Uses and applications of glycol in industrial products

Glycol is a broad family of chemical compounds that plays an essential role across many industrial sectors. The glycol family offers a wide range of applications, from antifreeze to the manufacture of plastics and resins, as well as pharmaceuticals and cosmetics. The derivatives MPG (monopropylene glycol) and MEG (ethylene glycol) are two key members of this family, providing unique properties and essential versatility to many industries.

The use of MEG (ethylene glycol) as a raw material primarily occurs in the manufacturing of plastics and paints. MPG (monopropylene glycol) is available in two grades suited for different applications: technical grade MPG and food grade MPG.

Technical grade MPG is mainly used for the production of plastics, paints, and liquid detergents. Food grade MPG is primarily used in the manufacture of e-liquids for electronic cigarettes, or as an additive for certain flavorings.

Both technical grade MPG and MEG glycols are used as coolants and antifreeze formulations.

Choosing the Right Propylene Glycol

There are several propylene glycols depending on the intended use.

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List of glycols used as industrial solvents:
Diethylene glycol (DEG), Triethylene glycol (TEG), Polyethylene glycol (PEG), Polypropylene glycol (PPG), Dipropylene glycol (DPG), Butyl Glycol (BG), Dipropylene glycol Monomethyl Ether (DPM), Propylene Glycol N-butyl Ether (PNB).

These glycols are used as solvents and raw materials for parapharmaceuticals, cosmetics, paint manufacturing, and the textile industry. This list is non-exhaustive.

The raw material use of MEG (ethylene glycol) occurs mainly in the manufacturing of plastics and paints. MPG (monopropylene glycol) is available in two grades for different uses: technical grade MPG and food grade MPG.

Technical grade MPG is primarily used in the manufacture of plastics, paints, and liquid detergents. Food grade MPG is mainly used in the manufacture of e-liquids for electronic cigarettes, or as an additive for certain flavorings.

Both technical grade MPG and MEG glycols are used as coolants and in antifreeze formulations.

  • Food-grade MPG E1520 Can 5KG
1 5

Food-Grade Monopropylene Glycol (MPG) E1520 CAS No. 57-55-6

Packaging

Food-grade glycols: Food-grade MPG: Used in low doses in the food industry as an additive, flavoring agent, food stabilizer, solvent for flavorings, and e-cigarette liquid. Non-toxic glycol

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Glycol: hazards and toxicity

Common Glycols: MPG and MEG
Monopropylene glycol (MPG) is non-toxic and non-hazardous to the environment. It is approved by European and US health authorities for use in food, pharmaceuticals, and cosmetics.  

However, as with any substance, exposure to high concentrations of MPG can lead to adverse effects. Ingesting large quantities may cause symptoms such as headaches, nausea, and dizziness. It is also possible for some individuals to be allergic to this substance, although this is rare. Generally, standard use of products containing MPG should not pose a significant health risk, but it is always advisable to follow the manufacturer's recommendations regarding use and exposure.

Monoethylene glycol (MEG), also known as ethylene glycol, is commonly used in a variety of industrial and consumer products, notably as the primary ingredient in automotive coolants and antifreeze. 

MEG is significantly more toxic to humans and the environment. Ingestion, even in small amounts, can cause severe health effects ranging from poisoning and narcotic symptoms to potentially fatal damage to the kidneys, heart, and nervous system.

It is therefore very important to avoid any oral or prolonged skin contact with MEG. It is also a known irritant and can cause issues if inhaled. Although MEG is an essential chemical in certain industries, it must be handled with the utmost care to prevent hazardous exposure. Products containing MEG should always be used in accordance with the manufacturer's recommendations and safety data sheets, and must be kept out of reach of children.

Other glycols
Solvent glycols can be toxic if ingested, inhaled, or absorbed through the skin in large quantities. They can cause adverse effects on the nervous system, gastrointestinal system, kidneys, and other organs. Toxicity varies depending on the type of glycol and the level of exposure.

Skin irritation: they can cause skin irritation upon prolonged or repeated contact. This may manifest as redness, itching, rashes, or burning sensations.

Respiratory tract irritation: Inhaling solvent glycol vapors or aerosols can irritate the respiratory tract, causing symptoms such as coughing, throat irritation, shortness of breath, or chest tightness.

Allergic reactions: Some individuals may develop sensitivity or allergies, which can lead to skin reactions, itching, rashes, or respiratory symptoms.

Fire and explosion hazards: Some glycols can be flammable, which may present fire and explosion risks if exposed to heat sources, flames, or sparks.

