Hydroxyethyl Cellulose(HEC) Hydroxyethyl cellulose is a gelling and thickening agent derived from cellulose. It is widely used in cosmetics, cleaning solutions, and other household products. Hydroxyethyl cellulose is also used extensively in the oil & gas industry as a drilling mud additive under the name HEC as well in industrial applications, paint & coatings, ceramics, adhesives, emulsion polymerization, inks, construction, welding rods, pencils and joint fillers.