Zinc coco-sulfate is an anionic surfactant derived from coconut oil, primarily used in cosmetic and personal care products such as shampoos, body washes, and cleansers. It is valued for its cleansing, foaming, and conditioning properties. Zinc Coco-Sulfate is similar to Sodium Coco-Sulfate, but it contains zinc instead of sodium, making it gentler on the skin and hair compared to other sulfate-based surfactants.

Chemical Composition and Structure

Zinc Coco-Sulfate is a zinc salt of a sulfonated fatty acid derived from coconut oil. Its chemical structure consists of a chain of fatty acids (primarily lauric acid) from coconut oil that has been sulfonated and combined with zinc. This structure makes it an effective surfactant capable of lowering surface tension between water and oil, allowing it to remove dirt and oils from the skin and hair.

Physical Properties

Zinc Coco-Sulfate is generally available as a white powder or granules and is water-soluble. It is highly foaming, making it ideal for use in cleansing products such as shampoos and soaps. Unlike other sulfate surfactants, the presence of zinc makes it less harsh, providing effective yet gentle cleansing.

The name defines the structure of the molecule:

• Zinc refers to the zinc ion present in the compound. Zinc is used to enhance the detergent properties and stability of the product.
• Coco refers to the fatty acid derived from coconut oil that is attached to the sulfate group. This is typically a mixture of fatty acids, so the exact structure may vary.
• Sulfate refers to the sulfate group that is attached to fatty acid, a salt or ester of sulfuric acid. Sulfates are commonly used in personal care products as foaming agents and cleansers.

The synthesis process takes place in several stages:

• Preparation of raw materials. The raw materials for the synthesis of coconut-sulfate zinc are coconut oil, sulfuric acid and zinc.
• Sulfation. Fatty acids derived from coconut oil react with sulfuric acid to produce coconut sulfate.
• Adding zinc. Zinc is added to coconut sulfate to form coconut-sulfate zinc.
• Purification and drying. The resulting zinc coconut sulfate is purified, typically through filtration and washing, and dried.

Form and Color.

Zinc Coco-Sulfate typically comes as a solid in the form of granules or flakes. It is white or slightly yellowish in color.

What it is for and where

Zinc coco-sulfate is widely used as a surfactant in personal care and cosmetic products. It is found in shampoos, shower gels, soaps, and other cleansing products, where it contributes to foam formation and the removal of dirt and sebum from skin and hair. 

Cosmetics

It is a restricted ingredient as III/24 a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009. Ingredient at risk: 

Water-soluble zinc salts with the exception of zinc 4- hydroxy-benzenesulphonate (entry 25) and zinc pyrithione (Annex II, entry 1670)

Zinc coco-sulfate is a type of surfactant, a compound that lowers the surface tension between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants can act as detergents, wetting agents, emulsifiers, foaming agents and dispersants.

Cleansing agent. Ingredient that cleanses skin without exploiting the surface-active properties that produce a lowering of the surface tension of the stratum corneum. 

Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable and are used to soothe or soften the skin and emulsify, so they need a specific, stabilising ingredient. This ingredient forms a film, lowers the surface tension and makes two immiscible liquids miscible. A very important factor affecting the stability of the emulsion is the amount of the emulsifying agent. Emulsifiers have the property of reducing the oil/water or water/oil interfacial tension, improving the stability of the emulsion and also directly influencing the stability, sensory properties and surface tension of sunscreens by modulating the filmometric performance.

Surfactant - Cleansing agent. Cosmetic products used to cleanse the skin utilise the surface-active action that produces a lowering of the surface tension of the stratum corneum, facilitating the removal of dirt and impurities. 

Studies

This study assessed the anti-malodor efficacy of toothpaste containing 0.2% zinc sulphate after a single brushing and following extended use....Both clinical studies independently support the efficacy of the test toothpaste with 0.2% zinc sulphate in reducing oral malodor after a single brushing, and after four weeks for 12 hours after brushing compared to a toothpaste without zinc ions (1).

Safety

This surfactant is believed to be safe in usage practices and the concentrations described in the safety assessment (2).

• Molecular Formula: C₂₄H₅₀O₈S₂Zn
• Molecular Weight: 596.156
• CAS: 22397-58-6

Synonyms:

• zinc dodecyl hydrogen disulphate
• Bis(dodecyloxysulfonyloxy)zinc

References____________________________________________________________________

(1) Navada R, Kumari H, Le S, Zhang J. Oral malodor reduction from a zinc-containing toothpaste. J Clin Dent. 2008;19(2):69-73. PMID: 18763690.

Abstract. Objective: To evaluate the anti-malodor efficacy of toothpaste containing 0.2% zinc sulphate after a single brushing and following extended use....Conclusion: Both clinical studies independently support the efficacy of the test toothpaste with 0.2% zinc sulphate in reducing oral malodor after a single brushing, and after four weeks for 12 hours after brushing compared to a toothpaste without zinc ions.

(2) Fiume M, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr, Shank RC, Slaga TJ, Snyder PW, Alan Andersen F.  Final report on the safety assessment of sodium cetearyl sulfate and related alkyl sulfates as used in cosmetics. -  Int J Toxicol. 2010 May