Span S-40 (CAS No.: 26266-57-9), also known as sorbitan monopalmitate or Span 40, is a classic nonionic surfactant produced by Hai'an Guoli Chemical Co., Ltd. Its molecular structure is formed by esterification of sorbitan with palmitic acid, conferring excellent lipophilicity and interfacial activity, making it one of the core emulsifiers for preparing water-in-oil (W/O) emulsions.
This product exhibits good chemical stability and broad compatibility, capable of withstanding acidic, alkaline, and hard water environments while maintaining stable emulsifying performance in complex formulation systems. Additionally, Span S-40 can be well compounded with various ionic and nonionic auxiliaries (such as Tween series products) to meet different emulsification needs by adjusting the HLB value, making it an indispensable basic raw material in fine chemical formulations.
In terms of safety, Span S-40 is classified as practically non-toxic. The acute oral LD₅₀ in rats is greater than 10 g/kg, the primary skin irritation index is 0 (non-irritating), and it has no mutagenicity or teratogenicity. It complies with food additive standards such as FDA 21 CFR 172.842 and can be safely used in food, cosmetics, and pharmaceuticals.
| Parameter | Value |
|---|---|
| Chemical Name | Sorbitan monopalmitate |
| CAS No. | 26266-57-9 |
| Product Type | Nonionic surfactant |
| Appearance | Pale yellow waxy solid |
| Emulsion Type | Water-in-oil (W/O) |
| HLB Value | Not available |
| Hydroxyl Value | Not available |
| Saponification Value | Not available |
| Acid Value | Not available |
| Acute Oral Toxicity (LD₅₀) | > 10 g/kg (rat) |
| Skin Irritation | Non-irritating (primary irritation index 0) |
Span S-40 is widely used across six major industries:
When using, it is recommended to compound with hydrophilic emulsifiers (such as Tween series) to adjust the HLB value to the target range. It is recommended to store below 35°C, keep the packaging sealed, and avoid strong oxidizing agents and strong acids.