It is important to take appropriate safety precautions when handling solvent glycols, such as using personal protective equipment (gloves, safety goggles, protective clothing), ensuring adequate ventilation in work areas, and following proper handling and storage practices. It is recommended to consult the safety data sheets (SDS) of specific products for detailed information on the hazards and safety measures associated with the solvent glycols and raw materials used.

Uses of glycol as an antifreeze and heat transfer fluid

One of the main differences between MEG and MPG is their toxicity level.

Use of MEG
Ethylene glycol is primarily used as an antifreeze, engine coolant, and plasticizer. It has a higher boiling point than MPG. It is often the best choice for a heat transfer fluid in systems that have no contact with food, drinking water, or generally with humans or animals.

Main Uses of MEG:

  1. freeze protection – ethylene glycol as a component of antifreeze agents helps improve heat transfer properties, including lower dynamic viscosity and higher thermal conductivity. It has higher antifreeze capacity than MPG, meaning it can withstand lower temperatures without freezing. MEG is commonly used in engine cooling systems, HVAC circuits, and outdoor applications in cold climates.
  2. cavitation protection – the coolant creates an effective protective layer against freezing, boiling, and cavitation, preventing the formation of cavitation pitting
  3. corrosion protection for various engine components and the entire cooling system – this is achieved through synergistic corrosion inhibitors that protect metals commonly used in this type of system. This helps ensure a long service life and high thermal efficiency
  4. protection against the formation and deposition of impurities in the system

Main Uses of MPG:

MPG has multiple applications because two grades exist: technical grade MPG and food grade MPG.

Technical grade MPG is also used as a heat transfer fluid and antifreeze in specific applications. Its high boiling point and significantly lower freezing point compared to water enable efficient heat transfer when used in antifreeze and coolant fluids.

Non-toxic to the environment and health, technical grade MPG as an antifreeze is primarily used in industrial sectors for heating and cooling applications. It is ideal for solar panel manufacturing or cooling equipment and products intended for food consumption (such as beer fermentation tanks).

Arcane Direct offers these concentrated heat transfer fluids (i.e., MPG molecule, dye, and corrosion inhibitor) to mix with water; or ready-to-use diluted fluids (i.e., pre-diluted with water, where the water ratio depends on the desired freezing point. We offer 3 freezing point ratings).

Use as a coolant

Glycol is commonly used as a coolant in several fields, including the automotive industry, aerospace, the chemical industry, winemaking, brewing, and air conditioning. In the automotive industry, glycol is used in engine radiators to absorb excess heat generated by internal combustion. It plays an essential role in maintaining optimal engine operating temperature.

Which glycol should you use as a coolant?
Both MEG and MPG can be used as coolants. They have several key differences outlined below.

Monoethylene glycol
Freezing point: Lower than water

Heat transfer capacity: Higher heat transfer capacity

Anti-corrosion properties: More effective

Toxicity: More toxic to health and the environment

Viscosity: Lower than MPG

Material compatibility: Compatible with standard engine materials. May degrade rubber and plastic materials

Cost: Cheaper than MPG (€3.20 per kg)

Monopropylene glycol
Freezing point: Lower than water

Heat transfer capacity: Slightly lower than MEG

Anti-corrosion properties: Less effective

Toxicity: Non-toxic

Viscosity: Higher

Material compatibility: Compatible with standard engine materials

Cost: More expensive than MEG (€4.80 per kg)

Uses of glycol in the synthesis and formulation of industrial chemicals

Types of glycols by industry:

Emulsifier

For emulsification applications, certain types of glycols are commonly used. Here are some types of glycols that can be used as emulsifiers:

Polyethylene glycol (PEG): Polyethylene glycol is a glycol polymer that can be used as an emulsifier in various formulations. Its ability to reduce the surface tension between water and oil facilitates the formation and stability of emulsions.

Propylene glycol (PG): Propylene glycol can also be used as an emulsifier in certain applications. It helps stabilize emulsions and improve their consistency.

Polypropylene glycols (PPG): Polypropylene glycols, such as polypropylene glycol, help stabilize emulsions and improve their texture.

Ethylene-propylene glycols (EPG): Ethylene-propylene glycols are blends of monoethylene glycol (MEG) and monopropylene glycol (MPG). These blends can be used as emulsifiers to create stable emulsions.

These glycols can be used alone or in combination with other emulsifying or stabilizing agents to achieve the desired emulsification properties.

Solvents

Diethylene glycol (DEG): DEG is used as a solvent in the chemical industry for dissolving resins, dyes, and other chemicals. It is also used in certain pharmaceutical applications and in the natural gas industry.

