Used in cosmetics (including skin cleansers, eye gels, moisturizers, shampoos, etc.) as an emulsifier, humectant, moisturizer, thickener, and pH balancer. In cosmetic formulations, it is used to neutralize fatty acids to form soaps and to neutralize sulfated fatty acids to form amine salts. Triethanolamine is a commonly used emulsifier in cream preparations. Cream products emulsified with triethanolamine have a fine texture and a bright white appearance. Additionally, the colloidal phase formed by triethanolamine with higher fatty acids or higher fatty alcohols exhibits good stability, resulting in stable product quality and a high tolerance for additional ingredients. Triethanolamine is a common neutralizing agent for acidic polymer gels such as Carbomer. By neutralizing the carboxyl groups of Carbomer, triethanolamine forms a stable polymer structure, achieving thickening and moisturizing effects.

Adding triethanolamine to liquid detergents improves the removal of oily stains, particularly non-polar sebum, while enhancing detergency by increasing alkalinity. It also exhibits excellent compatibility.

Used as a curing agent for epoxy resins, with a reference dosage of 12-15 parts (by mass). Curing conditions are 80°C/4h or 120°C/2h. It can also be used as a vulcanization activator for natural and synthetic rubbers, a rubber polymerization activator, and as a lubricant and anti-corrosion additive. The long-chain fatty acid salts of triethanolamine are nearly neutral and can be used as emulsifiers for oils and waxes.

Used as a complexing agent for aluminum ions in solutions. This reaction is typically employed to "mask" specific ions in the solution (preventing them from participating in the titration) before performing complexometric titration with another chelating agent (such as EDTA, which forms stable complexes with most metal ions).