Handbook of Solvents - George Wypych - ChemTech - Ventech!

1262 Pentti Kalliokoski, Kai Savolainen
18.4.9 GLUING
Shoe manufacturing is an industry where toxic solvents have been used. Benzene containing
glues were used until mid-1960’s, at least in Italy. 67 A significant part of the information
on the toxic and carcinogenic effects of benzene on the hematopoietic system originates
from this industry. 68 After benzene, n-hexane became the most important solvent. 67 Epidemiological
evidence on neuropathy caused by exposure to n-hexane comes again largely
from shoe manufacturing. 5 The TLV and the Finnish OEL of hexane is 50 ppm. The concentration
of the toxic metabolite, 2,5-hexanedione is used for biological monitoring of exposure
to n-hexane. The BEI given by the FIOH is 12 μmol/l. The ACGIH BEI is 5 mg/g
creatinine. Shoe glues may also contain toluene, methyl ethyl ketone, and acetone. 69
The mean airborne concentration of n-hexane was 38 ppm (range 4-90 ppm) in the
Finnish shoe industry in the 1980’s. 26 The mean concentrations of acetone and toluene were
131 ppm and 14 ppm. 26 The mean exposure levels in two US shoe manufacturing plants in
the late 1970’s were: toluene 22-50 ppm, methyl ethyl ketone 133-153 ppm, acetone 46-223
ppm, and n-hexane 22-55 ppm. 69 The exposure is, however, easy to control by doing the gluing
in enclosure hoods.
Contact glues contain usually white spirit with low boiling point range (60-90 o C). Its
Finnish OEL is 350 mg/m 3 . The solvent contains n-hexane, earlier usually 5% or more. In
the 1990’s, white spirits containing only ca. 2% n-hexane have become available. Contact
glues are used to fasten seals and strips e.g., in construction and transportation vehicle industries.
Levels have usually been below the OEL in Finland. If contact glues are used for
floor coverings, very high exposures may occur. These glues have, however, largely been
replaced by ethanol- and water-based glues. 24
18.4.10 OTHER
In the production of viscose, the workers are exposed to carbon disulfide. In addition to inhalation
exposure, absorption through the skin may be important. 70 It is strongly
neurotoxic. 71 Its TLV is 10 ppm and the Finnish OEL 5 ppm. Both carry the skin notation.
Urinary 2-thiothiazolidine-4-carboxylic acid concentration can be used for biological monitoring
of exposure to carbon disulfide. Its ACGIH BEI is 5 mg/g creatinine (4 mmol/mol
creatinine) and the BEI given by the FIOH 2.0 mmol/mol creatinine.
Airborne concentrations from less than 0.2 to 65.7 ppm were detected in measurements
conducted in a German plant in the 1990’s. The urinary 2-thiothiazolidine-
4-carboxylic acid levels ranged from less than 0.16 to 11.6 mg/g creatinine. 70 A long time
average of about 8 ppm has been reported in a Dutch factory. 72
In acetate fiber plants, the workers are exposed to acetone. The mean concentration in
the air of three Japanese factories was 372 ppm. Some workers’ exposure levels exceeded
1000 ppm. 73
Exposure to various solvents takes place in pharmaceutical industry. The airborne 8-h
TWA concentrations of methylene chloride were 16-167 ppm in a Finnish factory in the
1980’s. 46
Even though the active ingredients cause the main health risk while pesticides are
used, but the exposure to solvents may also be important. As many as 71 different solvents
were used in the 8000 pesticide formulations sold in Italy in the 1990’s. Among the solvents,
carcinogens such as benzene, carbon tetrachloride, and chloroform were found. 74
Cyclohexanone is used as a coating solvent in audio and video tape production. Airborne
TWA concentrations from 2 to 20 ppm were detected in factory in Singapore. 75 Uri-