2,3-epoxypropyl trimethyl
ammonium chloride (
EPTMAC) is used in the production of cationic
starch (CS) for the paper industry. It has been shown to be a sensitizer in guinea pigs, but cases of human sensitization are few. 4 workers were previously sensitized to the substance in a Finnish plant. This report describes 3 process men from another plant examined because of recurring
dermatitis. 18 workers were involved in production, and had free access to all work sites. 3 process men, whose work involved drying the CS, had
dermatitis, although they had only occasional contact with the cationizing chemical. 2 were already verified to be allergic to
EPTMAC and had had variable
dermatitis for 8-12 years. One had had
dermatitis on his face for 1 year. Patch testing with a dilution series (1%, 0.5%, 0.2%, 0.1% pet.) confirmed their
allergy to the cationizing chemical containing
EPTMAC, but tests with CS were negative. In addition, 2 had contact
allergy to Cl+ Me-isothiazolinone from contact with Kathon LX used as a slimicide in the process. In long-standing (years) recurrent
dermatitis, re-examination of patients with verified exposure history and skin test is necessary. In line with our previous study, sampling the process materials, maintenance work and contamination of work sites and gloves caused sensitization. The results also confirm that
EPTMAC is a strong human contact sensitizer. 0.2%-0.5% pure
EPTMAC in pet. seems to be the optimal patch test concentration.