Preservatives in cosmetics | Article

Preservatives in cosmetics are a sensitive topic and therefore we want to explain to you that preserving is not bad, but actually indispensable.

Preservatives are substances that prevent the multiplication of bacteria (gram+ and gram-), yeasts, fungi and moulds by disrupting the cells and spores where they germinate, and thus make their growth impossible, thereby extending the shelf life of your product, on average by 2 to 3 months.

They are an indispensable part of products that contain water, not only pure water, but also water-based raw materials, such as hydrosols or aloe vera gel. However, it must be kept in mind that basically most purely natural products are more prone to the formation of microorganisms.

PRESERVATIVES IN COSMETICS FACT OR MYTH?

It is really very likely that your product can be contaminated even if you work under hygienic conditions and everything is clean.

We will list several of the most essential factors that literally make your natural product a paradise for the formation of microorganisms:

- high water content

- humidity of the environment in which the product is stored or used – a humid and warm bathroom environment becomes ideal for the growth of bacteria

- content of hydrosols, plant extracts or dried plants in the product

- content of clays or natural gums in the product

- temperature of storage and temperature at which the product is applied

- pH value approximately from 4.5 to 6.5 (in fact, bacteria can thrive in the range of pH 4 to 9, yeasts and moulds from 3 to 9)

Is it necessary to preserve anhydrous products?

It is not necessary to preserve all products. For example, soap made by the cold process, where a sodium hydroxide solution was used, does not require a preservative.

However, if you have a product without water into which water from the surroundings gets, it is recommended to preserve such a product.

ATTENTION! Do not be misled by the oil base of your product. If you were to use an oil-soluble preservative, the preservative would remain in the oils, it would not move and act exactly where the water is located, which means its use would become pointless. It is therefore necessary to use a water-based preservative and ensure its mixing with the oil phase by adding an emulsifier.

Think about your health

The very fact that you have chosen to make your own natural cosmetics shows that your health is your priority. Therefore, do not underestimate the possibility of the occurrence of bacteria, which, in the case of reduced immunity or damaged skin, can cause unpleasant health problems. Although we cannot see them with the naked eye, they are present in your product in an appropriate amount and are not visible with the naked eye even in the initial stage of their overgrowth.

We would also like to point out the excessive application of preservatives into your products. It is not true here that the more, the longer your product will last. Preservatives are used to a minimal extent, from 0.5 to 4%. Remember that just as they destroy bacteria, they can also destroy your skin in a high proportion. Therefore, always follow the recommended dosage.

PRESERVATIVES IN COSMETICS – HOW TO CHOOSE THE RIGHT ONE

Learn to read product information correctly

Today you will find a large number of preservatives on the market. You can choose a natural or a synthetic one. Sometimes even the name of the preservative itself is quite confusing, it is often the trade name of the product or just an abbreviation. It is therefore important to know how to read product information: the INCI, which should contain all the components of the product, and you can already check those. It is also interesting information if the product is approved for use in natural cosmetics by certification bodies such as COSMOS, Ecocert, Natrue or Soil Association.

Suitability of a preservative based on the nature of your product

The nature of your product plays an important role, so it is necessary that you have defined what kind of product it is. Here are some basic questions:

- Is it a water-based product, such as a toner?

- Is it a W/O or O/W emulsion? (more about the differences between W/O and O/W emulsions in our article O/W or W/O?)

- Is it a product that is rinsed off after application or left on the skin?

- Is the product applied to the hair, the skin around the eyes, the face, the whole body or is it baby cosmetics?

pH value of the product

Another important point is pH. It is very important to realise that most natural preservatives are weak acids (such as salicylic acid, benzoic acid, sorbic acid, etc.). All of them are slightly soluble in water as acids, therefore most of them are supplied as sodium or potassium salts, for example sodium benzoate. But they are effective only in the acid form. This means that in order to introduce them into the product, you will need the sodium or potassium salt, but in order for them to be effective, the acid form will be necessary.

