ventilation. The solvent concentrations were relatively higher in printing shops than in offices, but the number of health problems in the printing shops was low. The authors cited a study by Hasegawa et al. [1973] that found a diisopropylnaphthalene concentration of 0.3 mg/m3 in the air at a sorting department in which each worker daily handled 50,000 to 70,000 CCP sheets containing the solvent. They also cited an unpublished report by Dodds [1980] who found hydrated terphenyl concentrations in the ppb range during the production of microcapsules containing color former dissolved in hydrogenated terphenyls. Norbäck and Göthe [1983] conclude that the measured dust concentrations did not contain solvents in sufficient quantity to be associated with primary irritation. This study is unclear as to whether encapsulated CCP solvent attached to airborne fibers is extractable by carbon disulfide and is thus included in measurements of dust-bound solvent. This study did not consider the effect of high local concentrations of solvent on the epidermis when a microcapsule fractures. Also unresolved are the relative skin exposures for workers in offices and printing plants. Although printing plant workers process a far greater tonnage of paper than office workers, its not clear whether printing plant workers have more or even as much skin contact as CCP users in offices.
Olsen and Mørck 1985. Olsen and Mørck [1985] extensively studied a brand of CCP that was dominant in the Scandinavian countries at that time. They performed gas chromatography/mass spectrometry (GC/MS) analysis, finger analysis of the residual CCP components on the skin, analysis of keyboard surfaces of computers and typewriters, microbiological analysis of the microcapsules, analysis of the mucous membranes of the nose, electron microscope studies of the skin using tape before and after handling CCP, dust measurements, and headspace analysis of CCP emissions. The authors found that hydrogenated terphenyls are transferred to the skin (120 μg per sorting finger) along with their impurities of bi-, tetra-, and pentaphenyls, but they did not find kerosene in detectable amounts owing to its volatile nature. The ratio of hydrogenated terphenyls to kerosene in the microcapsules was 1:3; but after rupture, analysis of the CF layer revealed that more than half of the kerosene had evaporated. Analysis of exposed workers' mucous membrane secretions failed to reveal any CCP components. Headspace analysis demonstrated that kerosene evaporated from the CCP without mechanical rupture of the microcapsules (value not given). The amount evaporating increased after rupture (the highest concentration found in room air was 1.9 mg/m3 [0.3 ppm]), but hydrogenated terphenyls were not released into the air as vapor. Analysis of keyboards revealed concentrations of hydrogenated terphenyls and transfer of this compound to telephones, table tops, etc. in the office. Measurements of total dust ranged from 0.11 to 0.21 mg/m3, and no chemical components of the CCP were associated with it. No growth of fungi or bacteria resulted from the incubation of microcapsules, but one base paper sample (not CCP) supported the growth of actinomycetes at 50 °C. Electron microscopy did not show transfer of the clay/kaolin components to the hands after 3 hr of handling CCP.
Apol and Thoburn 1986, Chovil et al. 1986, and Burton and Malkin 1993. See Section 4.2.1 for a discussion of these studies.
Omland et al. 1993. See Section 4.2.3.2 for a discussion of this study.
Zimmer and Hadwen 1993. In response to a request from the management of the Federal Records Center in Dayton, Ohio, Zimmer and Hadwen [1993] investigated six worker complaints of an overpowering, irritating odor in the archives area where Federal tax records and X-ray films were stored. Acetic acid was the
