Hydroxyethyl cellulose (HEC) is a water-soluble polymer derived from cellulose, the main component of plant cell walls. It is made by treating cellulose with a combination of heat, pressure, and chemicals, such as alkali and ether, which modifies the cellulose molecules to create a new compound with different properties. HEC is a white, free-flowing powder that is highly water-soluble and forms a thick, clear gel when mixed with water.

HEC is used in a wide variety of applications due to its thickening, gelling, and stabilizing properties.

In the food industry, it is used as a thickener, emulsifier, and stabilizer in products such as ice cream, salad dressings, and sauces.

In the pharmaceutical industry, HEC is used as a binder and disintegrant in tablet manufacturing, as a thickener and suspending agent in liquid formulations, and as a lubricant in capsules and tablets.

In the oil and gas industry, HEC is used as a viscosifying agent in drilling fluids to increase the fluid's ability to carry cuttings. It is also used to increase the gel strength of the fluid, which helps to improve hole stability and reduce the risk of lost circulation.

In the cosmetics industry, it is used as a thickener, emulsifier, and stabilizer in lotions, creams, and other personal care products.

HEC is also used in many other industrial applications, such as in paper manufacturing, as a thickener and binder in adhesives, and as a thickener in paints and coatings.