Why then measure the pH of the product carefully?

Because pH significantly affects the effectiveness and solubility of the preservative. If the pH is low, the preservative will start to sediment in the product and can cause destabilisation of the product. If, on the other hand, the pH is high, the preservative loses its effectiveness.

Therefore, check at which pH the given preservative is effective. We remind you that bacteria can thrive in the range of pH 4 to 9, yeasts and moulds from 3 to 9, which includes the pH of the skin of 4.0–6.5.

Preservative substances in the ingredients of your product

This is a very important matter! Before you choose a preservative, you have to take into account the fact that some ingredients from your formulation may already contain a preservative component (for example, hydrosols are often preserved with sodium benzoate). First of all, it is therefore necessary to choose a preservative that is compatible with the preservatives in the raw materials and at the same time calculate how much preservative preparation you can still use so that you do not exceed the correct level and „overdose“ your final product. The application dosages of individual preservatives range from 0.8% to 4.0%.

PRESERVATIVES IN COSMETICS – SPECTRUM OF EFFECT

When choosing the right preservative, it is just as important to check against which contaminating substances the preservative is effective. In cosmetic products, gram-positive, gram-negative bacteria, yeasts and moulds occur most frequently.

Therefore, if you have a preservative at home that does not cover this whole range of contaminants, it is necessary to supplement its effectiveness with an additional preservative.

Influence of the preservative on the character of the final product

Yes, this can happen, especially with natural preservatives, which are extracts from nature and therefore most of them have their own scent and colour. However, do not be discouraged, their use is at most up to 4%, and if you do not want your product to be completely without scent and odour, you will not notice the preservative in it.

In the case of emulsions, it is necessary to monitor any undesirable changes in viscosity.

However, it is again only about practical testing and finding the most suitable one for your product.

It is also important to check whether the given preservative is not sensitive, for example, to light, as a result of which it oxidises. Therefore, consider this aspect as well and choose the right packaging for your preserved product.

Since more and more producers of natural cosmetics are beginning to appear in our circles, who do not produce only for their own needs, the list given is dedicated precisely to them.
In your home conditions, it will be sufficient if you start by choosing a preservative that is effective mainly against the type of bacteria whose multiplication you need to prevent and use the correct ratio of preservative in your product.

PRESERVATIVES IN COSMETICS – OVERVIEW

In our offer you will find both natural and preservatives of synthetic origin.

In this case it is not so important which origin of raw material you choose, but rather that you use a preservative that has effectiveness over the range of action of microorganisms whose multiplication you need to prevent.

If you are a manufacturer of cosmetics, you certainly already have this information determined and you know exactly which preservative is best for your products. In this case we recommend having a microbiological test carried out in a laboratory as well, because this is the only guaranteed way to check whether the chosen preservative is effective.

However, if you produce at home for your own purposes, you do not need to worry so much about determining this. Simply choose a preservative with the widest spectrum of effectiveness. If you produce reasonable quantities that you can use up within a few months, the preservative will effectively protect your product during that period from the overgrowth of undesirable microorganisms.

GRAPEFRUIT SEED EXTRACT

This is a natural product that acts as a natural antibacterial, antiparasitic, antifungal and antiviral inhibitor in soaps, facial toners and other cosmetic products.

It is soluble in water, alcohol and organic solvents.

The most effective range is at pH 1.5–3.0.

Use and application: As far as products on a water basis are concerned, we recommend supplementing with other preservatives to cover effectiveness against microorganisms.

Fragrance: light citrus scent

Colour: light yellow

COSGARD

Cosgard is a natural preservative that meets the standards of Ecocert and COSMOS, NaTrue Certified and Soil Association – dehydroacetic acid and benzyl alcohol are organic compounds that are accepted for use in natural cosmetics.

It is soluble in oil, its effectiveness is at pH 2–7, being most effective below pH 5.5.

