When sourcing glycols for industrial, pharmaceutical, or cosmetic applications, understanding the distinct properties and safety profiles of each is crucial. Among the commonly used glycols, Polyethylene Glycol 300 (PEG 300), Ethylene Glycol (EG), and Propylene Glycol (PG) are frequently considered. As a dedicated manufacturer and supplier of PEG 300, we aim to provide clarity on how these chemicals differ, helping you make informed purchasing decisions.

Polyethylene Glycol 300 (PEG 300)

Properties: PEG 300, with CAS No. 25322-68-3, is a liquid polymer characterized by its high purity (>99%), water solubility, hygroscopicity, and relative inertness. It is considered to have very low toxicity, making it a preferred choice for pharmaceutical excipients, cosmetics, and food additives (though specific grades apply). Its applications range from solvents and humectants to lubricants and chemical intermediates.

Safety Profile: Generally regarded as safe for many applications, particularly when compared to Ethylene Glycol. It is not considered toxic in the same way EG is.

Applications: Pharmaceutical formulations (solvents, humectants), cosmetics, personal care products, lubricants, plasticizers, and as a chemical intermediate.

Ethylene Glycol (EG)

Properties: Ethylene Glycol is a simpler diol, known for its excellent antifreeze properties and its role in producing polyester fibers and resins. It is a colorless, odorless liquid that is highly miscible with water.

Safety Profile: Highly Toxic. Ingestion of EG can lead to severe health consequences, including kidney damage, and is fatal to humans and animals. Its toxicity is significantly higher than that of PEG or PG.

Applications: Primarily used as antifreeze and coolant in automotive systems, as a raw material for PET plastics, and in some industrial heat transfer applications. It is strictly avoided in pharmaceutical and cosmetic products intended for human contact or consumption.

Propylene Glycol (PG)

Properties: Propylene Glycol is another diol, similar in structure to EG but with a methyl group. It is also a colorless, viscous liquid, highly soluble in water, and has a milder sweet taste compared to EG. PG is also hygroscopic.

Safety Profile: Generally considered safe for food, pharmaceutical, and cosmetic use (USP/EP grades). While much safer than EG, some individuals may experience allergic reactions. Its toxicity is significantly lower than EG, but it is still more reactive and less inert than higher molecular weight PEGs.

Applications: Widely used as a solvent and excipient in food, pharmaceuticals (laxatives like MiraLAX), cosmetics, and as a de-icing fluid (less toxic alternative to EG). It's also used in e-cigarettes and as artificial smoke fluid.

Choosing the Right Glycol: Key Considerations

When deciding which glycol to buy, several factors come into play:

  • Application: For pharmaceutical or cosmetic use where direct human contact is involved, PEG 300 and USP-grade PG are the preferred choices due to their safety profiles. EG is strictly prohibited. For antifreeze/coolant, EG is common, while PG is a less toxic alternative.
  • Performance Requirements: PEG 300 offers excellent solvency and humectant properties suitable for formulations. EG excels as an antifreeze due to its freezing point depression capabilities. PG is a versatile all-rounder, often used for its safety and functional properties.
  • Safety and Regulatory Compliance: Always ensure the grade of glycol you procure meets the regulatory requirements for your specific industry (e.g., USP/NF for pharmaceuticals, FCC for food). Our commitment as a manufacturer is to provide compliant, high-purity products.
  • Cost: Generally, EG is the most cost-effective. PG is typically more expensive than EG. PEG prices can vary based on molecular weight and purity, with PEG 300 being competitive for its specific applications. As a direct supplier, we strive to offer optimal pricing.

For your critical formulation needs, particularly in pharmaceuticals and cosmetics, PEG 300 often presents the optimal balance of safety, performance, and cost. We invite you to contact us to learn more about our high-purity PEG 300 and to discuss how we can fulfill your chemical sourcing requirements. Partner with a trusted manufacturer to ensure the quality and success of your products.