Triethanolamine in Skincare

Triethanolamine in Skincare: A Deep Dive into Its Role, Manufacturing, and Effects

What is Triethanolamine?

Triethanolamine (TEA) is a colorless to pale yellow, viscous liquid that serves multiple functions in cosmetic and personal care formulations. It is an organic compound classified as an alkanolamine, containing both amine (-NH2) and alcohol (-OH) functional groups. This combination of properties makes it useful as a pH adjuster, emulsifier, and surfactant in many skincare, haircare, and household products.

Chemically, its molecular formula is C₆H₁₅NO₃, and it is structurally composed of a tertiary amine attached to three ethanol groups. The presence of both hydrophilic (water-attracting) and hydrophobic (oil-attracting) parts in its structure allows TEA to interact with both water and oil, making it highly valuable in emulsions.

How is Triethanolamine Manufactured?

Triethanolamine is synthesized through a reaction between ethylene oxide and ammonia in a controlled industrial process. The reaction produces a mixture of ethanolamines, including monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA). The separation of TEA from these compounds is achieved through distillation.

The basic production process is as follows:

  1. Reaction: Ethylene oxide is combined with aqueous ammonia, leading to the formation of MEA, DEA, and TEA.
  2. Separation and Purification: The mixture undergoes a fractional distillation process, isolating the specific ethanolamine compounds.
  3. Quality Control: The final product is tested for purity, composition, and compliance with regulatory standards before being used in commercial applications.

Industrial TEA can range from highly pure grades used in pharmaceuticals and cosmetics to lower-purity grades used in industrial applications such as metalworking fluids and surfactants.

Why is Triethanolamine Used in Skincare Formulations?

TEA plays a crucial role in cosmetic chemistry due to its ability to adjust pH, stabilize emulsions, and improve product texture. Below are its primary functions in skincare formulations:

  1. pH Balancer

    • Many cosmetic formulations require a pH level that is neither too acidic nor too alkaline to maintain stability and skin compatibility.
    • TEA is a buffering agent, meaning it helps maintain the pH within an optimal range by neutralizing excess acidity in formulations.
    • It is often used in combination with fatty acids, such as stearic acid, to form stable emulsions.

  2. Emulsifier and Surfactant

    • TEA allows oil and water to mix, preventing the separation of ingredients in creams, lotions, and other emulsions.
    • It enhances the spreadability of skincare products, ensuring a uniform texture and application.

  3. Foam Stabilizer

    • In cleansing products like facial washes and shampoos, TEA helps stabilize foam, improving the product’s lathering ability and effectiveness in removing dirt and oil.

  4. Solubilizer

    • TEA aids in dissolving certain ingredients that may otherwise be difficult to incorporate into a formula. This is particularly useful in products containing essential oils or active ingredients that require uniform dispersion.

Where is Triethanolamine Commonly Found?

Triethanolamine is present in various personal care products, including:

  • Facial cleansers and body washes – Helps with foaming and emulsification.
  • Moisturizers and creams – Used to stabilize emulsions.
  • Shampoos and conditioners – Improves product texture and foaming.
  • Sunscreens – Helps blend oil- and water-based ingredients.
  • Eye makeup removers – Assists in breaking down makeup.
  • Hair dyes and bleaching agents – Functions as a pH adjuster to activate certain chemicals.

While TEA itself is not an active skincare ingredient, it plays a supporting role in optimizing the function and feel of formulations.

How Does Triethanolamine Affect Consumers?

Despite its widespread use, TEA is not without concerns. Several factors impact how it affects consumers:

  1. Skin Irritation and Sensitization Risks

    • In higher concentrations, TEA has the potential to cause skin irritation, particularly in individuals with sensitive skin.
    • Prolonged or repeated exposure has been associated with allergic reactions, including redness, itching, and contact dermatitis.
    • Regulatory agencies, such as the European Commission, limit TEA concentration in cosmetics to reduce irritation risks.

  2. Potential Formation of Nitrosamines

    • One of the most debated concerns regarding TEA in cosmetics is its potential to form nitrosamines, which are carcinogenic compounds.
    • Nitrosamines can form when TEA interacts with nitrate or nitrite-containing ingredients or is exposed to high heat over time.
    • While TEA itself is not classified as carcinogenic, the risk of nitrosamine contamination has led to stricter regulatory oversight and formulation restrictions.

  3. Eye and Respiratory Irritation

    • In higher concentrations, TEA may cause irritation if it comes into contact with the eyes. This is particularly relevant in hair dyes and facial cleansers.
    • Aerosolized TEA (as found in some spray formulations) may also contribute to mild respiratory discomfort.

  4. Absorption and Long-Term Exposure

    • TEA is not readily absorbed into the bloodstream in significant amounts through topical application. However, long-term exposure may still lead to cumulative effects, particularly if present in multiple daily-use products.
    • Studies on chronic exposure suggest that repeated high doses in animal models can lead to liver and kidney changes, though the relevance of these findings to human use is still debated.

Regulatory Status of Triethanolamine

The use of TEA in cosmetics is subject to regulations worldwide.

  • European Union: TEA and its derivatives are allowed but with concentration limits, and they must not be used in conjunction with nitrosating agents.
  • United States (FDA): TEA is permitted in cosmetic formulations but must comply with safety standards.
  • Japan and Canada: TEA use is monitored, and formulations must be tested for nitrosamine contamination.

Should Consumers Avoid Triethanolamine?

The decision to avoid TEA in skincare products depends on individual sensitivity and risk tolerance. While TEA is generally considered safe at regulated concentrations, some consumers prefer to avoid it due to concerns over nitrosamine formation and potential irritation.

Those with sensitive skin, allergies, or a preference for natural formulations may choose alternatives such as:

  • Sodium bicarbonate (baking soda) – A natural pH adjuster.
  • Xanthan gum and lecithin – Alternative emulsifiers.
  • Decyl glucoside and coco-glucoside – Mild surfactants derived from natural sources.

Takeaway:

Triethanolamine is a widely used cosmetic ingredient that serves essential functions in stabilizing formulations, adjusting pH, and enhancing product texture. However, its potential for skin irritation and nitrosamine formation has led to scrutiny and regulatory oversight. While TEA is not inherently dangerous when used in compliance with safety standards, it is not a necessary ingredient for effective skincare.

For consumers concerned about ingredient safety, reviewing product labels and opting for alternatives can help minimize exposure. As the skincare industry continues to evolve, brands are increasingly formulating products with natural and less controversial emulsifiers and pH adjusters.