Preservative-Free: The Rise of Refrigerated Cosmetics

NATURAL ORIGIN OF RAW MATERIALS USED IN COSMETICS has in recent years become not merely a fashionable trend, but an outright necessity. Until quite recently, only a small proportion of suppliers provided declarations confirming the natural origin of their ingredients; today, this has become an established standard. The fact that this phenomenon is not a passing fad, but rather a process firmly rooted in our collective awareness, is demonstrated by the emergence of increasingly new and sophisticated directions within natural cosmetics.

Today, the main directions in natural cosmetics include:

• vegan – the raw materials used in the products are exclusively plant- or mineral-derived;

• clean beauty – a short, minimalist ingredient list based on the principle that less is more. For example, instead of using five different ingredients, a single ingredient may be used at a higher, effective concentration. There is no room here for “marketing” quantities of raw materials;

• preservative-free according to Annex V – this refers to conventional preservatives with a strictly defined permitted concentration in the finished product (e.g. Sodium Benzoate, DMDM Hydantoin). Instead of these well-known ingredients, alternatives are used, i.e. substances with microbiostatic properties and preservation boosters, such as Pentylene Glycol, Caprylyl Glycol, Hinokitiol and Sodium Levulinate;

• preservative-free – this is a very narrow niche in which no microbiostatic substances are used to protect the cosmetic bulk from microbial contamination; instead, only preventive measures are implemented.

The latter is becoming increasingly popular, but for cosmetic formulators it presents a considerable challenge. Why?

Technological requirements – formulation

To create a good preservative-free cosmetic, the formulation must be very carefully designed. First and foremost, active ingredients should be selected that do not contain substances commonly understood as preservatives (e.g. Sodium Benzoate or Phenoxyethanol), so that they do not ultimately appear in the product’s INCI list. Liquid botanical extracts are commonly preserved with sodium benzoate and potassium sorbate or phenoxyethanol.

However, it is worth knowing that they are also available in “preservative-free” versions, based on high concentrations of glycerin or glycols, which inhibit the proliferation of microorganisms. Instead of liquid extracts, dry extracts can be used. These are generally available in powder form and, apart from a carrier substance (e.g. maltodextrin), contain no additional ingredients.

The second important element is ultra-pure water – the purer the water, the longer the cosmetic can remain free from microorganisms. Another consideration is the selection of base ingredients, namely humectants (e.g. glycerin, Pentylene Glycol), emollients (e.g. Tripelargonin, Isostearyl Isostearate), oils (e.g. Persea Gratissima Seed Oil), emulsifiers (e.g. Glyceryl Stearate Citrate, Sorbitan Stearate) and pH regulators (e.g. Lactic Acid, Citric Acid), all of which must be of the highest quality and purity.

Although microorganisms cannot proliferate in oil or wax, they may still be present in a dormant or spore form and begin to activate once they come into contact with water. Therefore, as early as the product development stage, it is essential to identify suppliers offering raw materials of the highest possible purity, preferably freshly manufactured.

Technological requirements – production, filling and transport

Standard production processes can present a variety of challenges. Residues of products often accumulate in hard-to-reach areas of production equipment and installations, providing a nutrient source for microorganisms. In addition, formulators must deal with the resident microflora of the manufacturing facility and select appropriate cleaning and disinfection agents.

Another sensitive point is the raw material warehouse and weighing area. During the preparation of ingredients for the manufacturing process, they can become contaminated through contact with the outside of the packaging and subsequently with the raw material itself. Only the highest hygiene standards and strict adherence to procedures can help prevent this.

The production of preservative-free cosmetics is a significant challenge. All equipment must be disinfected, process water must be perfectly clean, all raw materials must be prepared and protected against contamination, and employees must wear appropriate protective clothing.

It is also worth mentioning that preservative-free cosmetics are best manufactured in very small batches, allowing the product to be sold before its shelf life expires. The larger the quantity produced, the greater the risk that part of the product will have to be discarded because its expiration date has passed.

