Triethanolamine

Triethanolamine
IUPAC name	2,2',2"-Nitrilotriethanol
Other names	Tris(2-hydroxyethyl)amine, 2,2',2"-Trihydroxy-triethylamine, Triethylolamine, Trolamine, TEA, TEOA
Identifiers
CAS number	102-71-6 Y
PubChem	7618
EC number	203-049-8
KEGG	C06771
ChEBI	28621
RTECS number	KL9275000
SMILES	OCC[N](CCO)CCO
InChI	1/C6H15NO3/c8-4-1-7(2-5-9)3-6-10/h8-10H,1-6H2
Properties
Molecular formula	C6H15NO3
Molar mass	149.188 g/mol
Appearance	Pale yellow liquid, hygroscopic
Density	1.126 g/cm3
Melting point	20.5 °C, 294 K, 69 °F
Boiling point	335.4 °C, 609 K, 636 °F (208 °C at 20 hPa)
Solubility in water	Miscible
Hazards
MSDS	ScienceLab.com
R-phrases	R36 R37 R38
S-phrases	S26 S36
NFPA 704	1 2 0
Flash point	179 °C
Autoignition temperature	325 °C
Explosive limits	3.6 - 7.2 %
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Triethanolamine, often abbreviated as TEA, is an organic chemical compound which is both a tertiary amine and a tri-alcohol. A tri-alcohol is a molecule with three hydroxyl groups. Like other amines, triethanolamine acts as a weak base due to the lone pair of electrons on the nitrogen atom. Triethanolamine can also be abbreviated as TEOA, which can help to distinguish it from triethylamine.

Production

Triethanolamine is produced by reacting ethylene oxide with aqueous ammonia; the reaction also produces amonoethanolamine and a diethanolamine. The ratio of the products can be controlled by changing the stoichiometry of the reactants.^[1]

Applications

This chemical is used primarily as an emulsifier (and infrequently as a pH balancer) in many different cosmetic products - ranging from cleansing creams and milks, skin lotions, eye gels, moisturizers, shampoos, shaving foams etc. TEA is a fairly strong alkali: a 1% solution has a pH of approximately 10. Hence it is nowhere near the pH of skin, which is slightly acid (below pH 7). Cleansing milk/cream emulsions based on TEA are particularly good at removing makeup. Because of its high alkalinity and the slight possibility of nitrosamine formation, it was expected by cosmetic chemists such as S.J. Strianse, that TEA would have disappeared from mainstream cosmetics by the 1980s. However, the chemical has proved tenacious, and is still widely used as of 2009. This may be due to the conservatism of the cosmetic industry, or to cost factors, or to other factors.

TEA has also been used in photographic (silver halide) processing. It has been promoted as a useful alkali by photographers who make their own chemical mixes.

Another common use of TEA is as a complexing agent for aluminium ions in aqueous solutions. This reaction is often used to mask such ions before performing what is called a complexometric titration with another chelating agent such as EDTA, which will form stable complexes with most metallic ions.

Triethanolamine is also used as organic additive (0.1 wt. %) in the grinding of cement clinker. It is proved to be very effective to facilitate the grinding process by preventing agglomeration and coating of the powder at the surface of balls and mill wall. ^[2] To what extent could TEA complex heavy metals and radionuclides encapsulated in cement matrix and so could increase their solubility remains an open question.

Various ear diseases and infections are treated with eardrops containing triethanolamine polypeptide oleate-condensate, such as Cerumenex in the United States.

TEA is listed under Schedule 3, part B of the Chemical Weapons Convention as it can be used in the manufacture of nitrogen mustards.

Safety

"As with any amines, it may have the potential to create nitrosamines, but with the low concentrations used in cosmetic products the chances of that happening is very slim and it is further theorized that nitrosamines cannot penetrate the skin."^[3]

References

See also

• Complexometric titration
• Diethanolamine
• Ethanolamine
• Ethanol
• Triethylamine