Polyethylene Glycol 4000

CAS Number:

25322-68-3

Chemical / IUPAC Name:

Polyethylene Glycol 4000

INCI Name:

 PEG-75 (approximate, varies by manufacturer) . Also referred to as PEG-90 by some suppliers

EC Number:

500-038-2 (for PEG with n=~4000)

Molecular Formula:

H(OCH2CH2)nOH, where n is approximately 70-75

Molecular Weight:

Average 3,500 – 4,500 g/mol (typically ~4000)

Other Names:

PEG 4000, Macrogol 4000, Poly(oxy-1,2-ethanediyl), α-hydro-ω-hydroxy- (average MW 4000)

Uses:

PEG-4000 is a medium-to-high molecular weight, water-soluble polymer. It appears as white to off-white waxy flakes, granules, or powder. It is valued for its binding, lubricating, and consistency-giving properties

 

· Personal Care & Cosmetics: Used in creams, lotions, lipsticks, deodorant sticks, and hair care products as a humectant, binder, and viscosity modifier . It helps maintain moisture and improves product texture .

· Pharmaceuticals: Widely used as a base for ointments and suppositories, a binder in tablet formulations, a lubricant for pills, and a plasticizer in film coatings .

· Industrial Applications: Functions as a mold release agent and lubricant in rubber and plastics processing, an extrusion aid for PVC, and a dispersing aid for color concentrates .

· Biotechnology & Laboratory: Used for protein fractionation, virus precipitation, and as a reagent in cell hybridization and DNA transformation experiments .

· Detergents & Cleaners: Acts as a binder in solid detergent formulations and tablets .

Origin

PEG-4000 is a synthetic polymer produced by the polymerization of ethylene oxide . The "4000" designation refers to its average molecular weight, indicating it is composed of approximately 70-75 repeating ethylene glycol units.

What does PEG-4000 do in a formulation?

  • Binder: Helps hold ingredients together in solid forms like tablets, detergent cubes, and pressed powders .
  • Lubricant: Reduces friction, provides smoothness, and acts as a mold release agent .
  • Humectant: Attracts and retains moisture in cosmetic and personal care formulations .
  • Viscosity Modifier / Thickener: Increases and controls the thickness of aqueous systems .
  • Plasticizer: Imparts flexibility to films and coatings .
  • Carrier / Base: Serves as a water-soluble base for ointments, suppositories, and other pharmaceutical preparations .
  • Solubilizer: Enhances the solubility of poorly soluble substances in aqueous media .

Safety Profile:

· General Hazard Classification: Characterized by less toxicity and less skin irritation . Classified as non-hazardous according to GHS regulations . No harmful effect on health when used properly .

· Toxicity: Low acute toxicity. Oral LD50 (rat) > 50 g/kg (for similar molecular weight PEGs) . Low immunogenic and biocompatible .

· Irritation & Sensitization: Generally regarded as non-irritating and non-sensitizing to skin and eyes. There is no damage in case of contact with skin or lips .

· Biodegradability: Rate of biodegradation decreases with increasing molecular weight. Lower molecular weight PEGs are more readily biodegradable.

· Purity Concern: As an ethoxylated ingredient, manufacturing processes should control potential impurities like 1,4-dioxane or ethylene oxide to ensure high-quality, safe products.

· Environmental: Water hazard class may vary by jurisdiction; not considered acutely hazardous to aquatic life at typical concentrations.

· Regulatory Status: Approved for use in food, cosmetics, and pharmaceuticals worldwide. Meets various pharmacopoeia standards (USP, Ph.Eur.).

Technical profile:

PropertyValues
AppearanceWhite to off-white waxy flakes, granules, or powder
OdorOdorless or slightly characteristic
Hydroxyl Number30 – 36 mg KOH/g
pH (5% solution)4.0 – 8.0
Water Content≤ 1.0%
Acid Value< 0.05 – 5.0 mg KOH/g (varies by grade)
Melting Point54 – 65°C (129-149°F) - Range varies by supplier and exact grade
Density1.20 – 1.21 g/cm³ at 25°C (solid)
Bulk Density400 – 500 kg/m³
Viscosity (at 100°C)75 – 110 mm²/s (cSt)
Flash Point> 171 – 246°C (> 340-475°F) - Closed cup
Boiling Point> 300°C (> 572°F)
Vapor Pressure< 0.01 hPa at 20°C
SolubilitySoluble in water, ethanol, and isopropyl alcohol; insoluble in aliphatic hydrocarbons
Recommended Use Level1 – 15% in cosmetic and pharmaceutical formulations, depending on application.