative, which is of extreme importance since the lesser quantity is used, the less there is to worry about in terms of safety. Additional testing will point out exactly how effective the compound is against each of the microbes affecting the formulation. These are standard procedures and the first steps in even considering a compound for a role of a preservative.

Then comes further testing, which has to do with how well does it work with the process of actual production of the skin care product – pH, other ingredients, temperature, packaging etc.

After all that has been passed, the second question remains: are they safe?
In general, natural chemicals with anti-microbial activities are less toxic and well tolerated by the skin. Their efficacy against microorganisms is usually lower than that of the synthetic chemicals. As with conventional preservatives, the wisdom and experience show that it will take a long time and use to fully understand every aspect and the principle by which they work. To be sure, there is a lot of testing being carried on, or has already been done, and the industry, as well as scientists, are not going blindly into it. Besides extensive testing, there is also common scientific knowledge about compounds of similar structure, their effects and toxicity on human bodies. There is also traditional use of those plants in herbal medicine, etc. Knowledge is a complex web, which creates new loops by using nearest ones.

When it comes to natural ingredients, including natural preservatives, there is always an element of trust, or better belief, on the part of both the consumers and people who create them. I admit that myself. And so we are back to philosophy. As a natural-oriented chemist, I will always rather work with a natural compound than synthetic, because it is my strong belief that the synergy between natural elements, such as between natural chemicals and our bodies, works better, superior even, and safer, than the combination with synthetic chemicals. Natural preservatives test this commitment to natural ingredients far more than any other ingredient in skin care products. There are very few, not one works perfectly, satisfactory at best, and the production can be very challenging. In addition, many of them have a rather strong scent, some of them are unstable at certain pH values, temperature affects them greatly, and so on.

Let’s look now at some of the available natural and naturally derived preservatives. Please note that some of these compounds are produced synthetically although they exist in nature, but extraction is very expensive (or production very cheap) and when produced instead of being extracted they become nature identical.

Organic Acids – Benzoic, Sorbic, Boric, Citric and other Alpha-hydroxy Acids.
All of these have been used for a very long time, either as free acids, or as their salts. They are active against fungi, or molds.

Citrus Seed Extract – very popular with alternative formulators, has a broad spectrum of activity and has been on the market for several decades. It has been disputed recently from different angles. One of them asserts that its antimicrobial effectiveness is entirely due to impurities, i.e. presence of conventional preservatives. The original makers of the product do not reveal the procedure or the actual content, but insist that that is not true. However, the original extracted material from the seeds of Grapefruit is being converted to a more stable form, which blurs the line on natural, or naturally derived. Both supporters and opponents hold on to their stands.

Free Fatty Acids and Monoglycerides – these are natural components of oils and have a wide application in creams, due to their emolliency. Some of them, like Glyceryl Laurate, and more recently discovered Glyceryl Caprylate have anti-microbial actions.

Tree Lichen Extract and Usnic Acid – traditionally used for treatment of fungus infections on feet, they are now used as preservatives against fungi and moulds.

Japanese Honeysuckle Extract – it is anti-microbial and also has anti-inflammatory actions.

Hinokitiol and the Hinoki Tree – this is a nature identical compound, but it can still be found as a pure extract as well, at a very high price.

Essential Oils – it is widely known that essential oils have anti-microbial activities, but they are difficult to use as preservatives, specifically because the quantities required are far too high. There are chemical companies that have isolated some of the most anti-microbial components of certain essential oils and they are available as preservatives, although classified as ‘fragrance’. Among them, there are isolates from Tea Tree oil, mixtures of Oregano, Thyme and Cinnamon, some other combine Rosemary, Lavender, Golden Rod etc.

Wassabi or Japanese Horseradish – has both anti-microbial and anti-oxidant activity.

Phytic Acid – extracted from Rice bran, it is a chellating agent, which means that it binds metal ions (necessary for microbe’s metabolism) and disrupts their life cycle.

There are many others as well; it is a rapidly expanding field. However, what all these compounds have in common is that they all have limitations. They are far from perfect. That will be deterrence to some, but not to everybody. In addition, by observing how they protect the plant itself, the scientists stay closely within the natural cycle of things, with its amazing solutions to most problems.

Finding a right ratio of preservatives for a skin care product, whether working with conventional or natural ones, is a long and tedious process, and it is a collaborative effort of many components of that cream.

In this particular rabbit hole we have found that conventional preservatives to conventional chemists are a safe and sound choice, and unconventional preservatives to unconventional chemists are the obvious, and only choice. Both of these groups of chemicals are used in quantities which are effective and safe, as determined by testing and regulations. For some of them, particularly from the group of natural preservatives, there are no regulations in place yet. What protects the public in both cases is the knowledge of formulators and their conscientious choice to make their products safe and effectively preserved.

Can preservatives, including natural ones, be dangerous?
Yes – most of them can cause harm if used in higher than recommended quantities.

Can they cause harm when used in recommended quantities as well?
Generally – no. However, possible long-term effects are very difficult to follow and study.

How does this help you make your decision as a consumer?
Preservatives are a small part of the product you are purchasing. If you are seeking natural products, just as certain chemists seek natural ingredients to work with, then your choice is a natural extension of your approach to life, including skin care. You understand the philosophy behind such products and why certain ingredients are chosen over all other, and the choice is easy.

If you are only concerned about preservatives posing a health risk to you, then the choice becomes difficult. Assessing risk is a job that nobody likes – we would all much rather deal with certainty. Unfortunately, with the issue of preservatives there are sound cons for each pro, and vice versa. This applies to both synthetic and natural preservatives.

What you can do is: arm yourself with tangible and reliable knowledge by connecting to the sources you trust, also, check out the sources you don’t hold in high esteem, if for no other reason then so you can feel good about how much more you know, and always remember that your responsibility lies with choosing what is right for you.

To your beauty and health,

Ivana K.

Natural Skin Care from i2 by Ivana K from Canada
Ivana Knezevic Contributor
Owner , Formulator i2 by Ivana K
Ivana Knezevic is a Cosmetic Chemist, and Owner of i2 by Ivana K in Canada.
Ivana Knezevic Contributor
Owner , Formulator i2 by Ivana K
Ivana Knezevic is a Cosmetic Chemist, and Owner of i2 by Ivana K in Canada.
Latest Posts
  • MicroAlgae use in Skincare Question
  • Question for Ivana K about Telomerase Enzymes
  Organic Web Care offers the Very Best in Web Products, Prices, and Service.  

Similar Articles