Question

How to use Polyethylene Glycol (PEG-800) and what is the recommended dosage?

Answer
2026-06-06 官方文档 聚乙二醇PEG-800

Polyethylene Glycol (PEG-800) is a white waxy solid (melting point 28~32°C). Before use, it typically needs to be melted by heating or prepared as an aqueous solution. The specific dosage varies by application area, with industry-recommended range of 1%~30%.

Detailed Description

Polyethylene Glycol (PEG-800) (CAS No.: 25322-68-3) is a high-purity nonionic water-soluble polymer produced by Guoli Chemical. At room temperature, it appears as a white to off-white waxy solid with an active content ≥99%. Due to its low melting point (28~32°C), it usually requires gentle heating to 35~40°C to melt into a colorless viscous liquid before adding to the formulation with stirring. Alternatively, it can be pre-dissolved to a certain concentration as an aqueous solution—PEG-800 is readily soluble in water. It is recommended to slowly add the solid to warm water (40~50°C) while stirring to avoid clumping from a single large addition.

In practice, three typical addition methods can be selected based on process requirements: direct melt addition (suitable for oil-phase systems or processes requiring heating), aqueous solution addition (suitable for water-based formulations, facilitating precise metering), and co-blending and grinding with other components (suitable for solid mixtures or powdered products). The product has good chemical compatibility and can be used with anionic, cationic, and nonionic auxiliaries, maintaining effective performance even in hard water conditions.

It is important to note that PEG-800 is a nonionic surfactant with an HLB value as high as 20, strong hydrophilicity, very low to no foam, surface tension of 55~60 mN/m, and does not form micelles. These characteristics determine its main functions in formulations: solubilization, dispersion, lubrication, moisture retention, and shaping, rather than traditional emulsification or detergency.

Technical Parameters

ParameterSpecification
AppearanceWhite to off-white waxy solid
Melting Point28~32°C
Molecular Weight Range700~900
Hydroxyl Value125~160 mg KOH/g
pH Value (1% aqueous solution)5.0~7.0
Moisture≤1.0%
HLB Value20
Cloud Point (1% aqueous solution)>100°C
Viscosity (100°C)15~20 mm²/s
Flash Point>240°C
Active Content≥99%

Application Recommendations

The following are recommended dosage ranges based on industry practices (Data source: Guoli Chemical product database does not include specific dosages; these are general industry experience references. Actual dosage should be determined through formulation trials):

Application AreaRecommended Dosage (wt%)Usage Method
Pharmaceutical Ointment Base10%~30%Compounded with other PEG series (e.g., PEG-400, PEG-4000), melt-mixed and then cooled to solidify
Suppository Base20%~50%As part of mixed PEG base to adjust melting point and release rate
Skin Care Cream/Lotion (Moisturizer)1%~5%Dissolved in the water phase before addition, providing moisture and smooth skin feel
Cleansing/Makeup Remover Products1%~3%Added as aqueous solution to help reduce irritation
Metalworking Lubricant2%~10%As water-based lubricant additive, directly dissolved in water for use
Rubber Mold Release Agent5%~15%Prepared as aqueous solution or directly applied to mold surface
Textile Sizing Agent1%~5%Dissolved in sizing solution to improve yarn bundling and flexibility
Textile Softening Finish0.5%~3%Used in finishing bath to impart soft hand feel to fabric
Coating Pigment Dispersion0.5%~3% (based on pigment weight)Added during grinding stage to prevent pigment flocculation
Paper Lubrication0.2%~1%Added to pulp to improve paper flexibility and surface smoothness

Precautions

  • Heating Control: For melting, it is recommended to use a water bath or indirect heating method, controlling the temperature at 40~60°C to avoid exceeding the flash point (>240°C) and causing decomposition that generates irritating vapor. Prolonged heating at high temperatures may cause discoloration of the product.
  • Hygroscopicity Management: PEG-800 has some hygroscopicity. After opening, it should be promptly sealed and stored in a cool, dry place (recommended storage temperature ≤40°C) to avoid moisture absorption and clumping or microbial growth.
  • Compatibility Testing: Although the product has broad chemical compatibility, it is recommended to conduct small-scale compatibility tests when compounding with strong oxidizers, certain phenolic compounds, or high-concentration electrolyte systems.
  • Pharmaceutical Grade Use: For use in pharmaceutical preparations, ensure the product grade meets pharmacopoeial standards (e.g., Chinese Pharmacopoeia standards for polyethylene glycol series) and complete corresponding pharmaceutical validation.
  • Safe Handling: The product is practically non-toxic (oral LD50 in rats > 5,000 mg/kg) and non-irritating to skin and eyes. However, it is still recommended to wear protective gloves and safety goggles during handling to avoid prolonged repeated contact. Ensure good ventilation in areas where melting operations are conducted.