Another critical point is the filling of the finished product. Every contact between the cosmetic bulk and the air creates an opportunity for contamination. Therefore, it is advisable to use HEPA filters and UV lamps, while filling should be carried out in a closed system.

The packaging of a product intended to be stored in the refrigerator should be carefully considered. In practice, the only suitable options are airless packaging or single-use/single-dose packaging, such as twist-off capsules or mini sachets. Although this is not an environmentally friendly solution, it is the price we pay for eliminating preservatives that would otherwise protect the product.

Our surroundings, as well as our hands and mucous membranes, are home to dozens of strains of microorganisms. Therefore, preventing contact with the cosmetic bulk is the only optimal form of protection. Other types of cosmetic containers are unsuitable for refrigerated products. A pump in a conventional bottle introduces air containing fungal spores into the package, while a jar – the least hygienic option – exposes the product to microorganisms present on our hands every time it is opened and used.

The final critical point is transport. It must be short and efficient to prevent the product from overheating.

The packaging should provide effective insulation against ambient temperature. On a hot summer day, the temperature inside a transport truck trailer can rise significantly above 40°C. Domestic transport is therefore preferable, as international orders with extended delivery times represent a considerable risk.

Key benefits

The greatest advantage of refrigerated cosmetics is their clean, short ingredient list. Since only a small number of raw materials are used, the desired efficacy is achieved through their high concentrations. In addition, a chilled product has a refreshing effect on the skin, reduces puffiness under the eyes and constricts capillaries.

The steadily increasing number of people suffering from skin allergies and hypersensitivity to certain chemical substances means that refrigerated cosmetics, due to their limited ingredient lists, are becoming a genuine alternative for sensitive-skin care.

There is also another extremely important aspect to consider: the absence of preservatives means no direct interference with the skin microbiome. Disruption of the balance and functioning of individual microbial strains is associated with numerous conditions, including atopic dermatitis (AD), psoriasis, acne and others. The absence of preservatives that could potentially destabilize the microbiome may therefore have a positive impact on the care of problem skin.

Cosmetics not for everyone

Preservative-free cosmetics are a specific type of product intended for a relatively narrow group of consumers. This is not necessarily due to skin type or the ingredients themselves, but rather to the storage requirements and short shelf life.

Using these products requires consistency. They are not suitable for a customer who may forget to use them or accidentally leave the product outside the refrigerator overnight. It is also worth remembering that taking such products on long journeys without access to refrigeration is not advisable, as storing them outside refrigerated conditions promotes microbial growth.

If you are planning a longer holiday, you should carefully plan your purchase so that the product does not reach its expiration date while you are away. Otherwise, both the product and your money may go to waste – and cosmetics of this type are far from inexpensive.

Where does the price come from?

The specific production and filling requirements, short shelf life, highest-quality raw materials, small but frequently produced batches, microbiological testing of every batch, high concentrations of active ingredients, costly packaging (airless packaging is among the more expensive options), as well as appropriate transport, are all reflected in the final price of the product.

Premium cosmetics

Carefully selected ingredients, a high price and an extremely narrow target audience are undoubtedly factors that allow these products to be described as high-end.

For the average consumer, cosmetics with such specific requirements are unfortunately beyond their budget and remain little more than a curiosity spotted on the channel of their favorite influencer. Interestingly, even for such a small target group, additional accessories are being developed, such as mini refrigerators that can easily fit on a dressing table or chest of drawers. Such products appeal to the imagination of consumers who aspire to a premium lifestyle.

For some customers, refrigerated cosmetics are an absurd extravagance; others no longer want to use anything else. They certainly have significant advantages, but equally considerable drawbacks. Fortunately, the cosmetics market leaves little room unfilled, and consumers can find something that suits them – a product tailored to their beliefs and requirements.

Zuzanna Fedyczak dla biotechnologia.pl 4/2021 s. 44