The chemical tetrahydrofuran is an organic, highly flammable, colorless liquid that mixes well with water and has a molecular formula of C4H8O. Tetrahydrofuran is a stable chemical with strong reducing and oxidizing agents. Exposure through the eyes, skin or respiratory passages can upset the central nervous system and otherwise cause irritation. Also known as butylene oxide, cyclotetramethylene oxide, diethylene oxide, hydrofuran, tetra-methylene oxide, furanidine, or Oxolane, tetrahydrofuran works well as a solvent and smells much like diethyl ether. Once polymerized, it is also used in synthetic fiber production. Hundreds of thousands of tons of this chemical are manufactured each year, much of which ends up in PVC glues, varnishes, and other solvents. Additional uses include industrial metal parts degreaser and, due to its higher boiling point, as an occasional laboratory solvent. In biochemistry, tetrahydrofuran has endless uses, including delipidation of brain lipid proteins and dehydrating plant tissue to embed paraffins.