BTEX, or benzene, toluene, ethylbenzene and xylenes, are water-insoluble volatile organic compounds, that are clear, colorless, highly flammable liquids, have a sweet smell and evaporate rapidly at room temperature.

BTEX are found naturally in crude oil, petroleum and petroleum products, such as gasoline, coal and wood tar. BTEX are also released through emissions from motor vehicles and aircrafts, and cigarette smoke. BTEX and are used in the production of a variety of consumer goods, including industrial chemicals, rubber, leather, plastics, cleaners and paints, and paint thinners.

GAC, granular activated carbon, filters (GAC) are proven to be very efficient in the removal of benzene, toluene, ethyl benzene and p-Xylene (BTEX) from aqueous solution.