sodium hydroxide
Sodium hydroxide in cosmetics: benefits, risks and alternatives
Caustic soda, also known as sodium hydroxide, is a chemical used in many fields, including the cosmetics industry. But why is sodium hydroxide used in cosmetics and what alternatives are there? In this article, we take a closer look at the role of sodium hydroxide in cosmetics and clarify whether it is really necessary.
What is caustic soda?
Sodium hydroxide is a strong alkaline solution that is created by dissolving sodium hydroxide in water. It is valued in industry for its versatile properties, especially for pH adjustment. In cosmetics, sodium hydroxide is mainly used to adjust the pH of a product to make it more skin-friendly.
Why is sodium hydroxide used in cosmetics?
The main function of sodium hydroxide in cosmetics is to regulate pH. Many cosmetic raw materials such as fatty acids or surfactants have an acidic pH, which can be unfavourable for the skin. Sodium hydroxide is added to adjust the pH of a product to a level that is kind to the skin.
Examples of the use of sodium hydroxide in cosmetics:
Soap production: sodium hydroxide is used in the saponification of fats and oils to produce glycerine and soap.
pH adjustment: creams, shampoos and other water-based formulations are often neutralised with caustic soda.
Peelings and chemical treatments: Sodium hydroxide is also used in very small quantities to optimise the stability of acidic AHA/BHA peeling products.
The skin’s optimal pH
The skin has a slightly acidic pH between 4.5 and 5.5. This so-called protective acid mantle is important for protecting the skin against harmful microorganisms and environmental influences. Products that fall outside this range can disrupt the skin’s protective acid mantle and lead to dryness, irritation or infections.
Sodium hydroxide is frequently used in cosmetics to adjust the pH value of a product to the optimal range. But this raises the question: aren’t there better alternatives?
Arginine and lysine as innovative alternatives for pH regulation
Besides the traditional alternatives such as lactic and citric acid, amino acids such as arginine and lysine are increasingly gaining in importance as pH-regulating substances in cosmetics. These natural building blocks of proteins have the advantage that they not only adjust the pH of formulations to the desired range, but also have skin-caring properties.
Arginine: This basic amino acid is often used in skin care products because it gently raises the pH without irritating the skin. Arginine also has moisturising and regenerative properties that make it ideal for sensitive or dry skin.
Lysine: This essential amino acid also has excellent pH-regulating properties and supports the skin barrier at the same time. Lysine is valued in skin care because it has a soothing effect and promotes collagen formation, which makes the skin appear smoother and firmer.
In contrast to caustic soda, arginine and lysine actively contribute to the care and health of the skin. Due to their dual function as pH regulators and active ingredients, they are used primarily in high-quality, nature-oriented cosmetic products. They offer a gentle but effective alternative that enhances both the functionality and the positive image of a product.
Sodium hydroxide on the packaging: an image problem?
The INCI designation Sodium Hydroxide can be found on many cosmetic products, which often leads to confusion among consumers. The term ‘caustic soda’ is often associated with chemical processes and cheap production. In fact, however, it is a widely used and approved ingredient in cosmetics.
The problem lies less in the substance itself than in the perception: many consumers avoid products on whose packaging sodium hydroxide or soda is written because they interpret this as an indication of inferior chemicals.
Conclusion
Sodium hydroxide plays an important role in cosmetics, especially in regulating pH. However, sodium hydroxide is a cheap chemical. Nevertheless, it is not without alternatives: arginine and lysine offer gentler and often better-perceived alternatives. Consumers who read sodium hydroxide on the packaging often interpret this as an indication of an inferior ingredient – a risk to the brand image.
Cosmacon has many years of experience in developing innovative formulations and offers ready-to-use alternatives to sodium hydroxide so that ‘sodium hydroxide’ does not have to appear on the final packaging – for cosmetic products that are both effective and consumer-friendly. Let us advise you!
Literature:
Synergistic effects of arginine and fluoride on human dental biofilm control.
Kuriki N, Asahi Y, Okamoto M, Noiri Y, Ebisu S, Machi H, Suzuki M, Hayashi M.J Dent. 2024 Oct;149:105307.
Kim H, Kwak I, Kim M, Um J, Lee S, Chung B, Park C, Won J, Kim H.Pharmaceutics. 2024 Sep 30;16(10):1283.
Short-Term l-arginine Treatment Mitigates Early Damage of Dermal Collagen Induced by Diabetes.
Miler I, Rabasovic MD, Askrabic S, Stylianou A, Korac B, Korac A.Bioengineering (Basel). 2024 Apr 21;11(4):407.
Polylysine for skin regeneration: A review of recent advances and future perspectives.
Zarrintaj P, Ghorbani S, Barani M, Singh Chauhan NP, Khodadadi Yazdi M, Saeb MR, Ramsey JD, Hamblin MR, Mozafari M, Mostafavi E.Bioeng Transl Med. 2021 Nov 5;7(1):e10261