Propylene glycol is a very common chemical used in cosmetics. It is a colourless and odourless liquid with a slightly sweet taste. It contains two alcohol groups and is classified as a diol. A diol is an alcohol with two hydroxyl groups. Propylene glycol is also called 1,2-propanediol.
Propylene glycol is produced in large quantities in chemical plants for the production of polymers. It is used at airports for de-icing and anti-icing of aircrafts. Propylene glycol is also known as an antifreeze for car radiators. Propylene glycol is also used in some oral and intravenous medications. Propylene glycol is such a common chemical that you inevitably encounter it every day without even realizing it. The uses of propylene glycol are such that you would never even think of it as a cosmetic ingredient. Why is such a chemical used in skin care? Read on to learn more about propylene glycol.
Properties of propylene glycol
Propylene glycol has many good properties, and because of that it is such a desirable and versatile chemical. Basically, propylene glycol is a solvent. It helps to dissolve the cosmetic ingredients in the liquid.
It is a viscous, colourless liquid that is almost odourless. However, it has a sweet, very mild taste. Propylene glycol mixes well with many types of liquids, including water. In the European Union, it has an official E-code, food additive number, E-1520. For cosmetics and pharmacology uses, the number is E-490. The vapourability of propylene glycol is weak. It is a humectant, meaning it attracts moisture from the surrounding air. In cosmetics, propylene glycol is used precisely to preserve moisture and to prevent, for example, make-up products from drying out. One of the most important properties of propylene glycol is its ability to remain liquid even in freezing conditions.
What is Propylene Glycol made from?
Propylene glycol is a typical petrochemical product. It has traditionally been produced by hydrating propylene oxide. Propylene oxide, on the other hand, is produced by oxidizing propylene with either ethylene benzene or isobutene.
Use of propylene glycol in cosmetics
Propylene glycol is characterized as a humectant. It is a viscous liquid with low toxicity. It is widely used in shampoos, moisturizers, cleansers, conditioners, deodorants, aftershaves, make-up products and perfumes.
The most important property of propylene glycol is its ability to attract moisture. That is why it is used in all moisturizing products. It is also a popular ingredient in creams that prevent the signs of aging because it is able to retain moisture even on thin skin.
Propylene glycol prevents water from evaporating from the skin. That’s why it’s a popular ingredient in dry skin care kits. It also acts as a skin softener.
Propylene glycol helps the other ingredients of the cosmetic product to penetrate the skin. Most cosmetic substances remain on the surface of the skin because they do not have the ability to penetrate deeper into the skin. Propylene glycol acts as a carrier in the product. It moves the active ingredients deeper into the skin.
Propylene glycol is recommended for acne treatment. It is a mild antimicrobial agent that is believed to soothe irritated skin. Propylene glycol is not greasy at all, so it is considered an effective and safe form of acne treatment.
Propylene glycol is used in cosmetics in preservative systems together with other chemicals.
Is propylene glycol a safe ingredient in cosmetics?
In general, propylene glycol is considered a safe chemical. However, that is not the whole truth. The biggest problem with propylene glycol is the allergic reactions it causes. Propylene glycol causes contact dermatitis in some people. Typical symptoms are redness, itching and small blisters on the skin. The American Contact Dermatis Society named propylene glycol the allergen of the year in 2018. The organization wanted to draw people’s attention to its significant share of allergy-causing factors. Most of the people sensitized to propylene glycol do not realize that they are allergic to this particular chemical.
People with eczema are easily sensitized to propylene glycol
Contact allergies are most typical in people with atopic skin or eczema. People whose skin has been damaged in some ways are also more susceptible to becoming allergic to propylene glycol. Also, people who work with machines and engines are more easily sensitized to propylene glycol. If you have ever been sensitized to this chemical, you should always avoid products containing it. Avoiding can be challenging, as propylene glycol is one of the most common of chemicals, which can be found in cosmetic products as well as in foodstuffs and medicines.
