What Are TEA, DEA, and MEA?

TEA (Triethanolamine), DEA (Diethanolamine), and MEA (Monoethanolamine) are ammonia-derived organic compounds known as alkanolamines. These multi-functional ingredients are used in both industrial and cosmetic formulations.

Uses in cosmetics and skincare include:

• pH adjusters and buffering agents
• Surfactants (cleansing and foaming agents)
• Emulsifiers
• Hair and skin conditioning agents

Industrial uses include:

• Herbicides, cement additives, textile processing, cutting fluids, and household cleaning products.

Why Are TEA, DEA, and MEA a Concern?

1. Carcinogenic Risk from Nitrosamine Formation

• TEA and DEA can form N-nitrosodiethanolamine, a Group 2B carcinogen (possibly carcinogenic to humans), when combined with nitrosating agents, either intentionally added or present as contaminants.
• 2023 meta-analysis in Toxics Journal confirmed the carcinogenicity in rodent models, especially with long-term dermal exposure.

2. Skin Irritation and Sensitization

• MEA has the highest sensitizing potential, followed by DEA, and then TEA.
• Reported symptoms include burning, redness, scaling, and itching, particularly in individuals with sensitive skin, eczema, or rosacea.
• A 2021 Contact Dermatitis study highlighted increased allergic contact dermatitis cases linked to MEA-containing emulsifiers.

3. Skin Barrier Disruption

• Newer studies suggest that DEA impairs ceramide synthesis, which compromises the skin’s protective lipid layer, leading to dryness and increased allergen penetration (Archives of Toxicology, 2022).

4. Systemic Toxicity

• Chronic topical application in animal studies has shown evidence of hepatic and renal toxicity.
• A 2023 review in Environmental Health Perspectives reported neurodevelopmental delays and fetal toxicity in mice models exposed to TEA and DEA during pregnancy.

5. Environmental Harm

• These compounds are toxic to aquatic ecosystems and have been flagged by ECHA for bioaccumulative properties.

Should You Avoid TEA, DEA, and MEA in Your Skincare?

Yes. While cosmetic manufacturers often claim these ingredients are “safe in small quantities,” the lack of cumulative exposure regulation, especially in multi-step skincare routines, makes them worth avoiding.

Avoid especially if you:

• Are pregnant or breastfeeding
• Have sensitive, allergy-prone, or compromised skin
• Follow an eco-conscious or clean beauty lifestyle

How to Identify These Ingredients on Labels

Common derivatives to watch out for:

• Triethanolamine (TEA)
• Diethanolamine (DEA)
• Monoethanolamine (MEA)
• Cocamide DEA/MEA
• Lauramide DEA
• TEA-Stearate or TEA-Lauryl Sulfate

Also avoid products with nitrosating agents, such as:

• Nitrates or nitrites
• 2-Bromo-2-nitropropane-1,3-diol
• Formaldehyde donors

Conclusion: Practice Ingredient Vigilance

If you are unsure whether your skincare or haircare products contain these ingredients, use the Dermatocare Reviews database to search by ingredient and find safer alternatives. The platform allows you to filter and compare formulations free from TEA/DEA/MEA and other harmful chemicals.

Until stronger regulatory oversight becomes standard, knowledge, label-reading, and proactive avoidance are your best defense.

References

1. IARC Monographs. Diethanolamine – IARC Summary & Evaluation
2. NTP Toxicology and Carcinogenesis Studies of Diethanolamine (CAS No. 111-42-2) in F344/N Rats and B6C3F1 Mice (Dermal Studies)
3. Skin sensitizing properties of the ethanolamines mono-, di-, and triethanolamine. Data analysis of a multicentre surveillance network (IVDK) and review of the literature
4. ETHANOLAMINE, National Research Council (US) Committee on Toxicology. Washington (DC): National Academies Press (US); 1984.