Triethanolamine (TEA) is a common chemical compound found in a vast number of products people use every day. As a colorless, viscous organic liquid, it is valued by manufacturers for its unique chemical properties. This widespread presence in consumer goods has led to questions regarding its long-term safety profile. Understanding the function of TEA and the regulatory guidelines governing its use is important for assessing the ingredient’s role in modern product formulation.
Defining Triethanolamine and its Primary Purpose
Triethanolamine is chemically categorized as an alkanolamine, meaning it possesses properties of both an amine and an alcohol. It is synthesized through a reaction between ethylene oxide and aqueous ammonia, resulting in a compound with the formula C₆H₁₅NO₃. This structure gives TEA a weak alkaline nature, making it effective for neutralizing acidic ingredients within a formulation.
The primary role of Triethanolamine in consumer products is as a pH adjuster, or alkalizing agent. Many cosmetic and personal care products must maintain a specific pH level to prevent irritation and ensure the stability of other active ingredients. By raising the pH, TEA helps to stabilize the product and make it compatible with the skin’s natural slight acidity. Its second major function is as an emulsifier, necessary for mixing ingredients that naturally separate, such as oils and water. When combined with a fatty acid, TEA forms a soap-like compound that keeps the emulsion uniform, preventing creams and lotions from splitting into layers.
Common Products Containing TEA
Triethanolamine is ubiquitous, appearing across many consumer and industrial sectors due to its dual functionality as a pH neutralizer and an emulsifier. In the realm of personal care, it is a frequent component in leave-on skin products like moisturizers, sunscreens, and anti-aging creams. It is also used extensively in cosmetics such as mascara, foundation, and blush to ensure a stable consistency and even application.
TEA is a common ingredient in many household cleaners, including laundry detergents and all-purpose cleaning sprays, where its emulsifying action helps lift grease and oil. Industrially, its applications include its use as a grinding aid in the manufacture of cement, where it prevents powder particles from sticking together. It is also found in metalworking fluids and coolants, where it acts as a corrosion inhibitor to protect machinery.
Understanding the Safety Concerns
The primary safety concerns surrounding Triethanolamine relate to its concentration and its potential for chemical interaction within a product. In its pure form or at high concentrations, TEA is a mild irritant that can cause skin and eye irritation. This effect increases when the concentration in a product exceeds 5%, which is why limits are placed on its use in personal care items.
A more significant concern is the potential formation of N-nitrosamines, which are compounds classified as probable human carcinogens. While TEA itself is a tertiary amine, commercial grades often contain trace amounts of Diethanolamine (DEA) as a manufacturing impurity. This secondary amine (DEA) can react with N-nitrosating agents, such as certain preservatives like Bronopol, to form the harmful compound N-nitrosodiethanolamine (NDELA). This reaction is more likely to occur under specific conditions, such as high heat or an acidic environment.
Regulatory Oversight and Usage Limits
Regulatory bodies worldwide have implemented controls to mitigate the risks associated with TEA, particularly the potential for nitrosamine formation. The Cosmetic Ingredient Review (CIR) Expert Panel in the United States has deemed TEA safe for use in cosmetic formulations designed for brief contact, such as rinse-off products. For products intended for prolonged contact with the skin, the CIR limits the concentration of TEA to a maximum of 5%.
The European Union’s cosmetics regulations mandate specific requirements to ensure safety. These regulations prohibit the use of TEA in conjunction with N-nitrosating agents, thus eliminating the risk of NDELA formation during storage. The maximum permissible concentration of residual nitrosamines in finished cosmetic products is limited to 50 micrograms per kilogram (50 ppb). Manufacturers must ensure a minimum purity of the raw TEA ingredient, with a maximum allowable content of secondary amines set at 0.5% to reduce the precursor material for nitrosamine creation.