Three abbreviations on your ingredient list, MEA, DEA, or TEA, represent a class of chemicals that can react with other ingredients to form nitrosamines, which are known carcinogens. Ethanolamines are workhorses in conventional cleaning products. They adjust pH, boost foaming, and help surfactants dissolve grease. They are effective. They are also among the most common causes of occupational skin sensitization in cleaning workers, and the No Nines™ Standard™ excludes them from every product we make.
What are ethanolamines?
Ethanolamines are amino alcohols, compounds that contain both an amine group (nitrogen-based) and one or more hydroxyl groups (alcohol-based). The three primary ethanolamines are distinguished by how many ethanol groups are attached to the nitrogen atom.
Monoethanolamine (MEA) has one ethanol group. It is used primarily as a pH adjuster and as a key ingredient in heavy degreasers and oven cleaners, where its alkalinity helps break down baked-on residue. Diethanolamine (DEA) has two ethanol groups. It functions as a foam booster and emulsifier in detergents, liquid dish soaps, and some personal care products. Triethanolamine (TEA) has three ethanol groups. It is widely used as a pH adjuster and emulsifier in both cleaning products and cosmetics, including lotions, creams, and shaving products.
The abbreviations MEA, DEA, and TEA do not always appear on their own. More commonly, they are embedded in longer compound names that describe a derivative. Cocamide DEA, lauramide DEA, and oleamide DEA are all diethanolamine-based compounds. If you see "DEA" or "TEA" in any part of an ingredient name, the product contains an ethanolamine derivative. These derivatives carry many of the same concerns as the parent compounds, particularly when it comes to nitrosamine formation.
What the research says
The primary concern with ethanolamines is not the compounds themselves in isolation. It is what they can become when they interact with other ingredients in a formulation.
Nitrosamine formation. When diethanolamine or triethanolamine comes into contact with nitrosating agents (compounds that donate a nitroso group), the reaction can produce N-nitrosodiethanolamine (NDELA), a nitrosamine. Nitrosating agents are not rare; they include nitrite preservatives, certain nitrogen-containing compounds, and contaminants that can form during manufacturing or storage. NDELA has been detected in cosmetic products at levels ranging from 1 ng/g to 48,000 ng/g, according to analytical surveys cited in a 2018 risk assessment published in the Journal of Toxicology and Environmental Health.
IARC classifies NDMA and NDEA as Group 2A probable human carcinogens. The U.K. Department for Business, Enterprise and Regulatory Reform has characterized nitrosamines as toxic in more animal species than any other category of chemical carcinogen.
NTP carcinogenicity findings. The National Toxicology Program conducted dermal studies on diethanolamine in F344/N rats and B6C3F1 mice (NTP Technical Report 478). The NTP found "clear evidence of carcinogenic activity" of DEA in mice, based on increased incidences of liver neoplasms in both sexes and renal tubule neoplasms in males. The NTP also found "clear evidence of carcinogenic activity" for cocamide DEA and "some evidence" for lauramide DEA. The proposed mechanism involves DEA's ability to cause choline deficiency, which has been consistently linked to tumor development in the NTP's dose-response data.
CIR Panel findings. The Cosmetic Ingredient Review Expert Panel, the cosmetics industry's self-regulatory body, assessed diethanolamine and its salts and concluded they are safe for use in cosmetics when formulated to be nonirritating, with one important restriction: these ingredients should not be used in products in which N-nitroso compounds can be formed. That restriction acknowledges the nitrosamine risk directly. The challenge is that predicting nitrosamine formation in a finished product depends on the full formulation, storage conditions, and contamination potential, variables that are difficult for consumers to evaluate from a label.
Skin and respiratory sensitization. A multicentre surveillance study conducted by the IVDK (Information Network of Departments of Dermatology) tested 9,602 patients with monoethanolamine and found a 3.8% positive sensitization rate. MEA is recognized as one of the most significant contact allergens in water-based metalworking fluids. A 2014 study published in the International Archives of Occupational and Environmental Health identified ethanolamines as hazardous substances frequently present in professional cleaning products, noting that cleaning workers are at elevated risk for both skin and respiratory sensitization.
Where ethanolamines show up in your home
Ethanolamines are not confined to one product category. Their versatility as pH adjusters, foam boosters, and emulsifiers means they appear across a wide range of household and personal care products.
In cleaning products, you may find them in oven cleaners (MEA is a common active degreasing agent), laundry detergents (DEA derivatives boost foam and help solubilize soil), liquid dish soaps (cocamide DEA is a common foam booster), floor cleaners, bathroom cleaners, and all-purpose sprays. In personal care, they appear in shampoos and conditioners (cocamide DEA and lauramide DEA are frequent ingredients), body washes, shaving creams and gels, lotions and moisturizers, and some cosmetics including foundations and primers where TEA serves as a pH adjuster and emulsifier.
The prevalence is worth noting. A product can contain multiple ethanolamine derivatives simultaneously. A single shampoo might include cocamide DEA as a foam booster, lauramide DEA as a thickener, and TEA as a pH adjuster. Each one is an additional source of potential nitrosamine precursors in the formulation.
What No Nines uses instead
No Nines products contain no MEA, no DEA, no TEA, and no ethanolamine derivatives. We do not use them in any cleaning product or personal care product in the line.
For surface cleaning, our Whole Home HOCl Cleaner uses hypochlorous acid as its active ingredient. HOCl does not require pH-adjusting ethanolamines to function. It works at a mildly acidic to neutral pH range where its antimicrobial activity is strongest, and it breaks down to salt and water after use.
For drain and appliance care, our Sink + Drain Refresher and Washer Refresh address buildup and odor without the alkaline degreasers that rely on MEA. For laundry, our Laundry Rinse replaces the conventional detergent additives, including DEA-based foam boosters, with a simpler chemistry that does not carry the nitrosamine formation risk.
The point is not that ethanolamines are ineffective. They are effective, and their prevalence in conventional products reflects that. The point is that the byproduct risk, specifically nitrosamine formation, is well-documented by the NTP, IARC, and the industry's own review panel. When alternatives exist that provide comparable cleaning performance without that specific risk pathway, we use the alternatives.
The bottom line
Ethanolamines are effective workhorses with problematic byproducts. They adjust pH, boost foam, and help dissolve grease. They also react with common co-ingredients to form nitrosamines, which the IARC classifies as probable human carcinogens. The NTP found clear evidence of carcinogenic activity for DEA and cocamide DEA in animal studies. Even the CIR Panel, which concluded these ingredients can be safe, added the caveat that they should not be used in formulations where nitrosamines can form.
When the cleaning and personal care industries have access to alternative ingredients that perform the same functions without the nitrosamine formation pathway, the choice is straightforward. No Nines made that choice for every product in the line.
This is the fifth in our Nasty Nine series. Read more about formaldehyde releasers (Post 7) or synthetic fragrance (Post 2) in our other posts. To shop cleaning products formulated without ethanolamines, visit our full collection.
