Triethanolamine (TEA) is an organic compound with the chemical formula C₆H₁₅NO₃, classified as a tertiary amine and a tri-hydric alcohol.
It is produced by the reaction of ethylene oxide with ammonia, and contains three hydroxyl (-OH) groups and one tertiary amine (-N<) functional group.

Molecular Structure:
HO–CH₂–CH₂–N(CH₂CH₂OH)₂

This structure enables TEA to act as a weak base, emulsifier, pH stabilizer, and strong solvent in various formulations.

Physical and Chemical Properties

Property	Value / Description
Appearance	Clear, colorless to pale yellow viscous liquid
Odor	Mild, ammoniacal, slightly sweet odor
Molecular Weight	149.19 g/mol
Boiling Point	335 – 335.4°C
Melting Point	~21.2 – 21.6°C
Density (25°C)	1.124 – 1.127 g/cm³
Viscosity (25°C)	~450 cP (relatively high)
Solubility	Completely miscible with water, ethanol, and acetone
pH (1% aqueous solution)	10.5 – 11.5

Applications

1. Cosmetics and Personal Care

pH adjuster in creams and lotions
Emulsifying agent in shampoos and shaving gels
Foam booster in mild cleansing formulations

2. Oil, Gas, and Drilling

Corrosion inhibitor in oil and gas transportation systems
Additive in drilling fluids

3. Textile Industry

Lubricant and softening agent in dyeing and finishing processes
Dye fixative for synthetic fibers

4. Pharmaceuticals

Base for ointments, creams, and topical formulations
Used in slow-release tablet formulations

5. Paints, Inks, and Coatings

Viscosity stabilizer and pH regulator
Improves dispersion and prevents pigment settling

6. Cement and Construction

Grinding aid in cement production
Enhances workability and strength of concrete

Advantages

Excellent buffering capacity for pH control
High solubility in both aqueous and organic systems
Multifunctional — acts as solvent, surfactant, and complexing agent
Suitable for low-odor and non-irritating formulations

Disadvantages

May cause skin sensitization upon repeated contact
Limited thermal stability at elevated temperatures
Requires precise dosage control in cosmetic formulations
Potential to form nitrosamines in the presence of nitrites under certain conditions

Safety and Handling

GHS Classification:

H315: Causes skin irritation
H319: Causes serious eye irritation
H335: May cause respiratory irritation

Safety Precautions (HSE):

Use protective gloves, safety goggles, and ensure adequate ventilation
Avoid direct contact with skin and eyes, and prevent inhalation of vapors
Store in tightly closed containers at ambient temperature, away from direct sunlight

Transportation Information:

UN Number: 2491
Hazard Class: 8 (Corrosive substances)

Summary

Triethanolamine (TEA) is a versatile, multifunctional chemical widely used in formulation, refining, textile, and construction industries.
With its unique ability to control pH, stabilize emulsions, and enhance compatibility with diverse raw materials, TEA remains one of the most valuable additives in modern industrial chemistry.