n-hexane polyneuropathy in Japan: a review of n-hexane poisoning and its preventive measures

Environ Res. 1993 Jul;62(1):76-80. doi: 10.1006/enrs.1993.1091.


n-Hexane is used in industry as a solvent for adhesive, dry cleaning, and vegetable oil extraction. In 1963, the first case of severe polyneuropathy suspected to be caused by n-hexane was referred to us. Case studies, animal experiments, and field surveys on n-hexane poisoning were conducted, and preventive measures like threshold limit value revision and biological monitoring were also studied. I review a brief history of our investigations on n-hexane poisoning and its preventive measures in Japan. n-Hexane could cause overt polyneuropathy in workers exposed to more than 100 ppm time-weighted average concentrations [TWA]. The present threshold limit value of 40 ppm in Japan is considered low enough to prevent subclinical impairment of peripheral nerve caused by n-hexane. Urinary 2,5-hexanedione could be a good indicator for biological monitoring of n-hexane exposure. About 2.2 mg/liter of 2,5-hexanedione measured by our improved method corresponds to exposure of 40 ppm (TWA) of n-hexane.

Publication types

  • Review

MeSH terms

  • Animals
  • Hexanes / poisoning*
  • Hexanones / urine
  • Humans
  • Japan / epidemiology
  • Nervous System Diseases / epidemiology
  • Nervous System Diseases / etiology*
  • Occupational Exposure
  • Poisoning / complications
  • Poisoning / physiopathology


  • Hexanes
  • Hexanones
  • n-hexane
  • 2,5-hexanedione