118 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Primary Irritation of Halogenated Compounds in Acetone Com- Species • Concentration (%)• pound 3.00 1.00 0.50 0.25 0.10 0.05 0.01 HCP DCP TCSA TBS BithionoI Fentichlor TCC TFC GP 10/10(1•) 10/10(1.6) 10/10(1.4) 15/20(1.0) 6/20(1.0) 0/20 0/10 R 5/5(1.8) 8/10(1.6) 8/10(1.9) 6/10(1.0) 3/10(1.3) 1/10(2.0) 0/10 GP 0/lO 0/10 0/10 R O/5 O/5 O/5 GP 10/10(1.0) B/10(1.0) 4/10(1.0) 0/10 0/10 R 5/5(1.0) 3/5(1.0) 2/5(1.0) 0/5 0/5 GP 0/10 0/10 0/10 R O/5 O/5 O/5 GP 0/10 0/10 0/10 R O/5 O/5 O/5 GP 0/10 0/10 0/10 R O/5 O/5 O/5 GP 0/10 0/10 0/10 R 0/5 0/5 0/5 GP 0/10 0/10 0/10 R O/5 O/5 O/5 •GP, guinea pig R, rabbit. *igures in parentheses indicate intensity of reaction. Figure 2. Primary irritation to HCP dissolved in acetone (marked erythematous reactions were shown with 0.5% an 1.0% HCP, and a slight erythema was shown with 0.25% HCP in the open patch test on guinea pigs)

SKIN SAFETY OF HEXACHLOROPHENE 119 applied with 0.1% or higher o[ HCP in acetone and in rabbits applied with 0.05% or higher concentration of HCP. A positive reaction expressed by a score of 1-2 was noticed in all the gu'nea pigs applied with 0.5% or higher concentration of HCP and in all the rabbits applied with 3% HCP. A positive reaction expressed by a score of 1-2 was recognized both in guinea pigs and rabbits applied with 0.5% or higher concentration of TCSA. Furthermore, when applied with 3% of TCSA, all the guinea pigs and rabb'•ts presented such irritation as expressed by a score of 1-2. On the other hand, no primary irritation was observed at all in any animal applied with 3% of any of the other six halogenated compounds. Figure 2 shows the primary irritation to HCP dissolved in acetone. The effects of vehicles upon the primary irritation of HCP in animals are shown in Tables III and IV. The skin irritation reaction was observed in guinea pigs applied with 5% and higher concentrations in polyethylene glycol 400, 0.5% and higher concentrations in olive oil, petrolatum, and propylene glycol, and 0.1% and higher concentrations in acetone. The results were the same in closed patch as in open patch tests. In the case of olive oil, however, the minimum concentration that produced irritation was 0.5% in the open and 1% in the closed patch tests. The concentrations of HCP which produced irritation in all the experimen- tal guinea pigs were 10% in polyethylene glycol 400, 3% in olive oil, 3% in petrolatum, and 1% in propylene glycol, regardless of the kind of patch test used. In the case of acetone, this concentration was 0.25% by the open or closed patch test. Skin irritation reaction was noticed in some of the rabbits tested with 5% in polyethylene glycol 400 vehicle (open patch test), 1% in olive oil, 0.5% in petrolatum, 0.5% (open patch test) and 0.25% (closed patch test) in propylene glycol, and 0.1% in acetone. The concentrations of HCP Vehicle Appli- cation Table III Primary Irritation of HCP in Various Vehicles (Guinea Pig) Concentration (%)• 10.00 5.00 3.00 1.00 0.50 0,25 0.10 0.05 Polyethylene glycol 400 Olive oil Petrolatum Propylene glycol Acetone Open 5/5(1.2) 2/10(1.0) 0/10 Closed 5/5(1.4) 3/10(1,0) 0/10 Open Closed Open Closed Open Closed Open Closed 10/10(2.0) 3/10(1,3) 1/10(1.0) 0/10 10/10(2.0) 2/10(1.0) 0/10 10/10(1.6) 6/10(1.1) 3/10(1.0) 0/10 10/10(1.6) 4/10(1,2) 1/10(1.0) 0/10 10/10(2.0) 10/10(1,6) 0/10 10/10(1.8) 8110(1.5) 0/10 7/7(1.8) 5/5(1.6) 5/5(1.4) 1/5(1.0) 0/5 5/5(1.8) 5/5(1.4) 315(1.3) 1/5(1.0) 0/5 •Figures in parentheses indicate intensity of reaction.