Uses and applications of glycol in industrial products

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

The use of MEG, ethylene glycol, as a raw material occurs primarily in the manufacture of plastics and paints. MPG, monopropylene glycol, exists in two grades that serve different uses: technical MPG and food-grade MPG.

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

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

Choosing the right propylene glycol

There are several propylene glycols depending on the intended use.

View all

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 (PNB).

These glycols are used as solvents and raw materials for parapharmacy, cosmetics, paint manufacturing, and the textile industry. This list is not exhaustive.

The use of MEG (ethylene glycol) as a raw material occurs mainly in the manufacture of plastics and paints. MPG (monopropylene glycol) exists in two grades serving different purposes: technical MPG and food-grade MPG.

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

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

  • Food Grade MPG E1520 20KG Jerry Can
1 5

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

Packaging

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

View full details

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 American health authorities for use in food, medicines, and cosmetics.

However, as with any substance, exposure to high concentrations of MPG can cause adverse effects. Ingestion in large quantities can cause symptoms such as headaches, nausea, and dizziness. It is also possible that some people may be allergic to this substance, although this is rare. As a general rule, normal use of products containing MPG should not present 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 main ingredient in cooling and antifreeze fluids for vehicles. 

MEG is far more toxic to humans and the environment. Ingestion, even in small quantities, can cause serious health effects, ranging from poisoning and narcosis symptoms to potentially fatal damage to the kidneys, heart, and nervous system.

It is therefore very important to avoid any oral contact or prolonged skin contact with MEG. It is also a known irritant and can cause problems if inhaled. Although MEG is an essential chemical in certain industries, it must be handled with the greatest care to avoid dangerous exposures. Products containing MEG must 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 harmful effects on the nervous system, the gastrointestinal system, the kidneys, and other organs. Toxicity varies depending on the type of glycol and the dose of exposure.

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

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

Allergic reactions: Some people may develop a sensitivity or allergy, which can lead to skin reactions, itching, skin rashes, or respiratory symptoms.

Fire and explosion risks: 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 precautionary measures when handling solvent glycols, such as the use of personal protective equipment (gloves, safety glasses, protective clothing), adequate ventilation in work areas, and adherence to good handling and storage practices. It is recommended to consult the safety data sheets of specific products to obtain detailed information on the hazards and safety measures associated with solvent glycols and the raw materials used.

Uses of glycol as antifreeze and heat transfer fluid

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

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

The main uses of MEG:

  1. frost protection – ethylene glycol as a component of antifreeze agents improves heat transfer properties, including lower dynamic viscosity and higher thermal conductivity. It has a higher antifreeze capacity than MPG, meaning it can withstand lower temperatures without freezing. MEG is often used in engine cooling systems, air conditioning 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. protection against corrosion of various engine components and the entire cooling system – this can be achieved through the inclusion of synergistic corrosion inhibitors that protect metals, which are 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

The main uses of MPG:

MPG has several uses as there are two derivatives: technical MPG and food-grade MPG.

Technical MPG is also used as a heat transfer fluid and antifreeze in certain specific cases. Its boiling point is also high, and its freezing point, much lower than that of water, allows efficient heat transfer when used in antifreeze and refrigerant fluids.

Non-toxic to the environment and health, technical MPG as an antifreeze is primarily used in industrial sectors to conduct heat or cold. It is ideal for the manufacture of solar panels or the cooling of tools and products intended for food consumption (beer fermentation tanks, for example).

Arcane Direct offers these concentrated heat transfer fluids (i.e.: MPG molecule, dye, and a corrosion inhibitor), which you can mix with water; or diluted (i.e., pre-diluted with water, the percentage of water depending on the desired freezing point. We offer 3 freezing points).

Use as coolant

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

Which glycol to use as a coolant?
Both MEG and MPG can be used as coolants. They have a few differentiating characteristics that you will find below.

Monoethylene glycol
Freezing point: Lower than that of water

Heat transfer capacity: Better heat transfer capacity

Anti-corrosion properties: more effective

Toxicity: more toxic to health and the environment

Viscosity: lower than MPG

Compatibility with materials: compatible with common engine materials. May damage rubber and plastic type materials

Cost: cheaper than MPG (€3.20/kg)

Monopropylene glycol
Freezing point: Lower than that of water

Heat transfer capacity: Slightly lower than that of MEG

Anti-corrosion properties: less effective

Toxicity: non-toxic

Viscosity: higher

Compatibility with materials: compatible with common engine materials

Cost: more expensive than MEG (€4.80/kg)

Uses of glycol in the synthesis and formulation of industrial chemical products

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 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 can help 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 mixtures of monoethylene glycol (MEG) and monopropylene glycol (MPG). These mixtures 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 prevention of hydrate formation. TEG is also used in the chemical industry for dissolving certain compounds and in other technical applications.

Hexylene Glycol (HG) is an oxygenated solvent containing two alcohol functional groups. It is derived from acetone and is characterized by a relatively slow evaporation rate 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 the reaction of butyl alcohol with ethylene oxide. It is primarily used in the paint and coatings manufacturing industry. This oxygenated solvent appears as a clear liquid with a characteristic ether odor. It is considered a substitute for the 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 readjust the viscosity of fragrances and fix them. It is widely used in ambient perfumery.

Butylene glycol (BG): Butylene glycol is used in cosmetics as a solvent, moisturizing agent, and texturizing agent. It helps keep skin hydrated, improves the diffusion of active ingredients, and provides 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 often used as skin conditioning agents, emulsifiers, and solvents for active ingredients.

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

Butyl Glycom is a glycol ether used in cosmetics, particularly in the manufacture of liquid soaps.

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

E-cigarettes and the food industry

For e-cigarette liquids, food-grade MPG or PG (monopropylene glycol) is the glycol most commonly 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 strict food quality and safety standards, making it a suitable choice for use in food products. It is used as an additive, preservative, and solvent for flavorings.

Inks, paints, printing

Propylene glycol (PG): Propylene glycol is widely used in inks, paints and printing due to its ability to improve viscosity, stability and the application of formulations. It acts as a solvent, humectant and viscosity control agent. PG can also help prevent premature drying of inks 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, facilitating the formation of a uniform film during drying. DEG also improves the stability of formulations and can be used in water-based inks.

Triethylene glycol (TEG): Triethylene glycol is used as a solvent in inks, paints and printing. It can help dissolve pigments and dyes, improve the dispersion and fluidity of inks, and contribute to the stability of formulations.

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, thereby 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 in various industries for their properties as solvents, coolants, humectants, stabilizers and other applications.

Is glycol dangerous?

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

Why is glycol used?

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

Where can glycol be purchased?

Glycol can be purchased from suppliers specializing in chemicals, industrial distributors, online commerce sites, and sometimes directly from manufacturers. It is recommended to seek out reliable suppliers and to comply with the regulations and specific requirements of each country when purchasing glycol.

What is the price of glycol per liter?

The price of glycol can 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.