What is Span S-60?

Span S-60 is a classic nonionic water-in-oil (W/O) emulsifier, chemically named sorbitan monostearate, widely used in food, cosmetics, pharmaceuticals, and industrial fields.

Detailed Explanation

Span S-60 (Span 60), chemically named Sorbitan Monostearate, with CAS number 1338-41-6, appears as a light yellow to brown waxy solid or beads. It belongs to the nonionic surfactants category, containing both hydrophilic sorbitol hydroxyl groups and lipophilic long-chain stearate ester groups in its molecule. This unique molecular structure endows it with excellent interfacial activity.

The core characteristic of Span S-60 is its outstanding water-in-oil (W/O) emulsifying ability, forming a strong interfacial film at the oil-water interface to produce stable water-in-oil emulsion systems. This product maintains stable performance over a wide pH range (acidic and alkaline environments) and under hard water conditions, and can be flexibly compounded with hydrophilic surfactants such as the Tween series to precisely adjust the HLB value, meeting the differentiated emulsification performance requirements of various systems.

In terms of safety, Span S-60 has extremely low acute oral toxicity (rat oral LD₅₀ > 15,000 mg/kg), classified as a low-toxicity substance. It has been approved as a food additive (EU number E491) in many countries and regions, widely used in fields directly related to human health, such as food, pharmaceuticals, and cosmetics. Under normal use conditions, it is non-flammable (flash point > 149 °C), but it should be noted that it has mild irritant effects on the skin and eyes. It is recommended to wear appropriate personal protective equipment during handling.

Technical Parameters

Application Suggestions

Thanks to its versatile interfacial properties, Span S-60 finds wide application across multiple industries:

• Cosmetics and Personal Care: Used as a primary or auxiliary emulsifier in creams, lotions, sunscreens, etc., imparting a fine texture and good spreadability to products, while the protective film formed can provide certain moisturizing effects.
• Food Industry: Used in high-fat foods such as margarine, ice cream, pastries, and chocolate as an emulsifier and stabilizer to prevent oil separation, improve texture, and extend shelf life.
• Pharmaceuticals and Health Products: Used as an important component of suppository bases and drug carriers, facilitating uniform drug dispersion and controlled release, improving stability and bioavailability of oral and topical formulations.
• Textile Industry: Used as a key component of spinning oils for synthetic fibers, providing smoothness, cohesion, and antistatic properties.
• Agricultural Chemicals: Used as an emulsifier in pesticide emulsifiable concentrate formulations, helping the active ingredients form stable emulsions upon dilution.
• Plastics Industry: Used as an anti-fogging and antistatic internal additive in polyolefin films.
• Coatings and Inks: Used as a wetting and dispersing agent for pigments, preventing agglomeration, floating, and flooding.

Precautions

• Storage Conditions: Store in a cool, dry, well-ventilated place, recommended temperature below 35°C, away from direct sunlight and strong oxidizing agents. May solidify at low temperatures; bring to room temperature before use.
• Personal Protection: It is recommended to wear chemical protective gloves and safety goggles during handling. If dust is generated and ventilation is insufficient, wear a particulate respirator.
• Compounding Suggestions: Usually compounded with the Tween series (e.g., Tween-60) to obtain a wider range of HLB values and more stable emulsification effects. The specific compounding ratio should be determined based on the oil phase type and target system.