Euxyl K712, Natural Preservative, 100 ml

Euxyl K712 is a liquid preservative based on sodium benzoate and potassium sorbate in aqueous solution, designed for cosmetics with acidic pH. It protects creams, shampoos, tonics and shower gels against bacteria, yeasts and moulds, and is used in both rinse-off and leave-on preparations. The manufacturer states that the composition meets the requirements of many standards for certified natural cosmetics and that the preservative is free from parabens, PEG and formaldehyde donors.

It dissolves in water, is added to the water phase or at the end into the finished product, and is dosed in the range of 0.5 – 1.5 %. The requirement is that the pH of the finished formulation is up to 5.5, i.e. within the range the manufacturer describes as skin-friendly.

Key benefits

• Broad spectrum of action – active against bacteria, yeasts and moulds. According to manufacturer data, the efficacy against all three groups is balanced.
• Rinse-off and leave-on products – the same preservative works in a shampoo, shower gel, facial tonic and cream.
• Easy incorporation – liquid form soluble in water, no heating or pre-mixing required. Can also be added subsequently to the finished product.
• Compatibility with surfactants – works in systems with anionic, amphoteric and non-ionic surfactants, covering common shampoo and wash gel formulations.
• For natural cosmetics – the manufacturer declares compliance with the requirements of many natural cosmetics certifications. The composition is vegan, free from parabens, PEG, EDTA and formaldehyde donors, and readily biodegradable according to OECD 301.

Use in formulation

Efficacy is linked to acidic pH. The finished product must have a pH of no more than 5.5; the manufacturer does not state efficacy at higher values. When designing a formulation, therefore, plan to adjust the pH only after all ingredients, including the preservative, have been added.

It is added to the water phase, during the cooling phase of the emulsion or at the end to the finished product. Processing temperature must not exceed 80 °C. For emulsions, the easiest approach is to add it below this threshold during cooling with constant stirring.

The recommended dosage is 0.5 – 1.5 %. In the manufacturer's preservation tests (repeated inoculation with a mixture of bacteria, yeasts and moulds over six cycles), at pH 5 a betaine shampoo, an alkylpolyglucoside shampoo and an O/W milk all remained growth-free, all at a dose of 0.75 %. For more demanding systems, start in the upper half of the range and verify efficacy with your own test.

The preservative protects a cleanly manufactured product. It will not rescue an already contaminated product quickly: the manufacturer states that at least 48 hours of contact are needed to reduce the microbial count. The foundation remains clean production, sanitised equipment and raw materials with a low microbial burden.

Suitable for products such as

• Shampoos, shower and wash gels – surfactant systems that passed the manufacturer's tests at pH 5 with just 0.75 % of preservative.
• Facial tonics and facial waters – aqueous products with acidic pH where the preservative dissolves directly without an auxiliary agent.
• O/W creams and body milks – added during the cooling phase and the pH of the emulsion is fine-tuned after its addition.
• Intimate hygiene preparations and baby cosmetics – application areas listed by the manufacturer as suitable.
• Liquid soaps based on surfactants – only formulations whose pH can be set below 5.5. It is not intended for saponification soap with alkaline pH.

Good to know

The concentrate has a yellowish to brownish colour and a characteristic odour. With white creams and clear aqueous products, it is worth verifying the effect on the finished product in a trial batch.

The concentrate is classified under CLP regulation (pictogram GHS07, irritant). When working with the undiluted preservative, follow the safety data sheet.

Frequently asked questions