Natural Soapmaking (once Soap Naturally) Natural Skin Care Handbooks
Ingredient Information

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Choosing antioxidants and preservatives

What are anti-oxidants and preservatives?

In order to understand what anti-oxidants and preservatives are for, and how they should be used, it is important to first "digest" a few preliminary concepts.

First of all, there is a lot of misleading, and often deliberately wrong information being circulated among natural skin care makers. Creating truly natural, skin friendly cosmetics requires a long and complex learning curve, (which goes well beyond the common habit of "posting a question to the mailing list"), together with a more responsible approach to selecting all the ingredients for handmade skin care. Leaving out synthetic preservatives, and then maybe adding synthetic fragrances "because my customers want a peach scented lotion", doesn't automatically guarantee being in the position to affirm that this product is "completely natural and therefore more skin friendly". Rather, it is not uncommon to find that the skin un-friendliness of some commercial (and handmade) products is directly related to the use of inappropriate fragrancing agents.

Secondly, these misleading statements have regrettably brought forward further confusion about nature, application scope and usage of some important ingredients. In particular, it is sadly common to hear the terms anti-oxidant and preservative being used interchangeably, with frustrating consequences especially for those who find themselves unwillingly opening a "can of worms" by bringing up the subject on some mailing lists. The truth is, anti-oxidants and preservatives are two completely different "beasts", with different nature, different application scope and different usage criteria.


Anti-oxidants are substances that inhibit oxidation. Animal fats and vegetable oils are made up by chemical structures called triglycerides, where one molecule of glycerol is bonded with three molecules of fatty acids, which in turn consist of hydrocarbon chains of variable length. Oils and fats also contain variable amounts of free fatty acids - i.e, fatty acid molecules that are not bonded with any glycerol molecule. The fatty acids in oils and fats can combine with oxidising agents (such as oxigen, for instance, which is present in the air and in water), and oxidise. In other words, the oil (or fat) may turn rancid. Adding an anti-oxidant helps stop or slow down this natural oxidation process, and prolongs the shelf life of the oils. Two "classes" of anti-oxidants are available for manufacturers of natural skin care products:

  1. Substances that, by inhibiting oxidation, effectively prolong the shelf life of oils, and therefore keep oil-based applications fresher for longer periods. These include several types of rosemary extracts, the best known being Rosemary Oleoresin Extract, or ROE, and also citrus seed extracts. Because citrus seed extracts can have negative side effects, rosemary extract is usually preferred. ROE is always best added to the oils before heating, as it also has the effect of impairing dissociation of the fatty acid molecules caused by higher temperatures.
  2. Substances that protect skin cells from the damaging effects of oxidisation, and are typically added as active ingredients. These include Vitamin C, Vitamin E and beta-carotene.

Whenever formulating a new product, it is important to establish whether an anti-oxidant is needed for one or the other reason, and consequently choose the most appropriate. Most importantly, remember that anti-oxidants have no effect on fungi, bacteria, yeast and other living things that may corrupt emulsions and any other water-based cosmetic.


Preservatives are substances that kill bacteria and fungi (or at the very minimum make it very difficult for "living things" to survive), and have no effect on the shelf life of the oils. Bacteria, fungi, yeast and other potentially dangerous microorganisms typically avoid waterless compounds (such as balms, salves, pomades and oil-only blends) and also substances with a relatively high pH (such as soap), but thrive in humid environments. For this reason, soaps and oil-based skin care applications do not need preservatives - but unlike these, creams, lotions and any other compound where water is present require adding a preservative if the shelf life and integrity of the product need to be extended further than 2 or 3 weeks.

It is important to understand that the efficacy of preservatives relies, by definition, on their ability to kill live cells; in other words, their toxicity is an unavoidable component of their reason of being. A number of natural extracts, plants and essential oils contain substances that have the power to effectively kill bacteria, yeast and fungi; however, in many cases these substances are or can be toxic for humans, too. A typical example are citrus or grapefruit seed extracts: although these have natural antimicrobial properties, some of their constituents are thought to be responsible for life-threatening hormonal imbalances. Also, citrus seed extracts are not approved for cosmetic use in Europe and in Japan, and are therefore not an option in those countries.

In the last few months, a new type of natural preservative has appeared on the market. Similar in look, feel and scent to an essential oil blend, and made by combining active fractions of essential oils, this new preservative system seems to have the potential to address the needs of those skin care manufacturers who want their products to be completely natural - yet, being such a new product, some time might be required before its efficacy and possible contraindications are proven once for all.

Among the synthetic preservatives available for handmade skin care products, paraben-based systems seem to be particularly controversial. A large number of articles, books and so-called "expert" opinions point to paraben-based preservative systems as being responsible for the "skin unfriendliness" of many industrial products. However, in-depth medical and scientifical researches show that paraben-based preservatives are by far less dangerous, both for the skin, and for the environment, than most other types of preservatives, such as for instance those that fall into the "formaldehyde donors" category.


When it comes to choosing the right preservative for your lovingly handmade skin care treats, deciding whether you want to rely on a completely natural system or not is a matter of personal choice, which requires a more thorough approach than just "following the trend", and should never be taken lightly. In general, the safest and wisest option is to purchase preservatives from reputable suppliers, who can offer advice on what to choose, why and how to use it (and this, just as with any other ingredient, for that matter!)

As already mentioned, anti-oxidants and preservatives are not unavoidable in skin care preparations; if you are making creams, lotions and balms for personal and family use, and if you are prepared to take on full responsibility for possibly negative side effects, then you can certainly avoid them completely, and be sure that your preparations are just as natural as possible.

On the other hand, preservatives and anti-oxidants can hardly be avoided if you want to sell your products. We have already hinted to the fact the debate on preservatives and anti-oxidants, especially among those who aim for "natural cosmetics", is fierce - and hot are also the discussions about synthetic fragrances versus essential oils, or natural soap versus Melt & Pour bases. We believe that the only way to placate the altercations and give both manufacturers and consumers the power to decide for themselves what is good for them, is to fully understand the implications of using each ingredient, and commit ourselves to appropriate "market niches" based on what we have responsibly and consciously chosen.

Where to buy preservatives for natural skin care

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This page was last updated on 5th March 2006

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