Diethanolamine and Diethanolamine Salts
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 The Cosmetic Ingredient Review (CIR) was established in 1976 as an independent safety review program for cosmetic ingredients. The CIR Expert Panel consists of independent experts in dermatology, toxicology, pharmacolgy and veterinary medicine. The CIR includes participation by the U.S. Food & Drug Administration and the Consumer Federation of America. 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 This opinion superseded the one from 1983.
|DEA-C12-13 alkyl sulfate*
|DEA-C12-13 pareth-3 sulfate*
|DEA-methyl myristate sulfonate*
|DEA-C12-15 alkyl sulfate *
*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.
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).
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.