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What Is It?
TEA-Stearate is the triethanolamine (TEA) salt of stearic acid. It is a cream-colored, wax-like solid. In cosmetics and personal care products, TEA-Stearate is used in a variety of baby, bath, eye makeup, fragrance, hair, makeup, nail, personal cleanliness, shaving, skin and suntan preparations.
Why is it used in cosmetics and personal care products?
TEA-Stearate helps to form emulsions by reducing the surface tension of the substances to be emulsified. When used in the formulation of cleansing products, TEA-Stearate cleans skin and hair by helping water to mix with oil and dirt so that they can be rinsed away.
CAS NO:4568-28-9
EC NO:224-945-5
SYNONYMS:Octadecanoic acid, compd. with 2,2',2''-nitrilotris[ethanol] (1:1)
Octadecanoic acid, compd. with 2,2',2''-nitrilotris(ethanol) (1:1)
TEA-Stearate
octadecanoic acid - 2,2',2''-nitrilotriethanol (1:1)
CCRIS 6278
TEA Stearate
Stearic acid, triethanolamine soap
Triethanolamine, stearic acid salt
EINECS 224-945-5
Octadecanoic acid, triethanolamine salt
DSSTox_CID_6219
DSSTox_RID_78063
DSSTox_GSID_26219
DTXSID9026219
Stearic acid, compd. with 2,2',2''-nitrilotriethanol (1:1)
Stearic acid, compound with 2,2',2''-nitrilotriethanol (1:1)
Tox21_200858
NCGC00248977-01
NCGC00258412-01
octadecanoate;tris(2-hydroxyethyl)azanium
CAS-4568-28-9
Abstract
Stearic acid and triethanolamine (TEA) in a molar ratio of 2:1 were mixed in aqueous solution at 80 degrees C and subsequently cooled to ambient temperature. The structural evolution of the resultant sample during storage was characterized by using light microscopy, Cryo-SEM, differential scanning calorimetery, pH, infrared spectroscopy, elemental analysis, and simultaneous small and wide-angle X-ray diffraction. It was found that a lamellar liquid crystalline phase was formed when stearic acid and TEA solution were mixed at 80 degrees C and multilamellar spheres of a few microns diameter were formed initially after cooling. A hydrolysis reaction (i.e., the reverse reaction of neutralization between stearic acid and TEA) occurred thereafter that caused the breakdown of the lamellar gel phase and the formation of platelet stearic acid crystals. Three polymorphs of stearic acid (defined following previous work as the A, C, and E forms) were formed as the result of hydrolysis reaction, which gave rise to a strong optically pearlescent appearance.
Production
Triethanolamine is produced from the reaction of ethylene oxide with aqueous ammonia, also produced are ethanolamine and diethanolamine. The ratio of the products can be controlled by changing the stoichiometry of the reactants.
Reaction of ethylene oxide with ammonia.png
Applications
Triethanolamine is used primarily in making surfactants, such as for emulsifier. It is a common ingredient in formulations used for both industrial and consumer products. The triethanolamine neutralizes fatty acids, adjusts and buffers the pH, and solubilizes oils and other ingredients that are not completely soluble in water. Triethanolammonium salts in some cases are more soluble than salts of alkali metals that might be used otherwise, and results in less alkaline products than would from using alkali metal hydroxides to form the salt. Some common products in which triethanolamine is found are sunscreen lotions, liquid laundry detergents, dishwashing liquids, general cleaners, hand sanitizers, polishes, metalworking fluids, paints, shaving cream and printing inks.
Cement production
Triethanolamine is also used as organic additive (0.1 wt%) in the grinding of cement clinker. It facilitates the grinding process by preventing agglomeration and coating of the powder at the surface of balls and mill wall.
Cosmetics and medicine
Various ear diseases and infections are treated with eardrops containing triethanolamine polypeptide oleate-condensate, such as Cerumenex in the United States. In pharmaceutics, triethanolamine is the active ingredient of some eardrops used to treat impacted earwax. It also serves as a pH balancer in many different cosmetic products, ranging from cleansing creams and milks, skin lotions, eye gels, moisturizers, shampoos, shaving foams,TEOA is a fairly strong base: a 1% solution has a pH of approximately 10, whereas the pH of skin is less than pH 7, approximately 5.5−6.0. Cleansing milk–cream emulsions based on TEOA are particularly good at removing makeup.
