Sensitivity to m-phenlenediamine.

Primary contact sensitivty to m-phenylenediamine was noted in 8 of 182 workers handling this substance as hardener. In these patients the period between the beginning of this work and the appearance of dermatitis was shorter if they became simultaneously sensitive to epoxy resin and/or triethylenetetramine. Moreover from among 150 consecutive patients one was positive to m-phenylenediamine and negative to p-phenylenediamine. From among the selected patients positive to p-phenylenediamine more than 40 per cent were also positive to m-phenylenediamine. A large number of the latter patients were as well positive to o-phenylenediamine. No patients were found who would be positive to o-phenylenediamine and negative to m-phenylenediamine. Nearly all those positive to m- and p-phenylenediamine were also positive to the meta isomers of other aromatic amines.