from wiki
Toxicity
The acute
toxicity of hexane is relatively low, although it is a mild
anesthetic. Inhalation of high concentrations produces first a state of mild
euphoria, followed by
somnolence with
headaches and
nausea.
The long-term
toxicity of
n-hexane in humans is well known.
[6] Extensive peripheral nervous system failure is known to occur in humans chronically exposed to levels of
n-hexane ranging from 400 to 600
ppm, with occasional exposures up to 2,500 ppm. The initial symptoms are tingling and cramps in the arms and legs, followed by general muscular weakness. In severe cases,
atrophy of the
skeletal muscles is observed, along with a loss of coordination and problems of vision. Similar symptoms are observed in animal models. They are associated with a degeneration of the
peripheral nervous system (and eventually the
central nervous system), starting with the distal portions of the longer and wider nerve
axons. The toxicity is not due to hexane itself but to one of its
metabolites,
hexane-2,5-dione. It is believed that this reacts with the
amino group of the
side chain of
lysine residues in
proteins, causing
cross-linking and a loss of protein function.
Chronic intoxication from hexane has been observed in
recreational solvent abusers and in workers in the
shoe manufacturing, furniture
restoration and
automobile construction industries, and recently, plastic recyclers and assemblers and cleaners of capacitive touch-screen devices
[7].
In 1994, n-hexane was included in the list of chemicals on the US Toxic Release Inventory (TRI).[8] In 2001, the U.S. Environmental Protection Agency issued regulations on the control of emissions of hexane gas due to its potential carcinogenic properties and environmental concerns.[9]
In the latter part of the 20th and early part of the 21st centuries, a number of explosions have been attributed to the combustion of hexane gas.[
citation needed]
Use in food processing
According to a report by the
Cornucopia Institute, hexane is used to extract oil from grains as well as protein from soy, to such an extent that in 2007, grain processors were responsible for more than two-thirds of hexane emissions in the United States.
[10] The report also pointed out that the hexane can persist in the final food product created; in a sample of processed soy, the oil contained 10 ppm, the meal 21 ppm and the grits 14 ppm hexane.
[10] The adverse health effects seem specific to
n-hexane; they are much reduced or absent for other isomers. Therefore, the food oil extraction industry, which relied heavily on hexane, has been considering switching to other solvents, including
isohexane.
[11][12][13]
Poisoning from touchscreen cleaner
In February 2010, reports surfaced saying that an employee of
Wintek Corporation (a company that supplies touchscreen components to technology companies) died in August 2009 due to n-Hexane poisoning. n-Hexane was used as a replacement to
alcohol for cleaning screens. The report also revealed that another 49 employees required treatment for n-Hexane poisoning around the same time.
[14] This number was later increased to 62.
[15] In October 2010, further reports surfaced of another exposure to n-Hexane at a Wintek manufacturing facility located in
China. An
ABC Foreign Correspondent episode covertly interviewed several women who had been in the hospital for over six months. The women claimed that they were exposed to n-hexane while manufacturing
iPhone hardware.
[16][17]