After many years of limitation to experimental studies of contact allergic sensitization, 1-chloro-2,4-dinitrobenzene (2,4-dinitro-1-chlorobenzene) has again appeared in the occupational environment as an algicide for cooling water. Four cases of contact dermatitis in air-conditioning repairmen occurred, and a description of the case histories of three of them is given. The authors emphasize the necessity for engineering completely closed systems which afford no human contact with this highly allergenic substance.
Adams RM, Zimmerman MC, Bartlett JB, Preston JF. 1-Chloro-2,4-Dinitrobenzene as an AlgicideReport of Four Cases of Contact Dermatitis. Arch Dermatol. 1971;103(2):191-193. doi:10.1001/archderm.1971.04000140077013