Field survey on types of organic solvents used in enterprises of various sizes

Abstract

To examine (1) common types of organic solvent work and prevalent types of solvent used, and (2) possible association of high solvent concentration with types of solvent work and with enterprise size. The present survey was conducted in Kyoto, Japan, in April 2004 to March 2005. Air samples were collected in 1,010 solvent workplaces (SWPs) (>or=5 samples/SWP) in 156 enterprises of various sizes, and analyzed for 47 legally designated organic solvents by flame-ionization detector-equipped gas-liquid chromatography. The geometric mean value of the concentrations (after summation by use of the additiveness formula) in the >or=5 samples were taken as a representative value for the SWP. Solvent works were classified into 11 categories according to the Japanese regulation. Enterprises were classified in terms of number of employees. Degreasing (including cleaning and wiping) was the most common type of solvent work, followed by painting and printing, and toluene was the most often detected solvent (i.e., in 42% of the 1,010 SWPs). Further observation by types of solvent work disclosed that toluene was most common in printing (61%), painting (78%), and adhesive spreading/adhesion SWPs (47%), whereas isopropyl alcohol was the leading solvent in cases of surface coating (51%) and degreasing/cleaning/wiping SWPs (42%). Use of methyl alcohol was also high (36% of all cases). In contrast, use of hexane in adhesives was limited (12%). There was a reverse size-dependency in solvent concentrations in air of SWPs, being five times higher in enterprises with <or=50 employees as compared with the level in enterprises with >or=501 employees. Among SWPs, concentrations tended to be high in printing workplaces especially in small enterprises. In contrast, the levels were much lower in testing and research laboratories irrespective of enterprise size. Comparison with the results in a previous survey in 1996 (Ukai et al. 1997) showed that use of toluene and xylenes was reduced and use of isopropyl alcohol and methyl alcohol was increased. The need of continuous updating of the target analyte list was stressed in relation to the limitation of the present study. Solvent levels were about five times higher in small enterprises as compared with the levels in large enterprises. There was a gradual shift in solvent use from aromatics to other solvents, typically alcohols. The use of hexane in adhesives was reduced. Solvent levels were relatively high in solvent-drying and printing workplaces and low in degreasing/cleaning/wiping workplaces and testing/research laboratories.