Ethanolamine is a colorless, viscous, hygroscopic liquid with an ammonia-like odor at room temperature, soluble in water and alcohols. Its molecule contains both an amino group (-NH₂) and a hydroxyl group (-OH), giving it reactive chemical properties: the amino group makes it weakly basic and able to react with acids to form salts, while the hydroxyl group can participate in reactions such as esterification. Its most important characteristic is its ability to react reversibly with acidic gases (e.g., CO₂, H₂S) to form salt-like compounds. Its main applications include: serving as a key absorbent for desulfurization and decarbonization in natural gas and refinery gas purification; producing critical surfactants (ethanolamides) used in personal care products such as shampoos and body washes; and acting as an important organic intermediate in the synthesis of pesticides, pharmaceuticals, rubber processing agents, and cement grinding aids, among others.