Glycol – types, action, properties and application

Proven content

Glycol, and more precisely glycols, are organic chemical compounds belonging to the group of dihydroxy alcohols, i.e. diols. There are several types of glycols that differ in the number of carbon and hydrogen atoms. Glycols are used in industry, processing, pharmacy and cosmetics. What are glycols? Are they safe for health?

Glycol – types

There are several types of glycols. They differ not only in their chemical structure, but also in application and toxicity. Here are the types of glycol:

1. ethylene glycol (1,2 – ethanediol),
2. propylene glycol (1,2 – propanediol),
3. diethylene glycol (DEG),
4. monoethylene glycol (MEG).

Ethylene glycol – properties and application

Ethylene glycol is an alcohol that contains two hydroxyl groups in its molecule, hence its systematic name: 1,2 – ethanediol. It is a colorless and odorless liquid with a sweetish odor.

Ethylene glycol is a chemical substance commonly used in industry, it is mainly used in refrigeration. Ethylene glycol prevents the car engine from freezing in winter and acts as a coolant during high temperatures in summer. It is used as industrial coolants for gas compressors, heating systems, ventilation and air conditioning.

Ethylene glycol is also used as a raw material in the production of a wide variety of products including:

1. polyester fibers for clothes, upholstery, carpets and pillows,
2. glass fibers used in products such as water skis, tubs and bowling balls
3. polyethylene terephthalate resins used in packaging films and bottles. 

Many of these products are energy-efficient and cost-effective, and are also recyclable.

Ethylene glycol – harmful to humans

There is ethylene glycol toxic to humanswhich may endanger his health and even life. Human organism it is absorbed through the skin, respiratory tract and from the gastrointestinal tract. After the consumption of ethylene glycol, symptoms similar to those appear in the initial stage intoxicationand then (after a few or several hours) metabolic acidosis occurs. If the glycol is heated, the vapor generated can lead to loss of consciousnesswhile in low concentrations it causes irritation of the nose and throat and headaches. It also acts as a depressant on the central nervous system. It is irritating to the mucous membranes of the nose and conjunctiva.

Also read: Ethylene glycol poisoning

Propylene glycol – properties and application

Propylene glycol is an oily, colorless, odorless liquid with a slightly sweet taste and high viscosity. It is also a hygroscopic substance: it is soluble in acetone, chloroform and water.

Propylene glycol is a substance commonly used as food additive or ingredient in many cosmetic and hygiene products. Propylene glycol is mainly used as a food processing aid, improving its texture, appearance, taste and shelf life. In addition, propylene glycol can be used in food as follows:

1. helps prevent food ingredients from sticking to each other and forming lumps e.g. in instant products, dried soups and ready-made grated cheese,
2. extends shelf life of the foodby protecting it from deterioration caused by oxygen
3. dissolves other food additives or nutrients used in processing, such as dyes or antioxidants,
4. zprevents the separation of food ingredients such as oil and vinegar in the salad dressing.
5. helps keep food at a constant level of moisture and prevents drying out, e.g. various types of foam, coconut flakes or nuts,
6. it is used to increase the attractiveness of food, e.g. it helps to maintain greater clarity of liquids,
7. it is used to thicken food,
8. can change the look or taste of food.

Due to its chemical properties, it is also found in a wide range of hygiene and cosmetic products. In addition, it is used in industrial products such as paints, e-cigarettes, thawing agents and refrigeration. Propylene glycol is one of the most commonly used ingredients in cosmetics and personal care products, including face cleansing gels, moisturizing creams, bath soaps, shampoos and conditioners, deodorants, and shaving preparations.

This type of glycol is also added to the preparation of drugs, where it serves as a so-called. excipient – otherwise a fluid in which the active ingredient of the drug can be distributed. At the same time, it does not affect the condition of our body.

See also: Are e – cigarettes harmful?

Propylene glycol in cosmetics

Propylene glycol has many functions and it is used in many skin care products due to its versatility. Here are its main functions and use in cosmetics:

1. is an effective means of maintaining moisture and hydration, prevents water loss through the skin,
2. increases the absorption of active ingredients by the skin, penetrates into the deep layers of the skin,
3. has softening properties,
4. is an excellent solubilizer of other ingredients,
5. facilitates the application of creams.

Read: Skin defect and allergy

Propylene glycol and the risk of allergies

Propylene glycol, despite being widely used and very useful, has raised concerns about its safety in recent years. The US Food and Drug Administration (FDA) has stated that propylene glycol is “Generally considered safe”, However, in the scientific literature cases of its side effects have been reported, including: irritation of the eyes and skin, allergies and contact urticaria.

However, propylene glycol is considered to be safe to use. Of course, some people who are allergic to it may develop an allergic reaction, namely a skin reaction due to contact allergy. Then, you should discontinue all products containing propylene glycol.

Diethylene glycol – properties and application

Diethylene glycol is a colorless, clear and odorless liquid with a slightly sweet taste. It is hygroscopic with low variability and low viscosity. It is an excellent solvent for water-insoluble chemicals and drugs.

Like other types of glycol, it is used in industry, including the production of resins, furniture production, shoe polishes, plasterboard, emulsifiers, cooling and de-icing fluids and cosmetics.

The effects of diethylene glycol consumption may be: drowsiness, digestive tract disorder and muscle weakness. Ingestion of large amounts may cause kidney and liver disease and be fatal.

Monoethylene glycol – properties and application

Monoethylene glycol is a colorless, odorless, syrupy liquid with a sweetish aftertaste. It is miscible with water, alcohols and many other organic compounds.

It is an essential component for the production of polyester fibers and films and for engine cooling. It is an important ingredient in the production of such end products as: clothing (e.g. polyester fabrics and fleece) and other textile products (e.g. upholstery, carpets and pillows), packaging (e.g. food containers) and dishes.

Direct contact with this glycol can cause eye irritation, tearing, eye pain or visual disturbances. Skin contact may be slightly irritating to the skin. The substance is not allergenic. Its consumption may cause nausea and vomiting, metabolic acidosis, depression of the central nervous system, cardiovascular effects, tachycardia, hypertension, congestive heart failure, adult respiratory distress syndrome, and sometimes fatal kidney damage.