What Is Diethylene Glycol?
Diethylene Glycol, often shortened to DEG, is a clear, slightly sweet liquid that belongs to the glycol family of alcohols. Chemically it is known as 2,2′-Oxydiethanol, meaning it is made of two ethylene glycol units joined by an oxygen atom. It is produced by reacting ethylene oxide with water under controlled heat and pressure, then purifying the result to remove excess water and by-products. DEG first gained industrial attention in the 1930s for its ability to dissolve a wide range of substances. Over time manufacturers recognized that the same properties could improve the feel, spread, and fragrance of topical products, so it began showing up in cosmetics.
Today DEG can be found in a variety of formulations such as wipe-off facial masks, lightweight moisturizers, hair styling gels, body sprays, and certain anti-aging serums. Its small molecular size lets it blend smoothly with water and many oils, which helps product developers fine-tune texture and performance.
Diethylene Glycol’s Cosmetic Benefits/Uses
In personal care products Diethylene Glycol serves several roles that support both the formula and the user experience:
- Fragrance/Perfuming: DEG helps dissolve aromatic oils and keeps scent molecules evenly dispersed so the fragrance smells consistent from the first pump to the last drop
- Solvent: It can break down and hold together ingredients that otherwise would not mix, allowing actives, colorants, and preservatives to stay stable in a uniform solution
- Viscosity Controlling: By thinning thick mixtures or slightly thickening watery ones, DEG lets chemists adjust how easily a product spreads on skin or hair improving feel and absorption
Who Can Use Diethylene Glycol
DEG is generally well tolerated by most skin types, including normal, oily, combination and mature skin. Those with very dry or compromised skin barriers should be mindful that its solvent nature can sometimes pull moisture away from the surface, which might leave already parched skin feeling tighter or lightly irritated.
The ingredient is synthetic, manufactured from petroleum-derived ethylene oxide and water, so it contains no animal-based inputs. This makes it suitable for vegans and vegetarians who avoid ingredients of animal origin.
Current safety assessments indicate no special restrictions for pregnant or breastfeeding women when DEG is used at the low levels found in cosmetics. That said, research in these groups is limited so this is not medical advice. Anyone who is pregnant or nursing should clear all skincare products with a qualified healthcare provider to be on the safe side.
Diethylene Glycol is not known to cause photosensitivity, so it does not increase the skin’s tendency to burn in sunlight. It also plays well alongside most common skincare actives, though its ability to enhance solubility can make potent ingredients feel stronger on the skin.
Potential Side Effects/Adverse Reactions
Responses to topical Diethylene Glycol vary from person to person. The points below outline potential side effects, but these outcomes are uncommon when the ingredient is used at cosmetic levels and formulated correctly.
- Transient stinging or mild redness on sensitive or broken skin
- Contact dermatitis or allergic rash in individuals predisposed to glycol sensitivities
- Dryness or tightness if present at higher than recommended concentrations
- Eye irritation if the product migrates into the eye area
- Enhanced penetration of other actives, which can amplify irritation from those actives
If any of these reactions occur stop using the product and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 0 / 5 (non-comedogenic)
Diethylene Glycol is a lightweight, water-miscible liquid that does not form heavy films on the skin or clog pores. Its small molecular size and high solubility mean it is easily rinsed away and does not build up in follicles. Because of this it earns a score of 0.
Suitable for people who are prone to acne or breakouts.
Most published data on pore blockage come from fatty alcohols and heavier glycols, not from DEG, which supports its low rating.
Summary
Diethylene Glycol acts as a fragrance carrier, solvent and viscosity controller. It keeps scent molecules evenly mixed, dissolves ingredients that dislike water and tweaks thickness so products feel smooth and spread well. These traits make it a handy helper ingredient, yet it is not as well known to shoppers as glycerin or propylene glycol because it usually appears at low levels and is listed deep in ingredient lists.
When used at the tiny percentages common in cosmetics current research finds DEG safe for topical use. Serious reactions are rare, though anyone trying a new product should still patch test first to be cautious.