Among all of these reported episodes, no workers changed jobs or were forced to stop work. All skin test investigations were negative, and the CCP came from different manufacturers. Calnan hypothesized that if there was a responsible agent, it was most likely to be the solvent in the microcapsules, which could include kerosene, diarylethanes, alkyl naphthalenes, cyclohexane, and dibutyl phthalate.
Cronin 1980. Cronin [1980] reported that four workers involved in the making of microcapsules for CCP in the United Kingdom were found with eczema of the hand (which had been present in one worker for 4 years) or palms (present in one worker for 10 years). Two Proxel compounds (Imperial Chemical Industries) were used as preservatives for gelatin in a factory making the emulsion for CCP. Both contained the active ingredient 1,2-benzisothiazolin-3-one, and one also contained ethylenediamine. Both the active ingredient and the Proxel provoked positive skin-patch test reactions in all four workers, but the ethylenediamine provoked a response in only two of them [Kanerva et al. 1993]. The author concluded that two of the workers' eczema predated their contact with the agents, and the sensitization was thought to be an aggravating factor in their dermatitis rather than its complete cause. Another dermatitis case was cited in a paper mill worker.
Dodds and Butler 1981. In Belgium in 1975, these investigators described five female workers who handled paper forms and reported skin and eye irritation (specifically eczema, itching, and red spots). An additional 12 workers reported itching of the eyes. The incident coincided with the use of a new desensitizing ink ("D-ink," a coating to disable the color formation process). Before the use of this ink, no symptoms had been reported for 7 years. A hamster cheek-pouch test resulted in transient ischemia that lasted approximately 15 min. Detailed studies of the new desensitizing formula led to the conclusion that one of its ingredients (1-hydroxyethyl-2-oleylimido-azoline) caused the severe effect. In a second case in Denmark, similar symptoms were reported after workers handled paper that contained the same desensitizing ink. The manufacturer was reported to have immediately terminated production of the formulation.
Marks 1981. Marks [1981] reported the following case of a 21-year-old woman in the United States who had a 1.5-year history of an intermittent eruption of the face and neck. She worked as a clerk in a college registrar’s office where CCP forms were used for student registration. Within 24 to 48 hr after using the forms, she developed pruritic, erythematous, and edematous dermatitis. She was skin-patch tested with a standard series of allergens as well as with pieces of paper and the components of the paper backing. She reacted to three of the four colored sheets of CCP. She also tested positive to the color former, identified as paratoluene sulfinate of Michler's hydrol, a component of some CCP. She was further skin-patch tested with paratoluene sulfonic acid (results were negative) and with the Michler's hydrol (4,4N-bis[dimethylamino]benzhydrol) (results were positive). Twelve control subjects tested negative to the paper and coating materials.
Menné et al. 1981. Menné et al. [1981] performed an investigation resulting from 70 complaints at a telephone company in Denmark that employed 2,600 workers who handled up to 900,000 sets of CCP per year (i.e., an average of 1.3 sets per person per day). They first investigated 38 of the complaints and found that 26 workers had skin symptoms only, 9 had skin and mucous membrane symptoms, and 3 had mucous membrane symptoms only. Among the workers with skin symptoms, 22 reported that they started on the hands, and 4 reported that they began on the face. The skin
