Handbook of Solvents - George Wypych - ChemTech - Ventech!

20.7 Hepatotoxicity 1389
vents. It is highly likely that, in predisposed individuals, toluene can cause liver damage
from chemical hepatitis to necrosis and fibrosis.
20.7.8 DICHLOROMETHANE
Dichloromethane also called dichloromethane, is a colorless liquid that has a mild sweet
odor. It is used widely in the industry as a solvent and a paint stripper. It is commonly found
in spray painting operations, automotive degreasing, in cleaners and in household products.
Stewart et al. 63 showed no changes in liver enzymes in patients exposed for a period of 6
weeks to levels of dichloromethane via inhalation from 50-500 ppm. On the other hand, Ott
et al. 64 has shown an elevation in bilirubin in workers exposed to dichloromethane up to 475
ppm. In experimental animals dichloromethane exposure has been associated with fatty
changes of the liver and elevated liver enzymes. Norpoth et al. 65 have shown hepatic
microsomal enzyme elevation at 500 ppm of dichloromethane exposure for 10 days, and
others have shown significant fatty changes of the liver upon exposure of mice and rats for
100 days to 75-100 ppm of trichloroethylene. 66,67,68 When exposure to dichloromethane continues
for 2 years there was increased evidence of pathological changes and fatty liver
changes. 69,70,71 The overall weight of the data supports a hepatotoxic effect of dichloromethane
on the liver.
20.7.9 STODDARD SOLVENT
Stoddard solvent is a widely used organic solvent synthetically made, and comes from the
refining of crude oil. It is a petroleum mixture made from distilled alkanes, cycloalkanes
(naphthenes), and aromatic compounds. In addition, it goes by other names such as Varsol
1, Texsolve S and others. It is commonly used as a paint thinner, as solvents in some types of
photocopier toners, printing ink, adhesives, dry cleaning and as a general cleaner and degreaser.
Twelve men exposed to 610 mg per cubic meter of vaporized Stoddard solvents for
a period of 6 hours revealed no changes in serum glucose, triglycerides, cholesterol or
urate. 72 Dossing et al. 73 described painters who were exposed to non-specified levels of
Stoddard solvents and other chemicals for chronic periods, and elevated levels of serum
alanine aminotransferase, but other functions were normal and normal liver biopsies. Flodin
et al. 74 has studied a group of patients exposed to a variety of solvents, including Stoddard
solvents and showed normal liver function tests, but an elevated gamma glutamyl
transferase. Hane et al. 75 has shown that a group of painters exposed to Stoddard solvents
had no significant abnormality of liver enzymes. Studies in experimental animals showed
minimal fatty changes of the liver, Jenkins et al. 76 as did the studies by Carpenter and Phillips.
77,78,79 The data from experimental animals and humans suggests a potential hepatotoxic
effect of Stoddard solvents, but additional studies and a case by case evaluation is required.
20.7.10 1,1,1-TRICHLOROETHANE
1,1,1,-Trichloroethane is a colorless solvent which is manmade. It is produced by industry
and is used in commercial products. It is used as a solvent, and is heavily used in glue and
paint, as well as a degreaser and metal parts manufacturing. It is also used in some household
products such as spot cleaners, glues and aerosol sprays. It is commonly found in soil
and water as a contaminant. Brief single exposures to very high levels of
1,1,1-trichloroethane and a moderate high concentration have been shown to cause elevation
of urobilinogen in patients. 80 This type of finding indicates reduced bile excretion and
some intrinsic liver damage. Stewart et al. 81 showed in patients accidentally exposed to a
high concentration of 1,1,1-trichloroethane increased levels of urinary urobilinogen for ap-