At a Glance
Glycols are used importantly in personal care products as humectants, solvents, and preservatives. Nevertheless, the key difference between propylene glycol and ethylene glycol is toxicity, use, and safety. Ethylene glycol is toxic and has the major industrial application in antifreeze and solvents, but propylene glycol is safe and of large-scale application in cosmetics and skin care formulations. Knowing the distinctions between these glycols allows formulators to make intelligent decisions when choosing ingredients for their products, both safe and effective.
Introduction
In cosmetic product formulations, glycols are used as active ingredients to enhance texture, moisturization, and preservation. Ethylene glycol and propylene glycol are two glycols that are often compared. Although they appear to be functionally similar, their chemical characteristics and safety profiles are quite different. Ethylene glycol is mostly utilized in industrial processes because of its toxicity, while propylene glycol is most preferred in cosmetics and skincare for its safer profile.
Understanding their differences is essential for formulators to provide product effectiveness, stability, and safety to consumers. The difference between propylene glycol and ethylene glycol in personal care formulations is discussed in this article and assists formulators in making sound decisions.
What Are Glycols? Understanding the Basics
Glycols are a type of organic compound belonging to the alcohol family. They are widely utilized in a variety of industries, including cosmetics, pharmaceuticals, and food. Within this large amalgam of different types of glycol, two of the most commonly mentioned application of personal care are:
- Ethylene Glycol (EG)
- Propylene Glycol (PG)
Besides serving as solvents, humectants, and carriers for the active ingredients, they also differ vastly on the safety and suitability for skincare and cosmetic use.
Ethylene Glycol: Properties and Uses
Ethylene glycol is that artificial organic compound, which plays a very important role among all the industrial applications. It is called a diol, i.e., containing two hydroxyl (-OH) groups, because of which its water solubility remains high. Ethylene glycol is a well-known compound for raising boiling and freezing points in liquids and therefore finds application as an ingredient in antifreeze formulations.
Key Properties of Ethylene Glycol
- Chemical Formula: C₂H₆O₂
- Physical Characteristics: This is a colorless liquid and odorless liquid with a little sweet taste. Its sweet taste can prove particularly dangerous when left unattended, increasing the chances of accidental ingestion among children and pets.
- Solubility: Highly soluble in water, hence a good solvent. This property allows its use in various chemical and industrial applications that require water miscibility.
- Hygroscopic Character: Powerful moisture attracting nature that retains moisture in application and makes it an excellent tool for humidity control in industrial processing and formulations.
- Toxicity: High ingestion or absorption of avert harm is health-threatening, potentially causing kidney failure, metabolic acidosis, and damages to the nervous system. Symptoms of poisoning include dizziness, vomiting, seizures, and possible coma requiring immediate medical attention.
Common Uses of Ethylene Glycol
Due to its unique chemical nature, ethylene glycol is used in huge quantities in various commercial and industrial processes. Some of the uses include:
- Antifreeze and Coolants: EG is a crucial ingredient in most automobile and industrial antifreeze liquids to keep them from freezing at cold temperatures and from overheating during extreme heat. It prevents engine parts from getting corroded and thereby increases the life of automobiles and machinery.
- Industrial Solvents: Employed as a solvent in chemical applications, such as the manufacturing of paints, dyes, and inks. Due to its superior solvent capability, it is well-suited for dissolving and stabilizing many compounds to enhance formulation consistency and performance.
- Textile and Plastic Manufacturing: Pertaining to the manufacture of synthetic fibers and plastics, particular mention is made of the production of polyethylene terephthalate (PET). If not for this, ethylene glycol would not find much of a place in the manufacture of consumer goods since PET is widely used in such products as packaging materials, plastic bottles, and clothing fibers.
- Heat Transfer Fluids: Its application lies in HVAC systems, refrigeration, and thermal energy storage, all owing to its refined nature of heat transfer. This is the reason why even temperature regime control has become important in power, food processing, and chemical industries.
Why Ethylene Glycol is Not Used in Personal Care
Ethylene glycol was well-contended in toxic intoxication and can lead to the severest health hazards when drunk or absorbed severely. Due to the above-mentioned toxicity properties, it is refused to be included in cosmeceuticals, skincare, as well as pharmaceutical products.
Propylene Glycol: Properties and Uses
Propylene glycol is a much safer alternative for widely used personal care products. Although it originates from petroleum, experts view it as non-toxic and perfectly suitable for aesthetic applications. Compared to ethylene glycol, it has far lower toxicity levels, thus making it application-approved for skincare, pharmaceuticals, and even food products. Apart from those, propylene glycol is quite an effective humectant, thus is able to hold moisture in formulation products for better texture or effectiveness.
