>What is hexane

HEXANE - A colorless volatile liquid derived from distillation of petroleum
and used as a solvent for spice oleoresins.  Also used in low-temperature
thermometers instead of mercury, usually with a blue or red dye.  It is a
mild central nervous system depressant that may be irritating to the
respiratory tract.  The FDA data bank, PAFA, has fully up to date toxicology
information available for this aditive.

From A Consumer's Dictionary of Food Additives by Ruth Winter, M.S. (fouth
edition)