The aim of this research was to study the effect of stearic acid and TEA concentration on physical and chemical properties of cosmetic emulsion using coconut oil as raw material. The emulsion was made by emulsification of water phase (glycerin, aquadest and TEA) and oil phase (coconut oil, stearic acid, lanolin, cetyl alcohol). To determine the effect of stearic acid and TEA concentration on properties of emulsion, these components were added in various concentrations. The physical and chemical properties of emulsions were then measured such as pH, viscosity and droplet size. The result showed that the viscosity of emulsions was increased by increasing stearic acid concentration, on the other hand the droplet size decreased. The pH of emulsion was in the range of 7. 58-7. 96. If the TEA concentration was increased, the pH and viscosity were also increased, but it caused a decrease in droplets size. These mean that stearic acid and TEA concentration affected the physical and chemical properties of cosmetic emulsions.
Crystals of partially neutralized stearic acid with triethanolamine (TEA) were prepared by mixing these two materials above 80 degrees C and then cooling. The crystalline composition and the structure and melting behavior of the resultant products were characterized with small-angle and wide-angle X-ray diffraction, thermal analysis, microscopy, and infrared spectroscopy. It was discovered that an acid-soap complex of 2:1 fixed stoichiometric ratio exists between stearic acid and TEA stearate. A binary phase diagram of stearic acid and TEA soap is built based on the experimental results; this is the first published record of a binary phase diagram for amine-based soap. Its behavior is significantly different from that of binary systems of fatty acid and alkali soap.
Safety Information:
The Food and Drug Administration (FDA) allows the individual components of TEA-Stearate to be used in food. Triethanolamine is allowed to be used to wash or aid in the peeling of fruits and vegetables. Stearic acid is on FDA's list of direct food substances affirmed as Generally Recogized As Safe (GRAS). The safety of TEA-Stearate has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that TEA-Stearate was safe in cosmetic formulations. The CIR Expert Panel did not set any limits for the use of TEA-Stearate in products rinsed off shortly after application. Concentrations limits based on the amount of Triethanolamine in the product were set for products intended to be left on the skin.
The behaviour of stearic acid neutralised by triethanolamine to form soap and its acid–soap has been examined by infrared spectroscopy. It was found that not only could the neutralisation behaviour be characterised, but the thermotropic behaviour could also be followed. The neutralisation confirmed the formation of a fixed stoichiometeric ratio, 2 : 1, acid–soap. When following the thermotropic behaviour the break up of the acid–soap could be followed along with various disordering and melting transitions of the alkyl chain tail. This allowed all the thermal transitions that have been observed to be characterised in terms of the type of molecular rearrangement that was occurring and also the transition temperature at which they occurred. This allowed the binary phase diagram to be plotted and understood for this system. This is the first time IR has been used to measure a whole phase diagram of this type. The nature of the acid–soap complex itself was also characterised, with very short hydrogen bonds being present as well as a free, non-hydrogen bonded, hydroxyl group.
Triethanolamine is a synthetic compound that reacts with stearic acid to create an effective emulsifier.
Description
Most often, cosmetics products need to be extremely stable to have a long shelf life in order to be stored, handled, shipped etc. This is why emulsifiers, stabilisers and preservatives are often added in large quantities, which tends to create thick creams loaded with synthetic ingredients. At Lush, we like them to glide on seamlessly and feel lightweight on the skin. This makes the stability more fragile which is why they are best used as fresh as possible; but in exchange, the product can be filled with fresh flowers, fruits and other beneficial plants.
Triethanolamine (TEA) is a common emulsifier used in a vast array of cosmetics, detergents and pharmaceuticals. Cosmetic creams and lotions are often composed of water and oil-based ingredients, which are held together by substances called emulsifiers. Without emulsifiers, the formula would separate, causing oil droplets to float on top of the water.
When triethanolamine is mixed with stearic acid (an acid that is naturally present in butters, oils and waxes - but can also be added separately), it reacts and transforms into a paste called triethanolamine stearate. The paste is emulsifying and helps to create a loose emulsion which is easily absorbed by the skin. If the correct amount of stearic acid is used, triethanolamine will be fully dissolved during the chemical process. This means that it is no longer present in the finished product.
