Contact hypersensitivity response to o-benzyl-p-chlorophenol in mice.

o-Benzyl-p-chlorophenol was evaluated for its potential as a sensitizing agent for allergic contact hypersensitivity in mice. Female B6C3F1 mice were sensitized with 1.0, 3.0, and 10.0% o-benzyl-p-chlorophenol and challenged with 20.0% o-benzyl-p-chlorophenol. Doses of o-benzyl-p-chlorophenol were selected from assays for primary irritancy. Mice received 20 microliters by direct dermal application, for 5 days, to sites prepared by shaving, dermabrading and, in some mice, with intra dermal injection of Freund's complete adjuvant. The rest period was 7 days. Measurement of the contact hypersensitivity response in mice was by radioisotopic assay two days after challenge and mouse ear swelling test one and two days after challenge. Mice demonstrated statistically significant dose-dependent contact hypersensitivity response to o-benzyl-p-chlorophenol with or without adjuvant pretreatment.