How should polyethylene glycol PEG-400 be stored? What is its shelf life?

Polyethylene glycol PEG-400 must be stored sealed, with temperature control, and protected from moisture. Under proper conditions, the shelf life is typically 2 years.

Detailed Description

Polyethylene glycol PEG-400 (Guoli Chemical product) is a chemically stable non-ionic surfactant. However, due to the presence of hydroxyl and ether bonds in its molecular structure, it has strong hygroscopicity. Prolonged exposure to air will cause it to absorb moisture, leading to quality degradation. Therefore, the core of storage is "sealing and moisture prevention" together with "temperature control." Additionally, although PEG-400 is not flammable (high flash point), it should still be kept away from open flames and strong oxidizing agents to ensure absolute safety.

Regarding shelf life, when stored under recommended conditions in its unopened original packaging, the product is typically stable for 24 months (2 years) from the date of manufacture. After the expiration date, it is not necessarily unusable, but it is recommended to recheck key indicators (such as moisture content, viscosity, pH value, and hydroxyl value) before use. If they meet the standards, it can still be used.

Storage Condition Guidelines (Based on Guoli Chemical Database)

To ensure stable product performance, please strictly adhere to the following storage requirements:

• Keep sealed: The container must always be kept sealed. After use, close it immediately to prevent moisture absorption.
• Temperature control: The storage temperature should be strictly controlled between 5°C and 30°C. Too low temperature may cause the liquid to solidify (freezing point approximately 4-8°C), affecting usage; too high temperature may accelerate deepening of the product color.
• Ventilated and cool: Store in a dry, cool, and well-ventilated warehouse, away from direct sunlight.
• Keep away from heat sources: Despite its open cup flash point ≥200°C, keep it away from heat, sparks, and open flames.
• Isolate storage: Must be stored separately from strong oxidizing agents, strong acids and other incompatible substances to prevent dangerous reactions.

Technical Parameters

The following are key technical indicators related to product stability and storage:

Application Recommendations

Whether used in pharmaceutical preparations, daily chemical care, or industrial processing, if the product has been opened for a long time or the storage environment is highly humid, it is recommended to perform a simple appearance and viscosity check before feeding. If the product becomes turbid, layered, or develops sediment, it usually indicates moisture absorption or contamination and should not be used further. For high-demand injection-grade applications, it is not recommended to use beyond the expiration date.

Precautions

• Anti-solidification treatment: If the storage temperature in winter falls below the freezing point (approx. 4-8°C), PEG-400 may solidify into a waxy solid. This is a physical change and does not affect product quality. It can be melted by raising the ambient temperature (not exceeding 50°C) or using a warm water bath to slowly liquefy, then stirring evenly for normal use.
• Avoid inhalation: When heating for extended periods, ensure ventilation to reduce inhalation of vapor or mist.
• After opening shelf life: The original shelf life refers to unopened state. Once opened, the product should be used as soon as possible to prevent reverse contamination by moisture and impurities from the air.