Stearic acid triethanolamine ester was prepared by reaction of stearic acid and triethanolamine. The method of classical column chromatography was employed for the separation of the product stearic acid triethanolamine tri-ester from the reaction product mixture. Structure of the reaction product mixture as well as the first fraction separated from the reaction product mixture was characterized by FTIR and 1HNMR. On the basis of single factor experiments, the reaction conditions were optimized by orthogonal experiments. The effects of reaction temperature, molar ratio of the starting materials and the dosage of catalyst on the content of stearic acid triethanolamine tri-ester in the reaction product mixture were studied. The optimal reaction conditions were identified as: reaction temperature 200 ℃; mole ratio of stearic acid to triethanolamine 3.3︰1.0; and dosage of catalyst 0.1%. Under the optimal conditions, the content of stearic acid triethanolamine tri-ester in the reaction product mixture achieves 97.06%.
TEA Stearate is the triethanolamine salt of stearic acid used as a surfactant-cleansing agent and a surfactant-emulsifying agent in a wide variety of cosmetic formulations. Published data on TEA Stearate as an individual ingredient were not available, but data on its two components, TEA and stearic acid, were previously reviewed and considered adequate to evaluate the safety of TEA Stearate. Information from the earlier reports was summarized in this report and updated with more recent data on TEA. These data were consistent with the conclusion that TEA is safe for use in rinse-off cosmetic formulations, that its concentration should not exceed 5% in leave-on formulations, and that in no case should it be used in products containing N-nitrosating agents. Stearic Acid was found safe as used. Because the TEA salt of stearic acid is not expected to exhibit any toxic effects not seen with the separate moities, these conclusions, including the concentration limit for TEA, are considered applicable to TEA Stearate, once adjusted for the appropriate molecular weights. Therefore, it is concluded that TEA Stearate is safe as used in cosmetic formulations designed for discontinuous, brief use followed by thorough rinsing; that it is safe in concentrations not to exceed 15% in formulations intended for prolonged contact with the skin; and that it should not be used in products under conditions resulting in N-nitrosation reactions.
Major Uses
1, Typical applications
Use as cleansing agent.
Use as emulsifying agent, dispersing agent.
Use as lubricant.
2, Personal care products
Cleansing agent, emulsifying agent in personal care products.
Further information:
In accordance with EU regulations (EC) No 1223/2009, directive 2003/83/EC, triethanolamine and its salts are included in Annex III/62.
Can be applied to leave-on products and rinse-off products.
Maximum concentration is 2.5% in leave-on products (as triethanolamine).
In raw materials, maximum secondary amine content is 0.5%.
Maximum nitrosamine content is 50μg/kg.
The container is nitrite-free.
In accordance with Safety and Technical Standards for Cosmetics (2015 Edition) of China, triethanolamine and its salts are the restricted components.
Can be applied to leave-on products and rinse-off products.
Maximum concentration is 2.5% in leave-on products (as triethanolamine).
In raw materials, maximum secondary amine content is 0.5%.
Maximum nitrosamine content is 50μg/kg.
The container is nitrite-free.
TEA-Stearate is the triethanolamine salt of Stearic Acid. Stearic acid is a fatty acid obtained from animal and vegetable fats and oils and is used primarily as a soap.
Soaps are the salts of water-insoluble fatty acids with various bases. Soaps were the first surface-active agents prepared by man.
Stearic Acid / Triethanolamine / Stearic Acid Triethanolamine - Uses and Benefits
Stearic Acid / Triethanolamine / Stearic Acid Triethanolamine is used for the treatment, control, prevention & improvement of the following diseases, conditions and symptoms:
Viral infection
Inflammation
Wounds
Neutralize fatty acids
When the stearic acid was missing, the mixture was separated. This is because thetriethanolamine and stearic acid need to both be present in order for them to act as an emulsifier. This is similar to mixture number two because in each, one of those two ingredients was missing, causing the mixture to separate. When the lanolin was missing, the mixture was more like a liquid and had soapy looking suds and bubbles. This is because the lanolin is waxy and makes the mixture more creamy and greasy. Without it, the mixture is a liquid instead of a cream.
