What Is Diethanolamine?
Diethanolamine is an ingredient used in skincare and cosmetic formulations to adjust the pH and improve the stability and lather of a product.
Diethanolamine or DEA is generally used in products such as moisturizers, sunscreens, shampoos, cleaners and conditioners. DEA is rarely used and when it is used it is used in very small quantities to ensure that the product is gentle and non-irritating.
Diethanolamine is a di-alcohol due to the two hydroxyl groups that it has in its molecular structure. As an amine, it is also a weak base. Diethanolamine is used in the production of salt of long-chain fatty acids, allowing hydrating products to be able to foam and lather. There are two other similar ingredients that are used in skincare formulations, triethanolamine and monoethanolamine.
There is some controversy over the use of diethanolamine due to claims that it may be linked with cancer. This claim has been assessed by both the US Food and Drug Administration and the Cosmetic Ingredient Review Expert Panel and both have concluded that there is insufficient evidence to support the claim that diethanolamine is linked to cancer in humans. Diethanolamine is restricted to small concentrations in skincare and cosmetic products and is rarely used.
the good: Diethanolamine helps to improve the foaming abilities and creaminess of products as well as helping to adjust the pH of a formulation.
the not so good: Can be irritating to some skin types.
Who is it for? All skin types except those that have an identified allergy to it.
Synergetic ingredients: Works well with most ingredients
Keep an eye on: Keep an eye out for the other two related ingredients in your formulation, triethanolamine and monoethanolamine.
Why Is Diethanolamine Used?
Diethanolamine is used to improve both the consistency of a product and to adjust the pH, making the product both safer and enjoyable to use.
Diethanolamine is mainly used to improve the foaming or lathering abilities of skincare, hair care and cosmetic formulations. The foaminess of a product is an important part of the formulation process as it helps the product to more effectively lift dirt and oil as well as improve how enjoyable the product is to use.
The pH of a product is one of the most important considerations when formulating. As the skin’s natural pH is around 4.7-5.75, the products that you use on the skin need to sit roughly in that range in order to not irritate or disrupt the skin’s natural barrier.
The skin’s natural barrier consists of oils, ceramides, cholesterol, amino acids and skin cells and helps to protect the skin from moisture loss, irritation, allergens and bacteria. When the skin barrier is disrupted it can cause an irritating rash, breakouts and sensitivity. Disruption of the skin’s natural barrier has been linked to conditions such as dermatitis and eczema. This is why the pH of a product is so important. If a product is too acidic or too basic it can damage the integrity of this barrier.
Diethanolamine, as a base, helps to reduce the effect of acidic ingredients and increase the pH of a product.
Why Is Diethanolamine Controversial?
There are some claims that diethanolamine is linked to cancers in humans. This claim has been tested by the National Toxicology Program as well as the International Agency for Research on Cancer, part of the World Health Organization. Neither study found evidence to suggest that there was a link between cancer and diethanolamine in humans. These findings have led the US Food and Drug Administration to make the determination that diethanolamine is safe in its current indicated uses and that the FDA ‘will advise the industry and the public and will consider its legal options under the authority of the Food, Drug and Cosmetic Act in protecting the health and welfare of consumers.’
Another concern that has been brought up regarding diethanolamine is a study that suggested a link between diethanolamine and brain development in the babies of pregnant mice. As the author of the study said, the research has been reported on disproportionately by the media saying that ‘the finding needs further study and should not cause undue alarm.’ The concentration which diethanolamine is used in is thousands of times lower than that being tested on the mice and human studies don’t indicate this risk.
Is Diethanolamine Safe?
The Cosmetic Ingredient Review Expert Panel, a group responsible for evaluating the safety of skincare and cosmetic ingredients has reviewed the available data on diethanolamine as well as the related triethanolamine and monoethanolamine. Based on this data the determined that diethanolamine is safe for its indicated uses. The Expert Panel suggested that all products that contain diethanolamine should be formulated to be non-irritating. This is due to some studies suggesting that diethanolamine may cause mild to moderate irritation to the skin and eyes. Most jurisdictions limit the concentrations of diethanolamine that can be used in products to reduce the irritation and to minimise any prolonged side effects.