Preservatives - how do they work and what are they for?

What are preservatives and why are they needed in a finished recipe?

What are preservatives and how do they work in cosmetics?

What are preservatives is a question that often arises when working with an aqueous or aqueous-oil product. Micro-organisms need water and nutrient solution to grow, and many emulsions, gels or tonics fulfil these conditions. Preservatives inhibit the growth of bacteria, yeasts and moulds, extending the safe time of use of the product and protecting the user from infection. The mechanism of action sometimes varies and depends on the type of molecule and its distribution between the phases of the system: some compounds disrupt the structure of cell membranes, others modify proteins or impede the metabolism of microorganisms. Efficacy is determined not only by concentration and type, but also by pH, presence of solvents, amount of free water and packaging. This is why the preservative in cosmetics should be designed together with the entire formulation and not added at the end.

In practice, a single preservative or a mixture of preservatives that act synergistically against different groups of microorganisms is used. An important role is also played by so-called hurdle factors, i.e. protective barriers - for example, limiting bioavailable water, choosing airless packaging, line hygiene and controlling the raw material supply chain. Preservatives in cosmetics They are therefore responsible not only for durability, but also for the repeatability of the consumer experience between production batches. If you need support in selection and verification, get in touch with the team for whom laboratory work is a daily occurrence - the cosmetics laboratory will check the parameters, perform a literature review and plan the study taking into account the nature of your recipe. Preservatives are not an unnecessary additive, but a real protection for the user and the stability of the product.

Preservatives in cosmetics and user safety and formulation requirements.

Safety assessment and registration documentation vs. choice of preservative system.

Preservatives must be effective in protecting the product against microbial growth, while remaining within acceptable limits and conditions of use. The product dossier describes the type of protection used, the concentrations, the technological justification and the test results. A key element is the safety assessment of the cosmetic product, which analyses tests carried out for the product, such as the stability of the formulation and a challenge test to confirm the effectiveness of the preservative system.

In practice, full tests of the effectiveness of the preservative system in the final product are carried out. In case of formulation changes, the test must be repeated to confirm that microbiological preservation has not deteriorated. Preservatives are also evaluated in terms of their toxicological profile, possible skin sensitivity and compatibility with the user group, for example in products for children. It is also worth bearing in mind difficult substrates, such as formulations rich in humectants or cationic polymers, which can alter the activity of the preservative.

Rounding off the technical part is deciding how to communicate the presence and role of the preservative in your marketing materials and product sheet. If you are keen to ensure that the system works not only in theory, but also in real-world conditions, plan a reliable cosmetics research. In the formal area, you will be supported by the team in processes such as registration of cosmeticsand safety verification will be provided by a dedicated Safety Assessor as part of the service safety assessment of cosmetics. Preservatives in cosmetics should always be juxtaposed with a production hygiene plan and control of storage conditions - they are part of the same puzzle.

Sodium benzoate in cosmetics and benzoic acid in cosmetics - when do they make sense and how to use them?

pH, carrier, concentration and synergy of the preservative system.

Sodium benzoate in cosmetics and benzoic acid in cosmetics are a common choice in aqueous and aqueous-alcohol products. Their action is strongly pH dependent, as it is the free, non-dissociated form of benzoic acid that is responsible for the antimicrobial activity. Formulations are therefore designed so that the pH is within a range favourable to the protonation of the molecule; otherwise, even a higher concentration of preservative will not guarantee protection.

In practice, mixtures are also used with other protective substances that broaden the effect, for example with other organic acids, polyols or preservatives accepted by natural standards. Preservative in cosmetics must be considered in the context of the entire cosmetic formulation - including the base, as different types of polymers, electrolytes and even flavourings can change the position of the preservative between the water and oil phases and alter its effect. For this reason, the challenge test is performed on the finished product and not on the base without additives. In the context of transparent communication, the issue of parabens often comes up - users want to know which compounds from the paraben group are allowed and in which ranges.

The choice of preservative itself, however, is not an argument about name and predilection, but a decision about the scope of action and skin tolerance. Preservatives should always take into account the target user group and the method of application, as a skin cream for a baby and an acid peeling for mature skin will have different requirements. From a design perspective, compatibility with the packaging also matters, such as the ability to interact with the product when it comes into contact with the elastomers of the pump. If in doubt, it is worth consulting the team mpr-labs.com, which combines formative practice with data evaluation. Well-chosen preservatives are the result of working with pH, activity profile and system effectiveness studies, not just the sum of the concentrations in the table.

Natural preservatives, preservatives and preservatives - how to make informed decisions.

How to assess risk scenarios, interpret research and read labels?

Natural preservatives tempt with a simple narrative, but in practice they require the same research discipline as their synthetic counterparts. We are not only talking about molecules of natural origin, but also support systems that lower pH or exhibit chelating activity. Preservatives should be selected for the product taking into account the bioavailable water, the level of raw materials susceptible to degradation and the expected shelf life after opening. There are no shortcuts here - test data always counts. A short checklist that organises decisions and facilitates the conversation between development, production and marketing helps in the day-to-day formulation work:

• Define the use of the product and the viable mode of application, and then select the preservatives to expected contamination and water contact. Then plan a full set of tests, including stability, microbial load and maintenance effectiveness, using services such as cosmetics research.
• Verify the pH and the effect of the accompanying raw materials, as carriers, polymers and electrolytes can significantly alter the activity of the system and the distribution of the preservative in the formulation.
• Evaluate compatibility with the target group and packaging material, and enter the results in the documentation along with the application and storage conditions.
• Link test results to regulatory actions such as registration of cosmetics and final safety assessment of cosmetics.

Preservative is part of a larger quality strategy covering the entire product life cycle, from raw material selection to production hygiene and user education. This is why preservatives in cosmetics should be tested in their target matrix and under actual storage conditions. Working with a team that combines laboratory facilities and an understanding of the business takes the burden of risk off the manufacturer's shoulders and reduces the time to achieve a stable and safe batch. If you want your formulations to undergo reliable testing and documentation preparation, contact us - -. cosmetics laboratory will develop a research plan and help select a layout in line with both the nature of the product and market practice. Preservatives and other microbiological protection elements are data-driven decisions that realistically translate into product safety and reproducibility.

Write to us and see how we can plan effective microbiological protection and documentation of your product from laboratory trials to the finished batch.