Triethylene glycol (TEG): TEG is a glycol used as a solvent in various applications. It is commonly used in the natural gas industry for moisture absorption and the prevention of hydrate formation. TEG is also used in the chemical industry for dissolving specific compounds and in other technical applications.

Hexylene Glycol (HG) is an oxygenated solvent containing two alcohol functional groups. It is derived from acetone and characterized by relatively slow evaporation and complete miscibility with water. Hexylene Glycol is commonly used as a solvent and coupling agent, offering a potential alternative to glycol ethers.

Butoxyethanol is a glycol ether produced by reacting butyl alcohol with ethylene oxide. It is mainly used in the paint and coating manufacturing industry. This oxygenated solvent appears as a clear liquid with a characteristic ether odor. It is considered a substitute for PnB solvent and is more volatile than Butyl Diglycol.

Cosmetics 

Dipropylene glycol is an organic solvent used as a moisturizer in cosmetics. It also helps adjust and fix the viscosity of fragrances. It is widely used in home fragrancing.

Butylene glycol (BG): Butylene glycol is used in cosmetics as a solvent, hydrating agent, and texture enhancer. It helps maintain skin hydration, improve active ingredient delivery, and provide a pleasant texture to products.

Polyethylene glycol (PEG): Polyethylene glycols are glycol polymers used in cosmetics for their emollient, solubilizing, and dispersing properties. They are frequently used as skin conditioning agents, emulsifiers, and solvents for active ingredients.

Hexylene glycol (HG) is an oxygenated solvent used as an ingredient in cosmetics and perfumery.

Butyl Glycol is a glycol ether used in cosmetics, particularly in liquid soap manufacturing.

Food grade monopropylene glycol is also used as a raw material in the cosmetics industry.

Electronic Cigarettes and the Food Industry

For e-cigarette liquids, food-grade MPG or PG (monopropylene glycol) is the glycol used, often combined with vegetable glycerin (VG).

In the food industry, food-grade monopropylene glycol (MPG) is often used as a glycol for various applications. Food-grade MPG is specifically manufactured to meet strict food quality and safety standards, making it a suitable choice for use in food products. It is used as an additive, preservative, and flavor solvent.

Inks, Paints, Printing

Propylene glycol (PG): Propylene glycol is widely used in inks, paints, and printing due to its ability to improve the viscosity, stability, and application of formulations. It acts as a solvent, humectant, and viscosity control agent. PG can also help prevent premature ink drying during printing.

Diethylene glycol (DEG): Diethylene glycol is used as a solvent and coalescing agent in paints. It promotes the fusion and spreading of paint particles, thereby facilitating the formation of a uniform film upon drying. DEG also enhances formulation stability and can be used in water-based inks.

Triethylene glycol (TEG): Triethylene glycol is used as a solvent in inks, paints, and printing. It helps dissolve pigments and dyes, improve ink dispersion and flow, and contribute to formulation stability.

Polyethylene glycol (PEG): Polyethylene glycols are used in inks and paints as solvents, viscosity control agents, and dispersing agents. They help improve the dispersion of pigments and fillers, facilitating the homogeneity and stability of formulations.

Frequently asked questions

What is glycol?

Glycol is a family of chemical compounds comprising several types such as monoethylene glycol (MEG), monopropylene glycol (MPG), and other derivatives. Glycols are colorless, viscous liquids used across various industries for their solvent, cooling, humectant, and stabilizing properties, as well as other applications.

 Is glycol dangerous?

Glycols can present certain potential hazards in the event of improper handling or excessive exposure. Certain glycols, such as monoethylene glycol (MEG), can be toxic and irritating to the skin, eyes, and respiratory tract. However, with appropriate precautions and compliance with proper handling practices, risks can be minimized.

Why is glycol used?

Glycol is used for various applications in industries such as automotive, chemical manufacturing, food processing, cosmetics, printing, paints, and more. It can be used as a solvent, humectant, stabilizer, viscosity modifier, antifreeze, food additive, and much more.

Where can you buy glycol?

Glycol can be purchased from chemical suppliers, industrial distributors, e-commerce websites, and sometimes directly from manufacturers. It is recommended to seek reliable suppliers and to comply with country-specific regulations and requirements when purchasing glycol.

What is the price of glycol per liter?

The price of glycol may vary depending on various factors such as the type of glycol, quality, quantity purchased, market conditions, and other specific factors. It is best to contact Arcane Direct to find out the price according to your needs.