Triethyl Citrate (TEC) is a clear, practically colorless, and odorless oily liquid widely utilized across multiple consumer and industrial sectors. It is often produced from the fermentation of natural citric acid with ethanol. Chemically, TEC is classified as an ester, an organic compound formed when an acid bonds with an alcohol. Its broad application base stems from its ability to enhance product properties without introducing strong odors or colors.
Chemical Structure and Technical Function
Triethyl citrate is formally the triethyl ester of citric acid, formed by the chemical reaction between three molecules of ethanol and one molecule of citric acid. Its specific chemical structure (C12H20O7) is responsible for its technical capabilities in various formulations.
One primary function is as an effective plasticizer, a substance added to materials to make them softer, more flexible, and less brittle. When added to polymers or resins, TEC reduces the internal friction between molecular chains, making the final product more pliable and easier to process.
TEC also acts as an excellent high-boiling solvent, facilitating the uniform mixing and dispersion of other ingredients. In applications such as coatings, it functions as a film former, helping to create a smooth, continuous layer as the product dries. These properties allow it to stabilize complex mixtures and improve texture and consistency.
Common Uses in Consumer Products
The multi-functional nature of TEC makes it a common ingredient in a variety of consumer products.
Personal Care and Cosmetics
In the cosmetics and personal care industry, TEC is a frequent component in deodorants. Here, it functions as an active odor-reducing agent by inhibiting the enzymatic breakdown of sweat components that generate body odor. Triethyl citrate is also utilized extensively as a plasticizer in nail polishes and lacquers, improving film flexibility and preventing chipping. In other personal care items like moisturizers and serums, its role is to enhance the texture and spreadability of the product, and it can serve as a perfume fixative, stabilizing fragrance compounds.
Food Industry
In the food industry, TEC is recognized under the European food additive number E1505. It is used as a flavor solvent and a stabilizing agent to help maintain the structure of food items. For example, it is specifically used as a whipping aid to stabilize foams, particularly in the production of dried egg whites.
Pharmaceuticals
The pharmaceutical sector relies on TEC’s plasticizing properties for the coating of tablets and capsules. Applying TEC to the polymer film improves the film’s flexibility and integrity. This ensures the coating does not crack during manufacturing or storage, which is relevant for various dosage forms, including oral tablets.
Safety and Regulatory Status
Regulatory bodies have extensively reviewed triethyl citrate, addressing concerns regarding chemical ingredient safety. The United States Food and Drug Administration (FDA) has affirmed TEC as Generally Recognized As Safe (GRAS) for its use as a direct human food ingredient. This status applies when TEC is used as a flavoring agent, solvent, or surface-active agent in foods, with usage limited by current good manufacturing practices.
This high level of safety is attributed to how the body processes the compound. When ingested or absorbed, TEC is rapidly metabolized by enzymes through hydrolysis. This process breaks the molecule down into two naturally occurring substances the body can easily process: citric acid and ethanol.
Triethyl citrate has a low toxicity profile and is readily biodegradable. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that TEC is safe for use in cosmetics. Its acceptance as a food additive in Europe (E1505) and its inclusion in the FDA’s Inactive Ingredients Database for oral medications further solidify its standing.