Diethanolamine (DEA) is an organic compound containing two hydroxyl (-OH) groups and one secondary amine (-NH-) group.
It belongs to the class of secondary amines and di-alcohols (dialkanolamines), exhibiting both amine and alcohol reactivity.
Due to this dual functionality, DEA acts as a weak base, emulsifier, pH stabilizer, and metal ion complexing agent in numerous industrial formulations.

Molecular Structure:
HO–CH₂–CH₂–NH–CH₂–CH₂–OH

Chemical and Physical Properties

Property	Specification
Appearance	Colorless to pale-yellow viscous liquid
Odor	Mild ammonia-like odor
Molecular Weight	105.14 g/mol
Boiling Point	~269 °C (at atmospheric pressure)
Density (20–25 °C)	1.097 g/cm³
Solubility	Completely miscible with water, ethanol, and glycerol; insoluble in hydrocarbons
pH (1% aqueous solution)	10.0–11.5
Chemical Nature	Weak base, hygroscopic, non-volatile

Applications of Diethanolamine (DEA)

1. Detergent, Cosmetic, and Personal Care Industries

Active base for the formulation of shampoos, liquid soaps, creams, and lotions
pH regulator and stable emulsifier in surfactant systems

2. Oil and Gas Industry

Used for acid gas removal (CO₂ and H₂S) in gas sweetening units
Acts as a corrosion inhibitor in pipeline and refinery systems

3. Agriculture and Fertilizer

Serves as a chelating agent in liquid fertilizers
Functions as a pH stabilizer in pesticide and fungicide formulations

4. Paints, Inks, and Resins

Co-emulsifier in water-based coatings
Improves viscosity, stability, and durability of paints and inks

5. Cement and Construction

Used as a Grinding Aid in cement production
Enhances workability and compressive strength of concrete under varying temperatures

Advantages

Multi-functional and cost-effective across various industries
Excellent chemical stability in alkaline media
High solubility in aqueous systems
Compatible with surfactants, oils, and alcohols

Limitations

Irritant to skin and eyes upon direct contact
Potential formation of carcinogenic nitrosamines in the presence of nitrites
Sensitization risk in long-term exposure, especially in leave-on cosmetic products
Requires dose control in food and pharmaceutical-related applications

Safety and Regulatory Information (GHS / SDS)

H302: Harmful if swallowed
H315: Causes skin irritation
H319: Causes serious eye irritation
H351: Suspected of causing cancer (IARC Group 2B – limited evidence in humans)

Storage and Handling

Store in tightly sealed containers made of polyethylene or stainless steel
Keep in a cool, dry, and well-ventilated area (10–30 °C)
Protect from direct sunlight, heat sources, and oxidizing agents
Use chemical-resistant gloves, safety goggles, and adequate ventilation during handling

Summary

Diethanolamine (DEA) is a versatile alkanolamine used extensively in detergents, gas treatment, agricultural chemicals, and resin production.
Its dual functionality as both an amine and an alcohol makes it a valuable intermediate, though it requires strict handling and dosage control due to toxicity and sensitization potential.