Question

How should Span S-40 be stored? What is its shelf life?

Answer
2026-06-06 官方文档 司盘S-40

Span S-40 should be stored in a sealed container in a cool (below 35°C), dry, and well-ventilated environment. Under recommended storage conditions, the typical shelf life is 24 months.

Detailed Description

Span S-40 (sorbitan monopalmitate) is a chemically stable nonionic surfactant that does not polymerize or decompose at room temperature. According to the official safety data sheet from Guoli Chemical, the core storage requirements are cool, dry, sealed, and ventilated. The product is a pale yellow waxy solid (melting point 45~47°C), and the storage temperature must be strictly below 35°C; otherwise, softening and caking may occur, affecting performance.

Regarding shelf life, the product database does not provide an exact expiration date. Based on industry practices for nonionic surfactants and the chemical stability of span products, under sealed original packaging and recommended storage conditions, the typical shelf life is 24 months (2 years). It is recommended to follow the "first-in, first-out" principle and conduct annual re-inspection of key indicators such as appearance and acid value for inventory; if qualified, continued use is acceptable.

The product is packaged in 25 kg woven bags or kraft paper bags. After opening, reseal tightly to prevent moisture absorption. Span S-40 has low hygroscopicity (moisture ≤1.5%), but prolonged exposure to high humidity environments should still be avoided to prevent excessive moisture from affecting emulsification performance.

Technical Parameters

ParameterValue
AppearanceWhite to light yellow waxy solid
Melting Point45~47°C
Moisture≤1.5%
Flash Point>200°C
Active Content≥99%
Chemical StabilityStable at room temperature, avoid strong acids and bases
HygroscopicityLow
Packaging25 kg woven bag/kraft paper bag
Recommended Storage TemperatureBelow 35°C
Shelf Life (Recommended Conditions)24 months (industry general reference value)

Application Recommendations

To ensure stable product performance, it is recommended to follow these storage management measures:

  • Incoming Inspection: Upon receipt, confirm that the packaging is intact and sealed without damage; if damaged, replace the container immediately or prioritize use.
  • Storage Location: Keep away from heat sources, ignition sources, and direct sunlight; pay special attention to warehouse ventilation and cooling in summer.
  • Prohibited Co-storage: Store separately from strong oxidizers, strong acids, and other substances to prevent contact deterioration.
  • Post-opening Management: Reseal the bag immediately after dispensing, keep upright to prevent moisture and foreign objects from entering.
  • Re-inspection Cycle: It is recommended to test acid value (standard ≤8) and moisture (standard ≤1.5%) annually to detect quality changes in a timely manner.

Precautions

Span S-40 is not resistant to strong alkali; avoid contact with strong alkaline substances in storage and use environments. Although the product is practically non-toxic (rat acute oral LD₅₀ >10 g/kg), it is still recommended to wear gloves and protective goggles during handling. If the product shows significant color darkening, unusual odor, or severe caking, discontinue use and contact the supplier for quality confirmation. The above shelf life is a general industry reference value; please refer to the expiration date on the Guoli Chemical factory quality inspection certificate for accuracy.