Effectiveness: broad-spectrum, highly effective against gram+ bacteria, partly against gram- bacteria and fungi

Dosage: 0.5–1.15%

Its use is really wide. You can use it in the following products:

shampoos, conditioners, facial and liquid soaps, shower gels, facial toners for sensitive skin, baby wipes and cloths, moisturisers, creams, baby shampoos, hair preparations, bubble baths, sunscreens.

Fragrance: it is almost odourless, so it lets the added fragrances of the product stand out

Colour: slightly yellowish tinge, which is slightly visible in clear toilet waters, in other cosmetics it does not influence the colour of the final product.

DERMOSOFT 1388

Dermosoft 1388 is a mixture of organic acids derived from plants with broad antimicrobial activity, certified by Ecocert. It is therefore a natural preservative.

It is soluble in water, effective at pH 5.0–5.5.

Effectiveness: against bacteria (gram+ and gram-) and fungi

Dosage: 3.0–4.0%

Use: water-based products, from gels to emulsions (if the product is oil-based, it is necessary to use a solubiliser)

TIP: You can increase its activity by using 0.1% of the natural chelating agent PA-3.

If you want to increase its effectiveness against yeasts, we recommend combining it with GMCY.

Colour: colourless to pale yellow

DERMOSOFT GMCY

GMCY is a purely natural product – it is an ester of glycerin with caprylic acid, certified by Ecocert. In addition to being a preservative, it is also used as an emulsifier and emollient.

It is soluble in oils and alcohol and effective at pH 4.5–7.0 (in the case of the water phase it is incorporated using a solubiliser).

Effectiveness: against bacteria (gram+ and gram-)

Dosage: 0.3–0.5%

It combines very well with Dermosoft 1388 to achieve a broader spectrum of effectiveness.

Colour: white (it is solid, it melts already at 30–35 ̊C)

NATICIDE

Naticide is a natural preservative. Interestingly, it is actually a fragrance (a mixture of vanilla and almonds), so after its use it is possible to state that your product is preservative-free, because it is not classified as a traditional preservative.

It is soluble in oils and alcohol, in water only up to 0.6% (therefore the remaining 0.4% must be added in the cooling phase), its effectiveness is at pH 4–9.

Effectiveness: effective against gram+ and gram- bacteria, yeasts and moulds

Dosage: 0.3–1%

Use: facial toners (oil-based and dry), face creams and masks, shampoos, antiperspirants, body milks and gels

Colour: slightly yellowish tinge

VERSATIL TBG

This is a preservative approved by Ecocert, COSMOS and Natrue.

It is not soluble in water, therefore a solubiliser is needed to incorporate it into the formulation.

It works on a water base. Its effectiveness is at pH 4.6–6.0.

Effectiveness: effective against gram+ and gram- bacteria and yeasts (for emulsions and water-based products it is sufficient, for shampoos, soaps and surfactant-based products it is necessary to supplement its effects with another preservative).

Dosage: 1.0–1.5%

Use: toners, gels, emulsions, deodorants, hair conditioners

TIP: For better effectiveness, you can combine Versatil TBG with Dermosoft 1388.

Colour: colourless

EUXYL PE 9010

Euxyl is a synthetic broad-spectrum preservative, effective against gram+, gram- bacteria, yeasts and moulds. It does not contain parabens or formaldehyde.

It has limited solubility in water (1% at 20 °C), but is easily soluble in polar solvents such as propylene glycol and 1,3-propanediol. It is slightly soluble in glycerol and sorbitol. Its effectiveness is up to pH 12.

Dosage: 0.5–1.0%

Use: creams, facial lotions and serums, wet wipes, shampoos, conditioners, body care cosmetics

Colour: light yellow

We believe that we have provided you with a sufficient information base in our posts and we keep our fingers crossed for you when testing our preservatives.

The article was prepared for you by

Martina Oboňová