Key Properties of Propylene Glycol
- Chemical Formula: C₃H₈O₂
- Physical Characteristics: A colorless, odorless, and slightly viscous liquid. Its smooth texture allows it to blend in with formulations effectively thus bringing the quality of its consistent product and application improvement.
- Highly Hygroscopic: A very potent humectant holding moisture from the surrounding atmosphere, in-cap skin care formulations, and hair care formulations. The source supports skin hydration from dryness and irritation.
- FDA GRAS: Recognized as safe for use in cosmetics, pharmaceuticals, and food products, certified safe. Widely used intravenously and orally due to low toxicity and biocompatibility.
Common Uses of Propylene Glycol
Propylene glycol finds applications in general for personal care and cosmetic products to pharmaceuticals, food, and other industrial applications.
- Moisturizers and lotions: Enhance hydration and skin feel for skin care products. It also increases the penetration of active ingredients into the skin, thus increasing their effectiveness.
- Serums and creams: With the good distribution and better absorption of beneficial ingredients in the skin; propylene glycol keeps the formulation from drying out and assures the product remains usable for a longer period of time.
- Deodorants and Shampoos: Helps dissolve active ingredients while having a smooth, non-sticky feel. In shampoos, it inhibits drying and enhances conditioning, thus rendering softer and more manageable hair.
- Medicines and Food Products: It serves as a solvent in oral medications, syrups, and injectable drugs. In food products, it acts as a food additive (E1520), which helps retain moisture in the product and improve texture in baked and dairy products.
Ethylene Glycol vs Propylene Glycol: Differences
Understanding the key distinctions between these two compounds is essential for safe formulation.
| Factor | Ethylene Glycol (EG) | Propylene Glycol (PG) |
| Chemical Formula | C₂H₆O₂ | C₃H₈O₂ |
| Toxicity | Highly toxic | Non-toxic |
| Primary Use | Industrial applications | Cosmetics, food, and pharmaceuticals |
| Water Retention | Strong humectant | Strong humectant |
| FDA Approval | Not approved for skincare | Recognized as safe (GRAS) |
| Personal Care Suitability | Not used in skincare | Widely used in cosmetics |
| Environmental Impact | Toxic and hazardous | Biodegradable and eco-friendly |
Types of Glycol Used in Personal Care
Ethylene glycol as well as propylene glycol and other glycol compounds are used for skincare and cosmetics:-
- Butylene Glycol- is one common humectant that improves skin absorption.
- Pentylene Glycol- Emollient and antimicrobial.
- Caprylyl Glycol- Skin-conditioning benefits.
- Hexylene Glycol- Solubilizing active materials and stabilizing formulations.
Each glycol has unique characteristics that make it important to choose the right one for any formulation.
Also Read: Niacinamide vs Retinol: Choosing the Right Active Ingredients for Skincare Manufacturing
Safety and Regulatory Considerations
Safety is a major consideration that results in the choice between ethylene glycol vs. propylene glycol. If ethylene glycol is considered toxic, then it is not allowed in cosmetics. On the other hand, propylene glycol is FDA-approved, used widely, and safe for topical application. Propylene glycol is allowed in cosmetics in the EU but its concentration levels are regulated. According to the Cosmetic Ingredient Review, propylene glycol is deemed safe for use at certain concentrations.
Choosing the Right Glycol for Personal Care Formulations
Thus, for formulators, the choice of the glycol depends on:
- Safety: Non-toxicity makes propylene glycol the best fit.
- Moisturization: To those whose task it is to hydrate, propylene glycol and butylene glycol serve as effective humectants.
- Texture & Feel: Propylene glycol has a smooth, non-greasy finish.
- Compatibility: Added to their list of all advantages is a good compatibility with lots of emulsifiers and active ingredients used in skin care formulation.
- Regulatory Compliance: Always ensure compliance with regional cosmetic safety regulations.
Final Thoughts: Ethylene Glycol vs Propylene Glycol in Personal Care
Propylene glycol is the right input for cosmetic formulation based on safety, flexibility, and effectiveness. By contrast, ethylene glycol is for the sole purpose of industrial use, never for use in cosmetics.
If looking for propylene glycol or other types of glycol of the highest quality for your personal care formulations, the Elchemy is the partner you can trust for sourcing. Living by safety, innovation, and quality, we supply the best ingredients for your cosmetic formulations.
