Diethanolamine and Diethanolamine Salts

Safety Information

Expert Panel for Cosmetic Ingredient Safety

The safety of DEA and DEA-containing salts have been assessed several times by the Expert Panel for Cosmetic Ingredient Safety (formerly the Cosmetic Ingredient Review Expert Panel).

In 1983, the Expert Panel evaluated the available scientific data. It concluded that DEA was safe in cosmetics and personal care products designed for brief use, followed by thorough rinsing from the skin’s surface. In products intended for prolonged contact with skin, the concentration of DEA should not exceed 5%. Additionally, DEA should not be used in products that contain N-nitrosating agents to prevent the formation of possibly carcinogenic (i.e., cancer-causing) nitrosamines

In 2011, the Expert Panel reviewed the scientific data supporting the safety of DEA and 16 DEA salt ingredients and concluded that they are safe in the present practices of use and concentration when formulated to be non-irritating to skin. However, the Expert Panel cautioned that these ingredients should not be used in cosmetics products in which N-nitroso compounds can be formed. This opinion superseded the one from 1983.

Diethanolamine (DEA) DEA-stearate DEA-laureth sulate
Diethanolamine bisulfate* DEA-C12-13 alkyl sulfate* DEA-lauryl sulfate
DEA-cocoamphodipropionate* DEA-C12-13 pareth-3 sulfate* DEA-methyl myristate sulfonate*
DEA-isostearate* DEA-C12-15 alkyl sulfate * DEA-myreth sulfate*
DEA-linoleate DEA-cetyl sulfate* DEA-myristyl sulfate*
DEA-myristate* DEA-dodecylbenzesulfonate*

*Ingredients not currently in use. If these ingredients are used in the future, the expectation is that they would be used in product categories and at concentrations comparable to others in this group.

The Expert Panel noted that DEA salt ingredients may contain small amounts of DEA as a manufacturing impurity and expressed concern about the potential conversion of the residual DEA in the presence of N-nitrosating agents into carcinogenic (i.e., cancer-causing) N-nitrosamines. Therefore, the Expert Panel recommended that DEA and its salts should not be used in formulations when N-nitrosating agents are present.  

The Expert Panel also discussed the 1998 dermal carcinogenicity studies conducted on DEA by the U.S. National Toxicology Program (NTP). The study found an association between the topical application of DEA and certain DEA-related ingredients and cancer in laboratory animals. For DEA-related ingredients, the NTP study suggested that the carcinogenic response was linked to possible residual levels of DEA. 

Given the non-genotoxic mechanism of action postulated for the DEA-induced carcinogenicity, the fact that DEA is only weakly absorbed through human skin, and the use concentration of DEA in products is relatively low (≤0.06% in leave-on products), the Expert Panel concluded that the NTP study results had little relevance on the safety of DEA used in personal care products.

IARC Review

The International Agency for Research on Cancer (IARC), which is part of the World Health Organization, also assessed the possible carcinogenicity of DEA in 2012, concluding there is “inadequate evidence” in humans for the carcinogenicity of DEA and there is “sufficient evidence” in experimental animals. The overall conclusion was that DEA is “possibly carcinogenic” to humans (IACR carcinogenicity Group 2B).

FDA Review

Based on these thorough assessments, the FDA’s position is that “[t]he NTP study did not establish a link between DEA and the risk of cancer in humans,” and that “FDA believes that at the present time there is no reason for consumers to be alarmed based on the use of these substances in cosmetics.”

The agency has advised that consumers should review the ingredient label if they want to avoid DEA or DEA-related ingredients.

DEA and its salts (i.e., the DEA salt ingredients reviewed on this webpage) are on the EU’s list of banned substances in cosmetics products (Annex II, entry 411 of the Cosmetics Regulation). The basis for this ban is the concern for potential conversion of DEA to carcinogenic nitrosamines.

Diethanolamine and Diethanolamine Salts

What Is It?

Diethanolamine (DEA) is a white crystalline solid at room temperature, that changes into a colorless viscous liquid with an ammonia-like odor at temperatures above 28C. DEA is primarily used as a DEA salt, which is very stable and does not freely dissociate in water.

Why Is It Used?

DEA is rarely used in products. DEA salts function as surfactants, emulsifying agents, viscosity-increasing agents, hair or skin conditioning agents, foam boosters, or antistatic agents.

Scientific Facts

As with any chemical reaction, there may be unavoidable small amounts of starting materials (in this case, DEA) carried into the final product via the DEA salt ingredients. These low residual levels do not impact the use or performance of these ingredients and are controlled to safe levels during manufacture. 

DEA and DEA-derivatives are approved for use in other products, primarily food packaging.