What Is Diethylene Glycol Diisononanoate?
Diethylene Glycol Diisononanoate is a synthetic ester created by combining diethylene glycol, a small water-binding molecule, with isononanoic acid, a fatty acid derived from petrochemical or plant-based sources. The result is a clear lightweight liquid often described chemically as oxydiethylene dinonanoate. It first appeared in cosmetic labs in the late 1970s when formulators needed an alternative to heavier oils that could soften skin without leaving a greasy afterfeel. To make it, manufacturers react diethylene glycol with two equivalents of isononanoic acid under controlled heat and vacuum, then purify the product to remove any residual acids or solvents. Because it offers slip, flexibility and a pleasant skin feel, the ingredient shows up in a variety of products including facial moisturizers, anti-aging creams, lightweight body lotions, hair conditioners, styling creams, sunscreens and color cosmetics like foundations or lipsticks.
Diethylene Glycol Diisononanoate’s Cosmetic Benefits/Uses
This versatile ester supports both skin and hair care formulas in several ways.
- Hair conditioning – coats the hair shaft to smooth cuticles, reduce frizz and improve combability for a softer healthier appearance
- Plasticiser – adds flexibility to solid or semi-solid products such as sticks and pressed powders preventing cracking and improving spreadability
- Skin conditioning – forms a light emollient film that helps skin feel supple and velvety enhancing overall comfort
- Emollient – fills microscopic gaps between skin cells to reduce transepidermal water loss delivering a lightweight non-oily moisturising effect
Who Can Use Diethylene Glycol Diisononanoate
Because it is a lightweight non greasy ester that offers moisture without heaviness, Diethylene Glycol Diisononanoate suits most skin types including dry, normal, combination and oily. Sensitive or easily irritated skin usually tolerates it well since it is fragrance free and has a low molecular weight that sits on the surface rather than penetrating deeply. Acne-prone individuals may also find it compatible as it ranks low on the comedogenic scale and does not clog pores.
The ingredient is produced from diethylene glycol and isononanoic acid that are sourced from petrochemicals or occasionally plant feedstocks, not animals, so it is generally considered suitable for vegans and vegetarians. Always verify the full product formula to be sure no other animal-derived components are included.
No specific warnings exist for women who are pregnant or breastfeeding, and the ingredient is not known to absorb in amounts that would pose a risk. That said this is not medical advice; anyone expecting or nursing should show their healthcare provider any cosmetic product they plan to use to confirm personal safety.
Diethylene Glycol Diisononanoate does not increase photosensitivity, so there is no added risk of sunburn or pigmentation changes when it is applied. It also plays well with most other common cosmetic ingredients making formulation conflicts unlikely.
Potential Side Effects/Adverse Reactions
Responses to topical Diethylene Glycol Diisononanoate differ from person to person. The following is a list of potential side effects that can occur, though most users will not experience them when the ingredient has been properly formulated and used as directed.
- Mild skin irritation such as redness stinging or itching in very sensitive individuals
- Contact dermatitis in the rare event of an allergy to the ester or trace impurities
- Eye irritation if the product accidentally gets into the eyes, leading to tearing or burning
- Scalp buildup when used in hair care for extended periods without thorough cleansing which can make hair feel heavy or dull
If any discomfort or adverse effect occurs stop using the product and consult a medical professional for guidance.
Comedogenic Rating
Rating: 1 out of 5. Diethylene Glycol Diisononanoate is a small lightweight ester that sits on the skin surface without forming a heavy occlusive film, so it rarely traps oil or debris in pores. Its molecular structure lacks long straight fatty chains that typically raise the risk of breakouts, which keeps its comedogenic potential low.
This makes the ingredient generally suitable for people who are prone to acne or frequent breakouts.
Formulas that pair the ester with heavy waxes or butters could increase overall pore clogging potential, so look at the full ingredient list if acne is a concern.
Summary
Diethylene Glycol Diisononanoate works as a hair conditioner, plasticiser, skin conditioner and emollient. It smooths hair cuticles for easier styling, softens pressed powders so they glide on evenly, forms a light moisturising film that leaves skin velvety and fills tiny gaps between skin cells to lessen water loss without greasiness.
The ester is more of a behind the scenes helper than a headline act. It shows up in many modern lightweight creams, lotions and makeup items but is not as widely talked about as jojoba oil or hyaluronic acid.
Overall safety is considered high with minimal irritation reports and a very low comedogenic rating, yet it is always smart to patch test any new product to confirm personal compatibility.