Six patients developed chloracne from exposure to 2,6-dichlorobenzonitrile. The patients were involved in the manufacture of a herbicide containing this ingredient. They failed to respond to conventional acne treatment as long as contact with the herbicide persisted.
Deeken JH. Chloracne Induced by 2,6-Dichlorobenzonitrile. Arch Dermatol. 1974;109(2):245-246. doi:10.1001/archderm.1974.01630020057015