Dose-response assessments of Kathon biocide (I). Diagnostic use and diagnostic threshold patch testing with sensitized humans.

Nearly all effective, commercially available preservatives possess skin sensitization potential. This manuscript describes a program of diagnostic patch and practical use testing of consumer products that contained Kathon CG, a relatively new biocide. A series of threshold diagnostic patch tests demonstrated that the minimal elicitation concentration in occluded patch testing of allergic subjects considerably exceeded the concentrations of the biocide typically present in normal diluted use of the test products. Use testing further confirmed a threshold exposure for eliciting allergic reactions. It showed that even subjects who have delayed contact hypersensitivity to Kathon CG used rinse-off personal care products preserved with this agent without experiencing elicitation of these allergies.