Soap is the oldest detergent. Officially, it is an anionic (negatively charged) surfactant, made by the reaction of fat and lye (sodium hydroxide, NaOH, caustic soda). The fat can be animal (tallow) or vegetable, so soap can be animal based or vegetable based. This reaction of fatty acids and alkaline lye is called saponification. There are ancient inspiring stories about soap. Prehistoric hunters found, when cooking food, that animal fat mixed with the ashes of their camp fire, which naturally contain potash (another hydroxide), made it easier to clean their pots and cutlery. And in Roman history, animals were sacrificed on the Mount Sopa (what’s in a name?), washing down a mixture of animal fat and ashes down to the clay shores of the river Tiber. Clay soil contains chalk with high pH, like lye and potash. Women washing textiles at the shores of the river, found that cleaning went better on the soil at the bottom of the Mount Sopa. The first real evidence of the use of soap was reported by the Egyptians. The first manufacture of soap from vegetable fats is described by Muslim chemists in the Middle Ages.

The disadvantage of soap is that it forms an insoluble precipitate together with calcium. From experience, we all know that a visible haze arises when using soap in hard water. This is why soap is mostly used in bars for washing our hands, and for hand washes. Soluble anionics, such as sulphonates have replaced the original “sodium salts of fat”. They give crystal clear solutions.

The soap bars we know are mostly produced from palm oil. The ratio between palm oil and palm kernel (seed) oil is normally 80/20 or 90/10. Other sources of fat are coconut and olive oil. Luxury fats like Shea Butter, Jojoba Oil but also the oils from pistachio and mango seed claim to contribute to skin health. Animal fat has become a minor source. The main producing countries where saponification takes place are Malaysia and Indonesia. The soap is produced in the form of noodles. These noodles are shipped all over the world. Soap bar producers add their fragrances and colors and press the soap noodles into the eventual bars and other fantasy forms, much like extrusion of plastic objects from polymer granulates.

The presence of glycerin has a plasticizing effect on the soap noodles and bars. This facilitates extrusion of complex shapes and makes the soap bars resistant to scratches and cracks. High glycerin as well as richly fatted soaps are marketed as humectants for the skin.

Soap noodles are not required to be pre-registered under REACH (Commission Regulation EC No 987/2008 Annexes IV, V).

The Sirius Effects

Compatibility
We have noticed color changes when using alkali soap noodles. Some pigments react with alkaline soap. This can cause both lighter colors (Unipure/Covanor Red becoming pink) as well as darker colors (Jaune Citron becoming dark green). Sirius supplies soap noodles with free fatty acids and soap noodles with free alkaline matter for compatibility with any pigment or additive.

Solubility
As described above, soap leaves a haze upon dissolving. We have found that the addition of a little (0.6-0.8%) table salt increases the ionization power and thus the solubility at 30oC.

Transparency
Sirius supplies soap noodles which enable you to produce transparent soap bars. The soft transparent, more flake-like, noodles are a blend of Sodium Cocoate, Sodium Stearate, Water, Propylene Glycol, Sugar, Sodium Lauryl Ether Sulfate (SLES), Cocamidopropyl Betaine, Glycerin, Sodium Chloride (salt), Disodium EDTA and BHT. The pH is 9-10.5 but the free alkalinity is zero.

Sustainability
Not too long ago, forests were destroyed to make room for palm oil plantations to feed the world demand for soap bars and biodiesel. We, and many with us, believe that, nowadays, all parties in the supply chain should make sure that the palm oil is produced in a sustainable way. This means that the harvest of palm oil should not threaten the environment in the producers countries while downstream, we wash our hands in innocence.

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+31(0)355485898 | info@siriusint.com | http://www.siriusint.com

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