Sodium dodecyl sulfate (SDS), also known as K12, is an anionic surfactant with the chemical formula C12H25SO4Na and a molecular weight of 288.38.^[4-5

]It typically appears as a white or pale yellow powder with a slight odor and a smooth texture. It has a melting point of 185–190°C and a density of 1.11 g/cm3. It is highly soluble in water, forming a transparent solution, and slightly soluble in alcohol.

]It is flammable when exposed to open flames or high temperatures and decomposes upon heating, releasing hydrocarbons and sulfur dioxide gas. It reacts with cationic surfactants, lead salts, and potassium salts to form precipitates.