RESIDUAL ANTIMICROBIAL ACT1VITY ON HUMAN SKIN 417 :.• / .-- ...• .,:,.,-: :....,....,!. •"•-•.•:...., ,•.: • '•4':••••' ' •" '••-•••• •"• '•q•C :•" :? iY/•"'.'?,--'-•% • ........ •.•. . '•/....• • • .•,•, • ............ ,. •........•, !•- ..',• :• i' "•LT' ...... •.'• ." "ila ".,!iJ '. Figure 6. Position of plates on arm outlined with magic marker method, a small study was run using 6 male subjccts. Four discrete areas on the arms were treated with the following preparations. 1. Dial'• soap,* 8% aqueous solution + 2. Ivory© soap, 8% aqueous solution 3. Phisohex©8 diluted one-fifth with d•stilled water 4. HyperHaze©** diluted one-fifth with distilled water The Dial soap used in this experiment contained 0.75% hexachlorophene and 0.75% triclocarban. HyperpHaze and pHisohex were liquid antimicrobial skin cleaners containing 3% hexachlorophene. The experiments described in this paper were run before problems using hexachlorophene arose, and the composition of the test materials was what was current at that time. The re- sults obtained on the first day', that is ilnmediately after treatment, are shown in Table I. *Arnmm'-Dial, Inc., Chicago, Ill. 60680. +These dilutions are reported to ])e in-use conditions. $Procter & Gamble, Cincinnati, Ohio 45202. •Winthrop Laboratories Division, Sterling Drug, Inc., N.Y., N.Y. 10016. **Pharmaceutical Division, Colgate-Pahnolive Co., N.Y., N.Y. 10022.

418 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table I Counts Per Plate Obtained on Day One Test Solution S.W. a P.B. a J.S, • E.E." K.C? A.L." X Per cent Reduction Ivory soap 253 252 255 248 193 249 242 Dial soap 170 174 177 174 146 178 170 pItisohex 126 134 109 126 101 128 121 HyperpHaze 90 92 85 95 85 94 90 Control (average count from 6 plates) 255 5.1 33.3 52.5 64.7 qnit•als of the subjects involved in the tests. Table II Counts Per Plate Obtained on Day Two Test Solution S.W. P.R. J.S. E.E. K.C. A.L. Ivory soap - •13 211 211 209 190 212 Dial soap 199 195 191 203 187 195 pHisohex 166 168 161 171 150 161 HyperpHaze 133 141 141 139 139 142 Control (average count from 6 plates) 2O8 195 163 139 216 Per cent Reduction 3.7 9.7 24.5 35.5 Table III Counts Per Plate Obtained on Day Three Test Solution S.W. P.R. J.S. E.E. K.C. A.L. X Per cent Reduction Ivory soap 19 t 196 186 194 192 192 Dial Soap 188 194 190 186 190 192 pHisohex 192 197 197 1'89 192 186 HyperpHaze 162 156 153 150 146 158 Control (average count from 6 plates) 193 - 190 - 192 - 154 21 195 Table IV Results Obtained on Day One Number of Average Number Standard Test Material Observations of Bacteria/Plate Deviation Per cent Change vs. Control Ivory soap 16 267.1 16.35 q- 0.2 Dial soap 16 221.8 14.89 --16.8 ptIkohex 16 167.3 12.93 --37.2 HyperpHaze 16 111.6 10.56 --58.2 Control s 15 266.6 16.33 - 'The controls were not placed on the arms, but put directly into the incubator.