The test for primary irritation was conducted by applying, and lightly rubbing in, 1 drop (=0.05 al) each of a 25% and 2.5% solution (wt/vol) of the test material in FAD on the shaved intact shoulder skin of 10 male albino guinea pigs. To test for the sensitization potential, a .series of four sacral intradermal injections was given, one each week over a three-week period, which consisted of 0.1 ml of a 1% solution (wt/vol) of test material in dimethyl phthalate. Following a two-week rest period, the test animals were challenged for sensitization by applying, and lightly rubbing in, 1 drop (=0.05 al) each of a 25% and 2.5% solution (wt/vol) of test material in FAD on the shaved intact shoulder skin. A group of 10 previously unexposed guinea pigs received similar applications at the time of challenge to provide a direct comparison of the challenge reactions on skin of chilar age. After an additional two-week rest period, the animals were rechallenged following the same procedure for the challenge as a further check for sensitization.