Sensitization to propylene glycol first appears on the skin of the face. After this, the rash easily spreads to other parts of the body. Contact dermatitis can also occur after consuming a product containing propylene glycol. For example, some beers and confectionery products contain propylene glycol as an additive. A very typical reaction caused by propylene glycol is dryness of the scalp, flaking and itching. Shampoos and conditioners often contain propylene glycol.
You should always check the ingredient list of the product you are using. Propylene glycol is often found there. Unfortunately, the industry is always coming up with new names for the same compound.
Here are some aliases for propylene glycol
- 1-2-dihydroxypropane
- 1,2-propanediol
- 2 Hydroxypropyl
- Methyl Glycol
- PPG,
- PPG-3
- PPG-7
- PPG-9
- PPG-12
- PPG-13
- PPG-15
- PPG-16
- PPG-17
- PPG-20
- PPG-26
- PPG-30
- PPG-33
- PPG-34
- PPG-51
- PPG-52
- PPG-69
- Propane 1,2-Diol
- Trimethyl Glycol
Propylene glycol is really hard to avoid
If you are once sensitized to propylene glycol, the only way to avoid symptoms is to avoid it. Sensitized people slowly start to realize how difficult it is. Propylene glycol is such a common chemical that there is simply no way escaping it. It is found in car radiators and heaters, anti-icing in airplanes, most common household cleaners, cosmetics, industrially made cakes and sweets. The situation is made even worse by the fact that propylene glycol has the ability to move environmental toxins deeper into the layers of the skin. When we consider all the harmful chemicals we encounter on a daily basis, this may be an even more dangerous phenomenon than the substance itself.
Today, propylene glycol, like other glycols, is used uncatiously, For example, as a moisturizing agent in cosmetics. Propylene glycol is very cheap and does not stick to the skin like glycerol. The many uses of propylene glycol makes it a very popular raw material in cosmetics. The use of glycols in cosmetics should be limited only to products for which it is difficult to find a safer alternative to glycols. There are many safe moisturizing agents suitable for cosmetics.
Propylene glycol is a petrochemical product
It is not allowed to use any chemicals that are related to petroleum or its derivates in Certified natural cosmetics. Propylene glycol is just such a product. However, nowadays, a plant-based propylene glycol has been produced, which is also permitted in natural cosmetics. This is a bit strange because plant origin does not make the substance any safer.
It is a very synthetic substance that would not exist at all without petroleum. Products made from petroleum, such as petroleum jelly, are unnatural products in skin care. There is nothing in petroleum that the skin needs. Although at first it seems that propylene glycol is good for the skin, what does it do in the long run? Where does this chemical go from the skin? It doesn’t evaporate, it’s absorbed.
What to replace propylene glycol?
Propylene glycol should be avoided whenever possible. In cosmetics, it is surprisingly difficult to avoid it’s use due to the versatility of propylene glycol.
Nowadays, certified natural cosmetics makers also use plant-based propylene glycol. This information was a surprise to me too. In case a chemical substance is made either from plants or petroleum, means both substances could be equally dangerous. However, plant-based propylene glycol is a more sustainable choice than a petroleum-based product.
Propylene glycol is often replaced with other glycols such as pentylene, butylene or caprylyl glycol. The users of pentylene glycol have been observed to sentisize to it. The same phenomenon will certainly be a problem with all solvents. Adding solvents to cosmetics is not necessarily safe. The most sensitive people will react to any new solvents in any case.
Natural plant oils can also penetrate the skin, although not as deeply as solvents. By using the genuinely natural ingredients we can achieve almost the same result without harmful side effects. The sterols and oleic acids contained in vegetable oils are now the subject of research in an attempt to find natural alternatives to solvents. Terpenes and polysaccharides found in plants have also been studied as penetration enhancers.
A good and recommended option is to make at least some of your own cosmetics. Homemade cosmetics are exactly as safe as you want them to be. Natural vegetable oils and genuine hydrolates can be used to make the best cosmetics that do not contain questionable chemicals.
If your skin is sensitized and you do not know how to make cosmetics yourself, switch to cosmetic oils only. For already sensitized skin, the best oil is as clear and filtered as possible.
Are you allergic to propylene glycol?