Citric acid

Citric acid – for the optimum pH value

Citric acid is a colourless and water-soluble carboxylic acid. It is a fruit acid and one of the most common acids found in plants. Citric acid is contained for example in lemon juice, apples, pears, raspberries, pine-wood, mushrooms, wine and milk. It also occurs as a metabolic product in all oxygen-consuming organisms. Citric acid has a role in a number of applications, but it is mainly used in cosmetics to adjust the pH value of a product.

About citric acid

INCI name (International Nomenclature of Cosmetic Ingredients name): Citric Acid
Natural (citrus fruits)
Uses: Lip care, skin lotions, creams, bubble baths, peels, hair treatments
Special properties of citric acid: Helps to smoothen skin, adjusts the pH value of cosmetics

What is the pH value?

The pH value indicates whether an aqueous solution is acid or alkaline. The scale for measuring the pH value goes from 0 to 14, with values under 7 indicating an acid solution and those greater than 7 indicating that a solution is alkaline. If an aqueous solution has a pH of 7, this means that it is pH-neutral. Pure water has a pH value of 7, for example.

The pH value of cosmetics products needs to be adjusted to ensure compatibility with the skin. Human skin is acid on its surface. What is known as the skin’s acid mantle ensures that bacteria and harmful germs find it harder to get inside the body through the skin barrier and also find it harder to multiply. The pH value of the skin is roughly 5.5. Accordingly, suitable skin creams should have a similar pH value in order to support and not hinder the natural acid mantle.

Citric acid as pH regulator

Citric acid is the most common ingredient used to give cosmetics the desired pH value. As a rule, only tiny amounts are required. Citric acid can also help to make the skin smooth and supple due to its purifying effect. In addition, the skin can benefit from its high vitamin C content. These properties explain why citric acid is found in many different cosmetics products. It is also used as an ingredient in food products, cleaning agents and water softeners.