Toluene remained the most common solvent and was used in combination with xylenes, ethyl acetate, and methanol. There was an increase in the use of dichloromethane as a degreasing agent.

Exposure monitoring by personal diffusive samplers, biological monitoring of toluene exposure by urinary hippuric acid determination, haematology, serum biochemistry for liver function, and a subjective symptom survey by questionnaire were conducted on 303 male solvent workers. They were exposed to a mixture of solvents including toluene (geometric mean 18 ppm), methyl ethyl ketone (MEK; 16 ppm), isopropyl alcohol (IPA; 7 ppm), and ethyl acetate (9 ppm). The intensity was mostly below unity using the additiveness formula based on current Japanese occupational exposure limits, but more than eight times unity at the maximum. The results were compared with the findings in 135 non-exposed male workers of similar ages. Haematology and liver function tests did not show any exposure related abnormality, and subjective symptoms were mostly related to central nervous system depression and local irritation. Further analysis suggested that the irritation effects were not related to exposure to MEK. Analysis of the relation between toluene exposure and hippuric acid excretion in urine showed that there was no metabolic interaction between MEK and toluene, or between IPA and toluene. Overall, therefore, it is concluded that there was no sign or symptom detected to suggest anything other than toluene toxicity, that there was no evidence to indicate any modification of toluene toxicity or metabolism due to coexposure, and that the additiveness assumption is reasonable for risk assessment for the combination of solvents under these exposure conditions.(Occup Environ Med 1994;51:523-529) Organic solvents are common materials in modem industries. They are generally used as mixtures, typically in thinner, adhesive, ink, and paint preparation.'' This contrasts with the fact that the toxicity profiles are usually described in textbooks as those of single, pure chemicals, and that toxicity of solvent mixtures is uncertain.It is to be expected that the toxicity of solvent mixtures will vary depending on the toxicity of the individual solvent constituents. It is, however, also true that toluene is the solvent present in the largest proportion in many cases,"13 suggesting that the major toxicity profile may be predominantly determined by toluene, with other solvents as minor toxicity modifiers.The present study was initiated to investigate this possibility by examining dominant toxicity pictures among solvent workers exposed primarily to toluene, together with other common solvents such as ethyl acetate, methyl ethyl ketone (MEK), and isopropyl alcohol (IPA). Materials and methods WORKERS STUDIEDThe study was conducted in the second half of working weeks (on Thursdays and Fridays). In total, 303 male solvent exposed workers and 136 male non-exposed controls were studied. The solvent exposed employees worked in printing, ink production, or surface treatment plants (where the surface of materials were treated with plastics disolved in solvents). Control subjects were office workers and were recruited from clerical sections of t...

Both personal diffusive sampling (at up to 100 ppm DCM and for up to 4 h) and biological exposure monitoring by urinalysis for DCM are applicable in occupational health as reliable measures of exposure to this chlorinated hydrocarbon solvent.

Diffusive sampling with carbon cloth as an adsorbent can be applied to ambient air monitoring of exposure to 1-butanol. Urinalysis for 1-butanol after hydrolysis is sensitive enough to detect occupational 1-butanol vapour exposure at 3 ppm.