Relationship between exposure and environmental concentrations in organic solvent workplaces.

The correlation between the exposure concentration (ExpC) of workers and the environmental concentration (EnvC) in their workplaces were examined in 143 printing, painting, gluing, degreasing and other solvent workplaces manned by 535 workers of both sexes. ExpC was measured with carbon felt dosimeters, and EnvC was with grab sampling of air into poly-tetrafluoroethylene bags; both were followed by GC analyses. When ExpC and EnvC were compared on both group and individual basis, the correlation was found to be positive but rather weak, and individual difference in ExpC within the workers of the same workplace was not negligible. Workplaces were classified after regulatory practice into three categories, and attempts were made to find out the conditions so that none among the 174 workers in the 43 Category 1 (i.e., "clean" from regulatory view point) workplaces would be exposed to solvent vapors over the current occupational exposure limit (OEL). Accordingly, it was found that the requirement will be met in case half the OEL is taken as the E value (the EnvC limit set by the regulation). Thus, the same conclusion was reached through the analyses of two separate batches of experiences, i.e., one in the present study and the other in the previous report (Ikeda and Ohtsuki 1985).