[The toxicological, hygienic and clinical aspects of the action of low levels of organic solvents].

The article presents experimental data showing that Average Shift Concentration (ASC) and Maximal Single Concentration (MSC) for some solvents (tetrachloromethane, tetrachloroethane, dimethylformamide, benzene) are expedient to be justified. Clinical and hygienic materials proved significant health parameters (nervous system, peripheral blood) and urine levels of main metabolites to depend on chlorbenzene and toluene concentrations influencing the workers. Having analyzed the results, the authors recommended following hygienic norms in the air of workplace: for chlorbenzene ASC--50 mg/cu m, MSC--100 mg/cu m; biologic MAC for urine 4-chlorcatechol--0.

[Materials for the substantiation of the biological MAC of benzene].

Relatively great amount of benzene-originated phenol, the presence of a definite relationship between phenol amount in the urine and benzene content in the air indicate that it is reasonable to use a phenol sample as an exposure test. To determine the intensity of benzene exposure, data on phenol content in the urine of people working at some big-tonnage enterprises has been analyzed. On the basis of the national and foreign literature data on the correlation between the phenol urine concentration and the level of benzene exposure a regression equation was deduced, which has made it possible to calculate phenol content in the urine on the level of average working day benzene concentration adopted in the USSR.