Propanediol

Propanediol (1,3-propanediol) is a colourless, viscous liquid often used as a more environmentally friendly alternative to propylene glycol. It has excellent hydrating properties, making it useful in cosmetics such as creams, serums and facial toners, where it acts as a humectant and solvent. In industry, it also serves as a raw material for producing polymers and biodegradable plastics. It is well tolerated by the skin and is considered a safe, gentle ingredient. This substance is obtained by fermenting natural sources, such as corn sugar or glucose from plant materials, making it a renewable alternative to petrochemical glycols. Unlike synthetic propylene glycol, which is derived from petroleum, propanediol supports sustainability and is biodegradable, reducing the environmental footprint of cosmetic products.

Propanediol acts primarily as a humectant, hydrating the skin by binding water from its surroundings and preventing its loss through transepidermal evaporation. It improves the penetration of active ingredients into the deeper layers of the skin thanks to its ability to act as a solvent and penetration enhancer. It supports skin barrier repair by increasing hydration and elasticity without causing irritation. At concentrations of 2-10 %, it significantly improves the sensory properties of formulations, reduces the stickiness of other humectants such as glycerine, and contributes to the overall stability of emulsions.

This ingredient is ideal for dry, dehydrated, sensitive and oily skin, including acne-prone and mature skin. It is recommended for all age groups, particularly those looking for environmentally friendly, gentle ingredients without the risk of irritation. It is suitable for products for children and for sensitive areas such as the eye contour, where it replaces potentially irritating alternatives.

A study published in the Journal of Cosmetic Science (2014) demonstrated that propanediol at a concentration of 5 % improved skin hydration by 25 % after 4 weeks of application compared with a placebo, as measured by corneometry. Further research in the International Journal of Cosmetic Science (2018) reports that at a concentration of 3-7 %, it increased the penetration of niacinamide into the skin by 40 %, enhancing its hydrating and barrier-supporting effects.