Schärer & Schläpfer AG has always manufactured Serepon. Now it is investing in a new plant. What does it expect from this, what does it mean for the customers, and what is Serepon, also known as Turkey Red Oil? In loose succession, we want to explore these and other questions. In Part 1, we highlight the history of Turkey Red Oil.

The history of Turkey Red Oil – connection with history

Since its founding year in 1947, Schärer & Schläpfer AG has been producing sulfonated castor oil, a dispersant that is marketed under the product name Serepon. It is also known as Turkey Red Oil (INCI name: Sulfated Castor Oil). It is considered the forerunner of modern synthetic surfactants and is still popular in the leather and textile industries, as well as in eco-detergents and cosmetic and personal care products, such as lipsticks, bath oils and shampoos. "Since the beginning of the pandemic, we have been mixing a hand disinfectant for ourselves. We add a little Serepon to it so that it doesn't dry out our hands," says Roland Borner, Head of Development. "People love it because it makes their hands wonderfully fine."

Serepon is thus one of the first products of Schärer & Schläpfer AG. The substance itself, however, has an even longer history. In 1834, the German chemist Friedlieb Ferdinand Runge (1794-1867) produced the precursor of modern synthetic surfactants: sulfonated oil from sulfuric acid and olive oil. Later, the olive oil was replaced by the cheaper castor oil. The result was Turkey Red Oil.


"People love it because it makes their hands wonderfully fine."

Runge also did pioneering work in paper chromatography, was the first to isolate caffeine, and became known for his work on the technical utilization of coal tar, which at that time was produced in large quantities in the manufacture of illuminating gas and coke from hard coal: waste that had to be disposed of. From this, Runge isolated, characterized and named substances such as aniline, quinoline, pyrrole or phenol – basic building blocks for numerous products of the chemical industry from the second half of the 19th century.


But back to the Turkey Red Oil. The clear, mostly amber to dark red water-soluble liquid was initially used as a leveling agent, i.e. solubilizer, for the color turquoise red. Hence the name. If the oil is added during dyeing, the color penetrates better into the textile fibers. The same applies to the water when washing. This is thanks to the very good emulsifying and wetting effect of Turkey Red Oil, which is also known as Tournant oil. Or just Serepon: the most traditional product of Schärer & Schläpfer AG.