Fourteen of twenty-six migrant workers developed contact dermatitis at a single tomato-strawberry farm in Tennessee. Investigation identified one of eleven pesticides used by the farmer, 2,4-dichloro-6-(o-chloroanilino)-s-triazine anilazine; Dyrene), as the cause of the dermatitis in six of seven workers who were available for patch testing. As a result of this investigation, the label on Dyrene has been revised to warn users of possible sensitization.