EVALUATION OF ANTIBACTERIAL SOAP BARS 351 Three different consumer usage skin degerming evaluation tests will be described. The first was a test to determine effectiveness of Anti- bacterial Bar A relative to ordinary nonsanitizer soap. The study was run in the month of February in a northern city. Two groups of ap- proximately 150 subjects each were sampled for the bacterial level on their hands and then were assigned on a random basis either the anti- bacterial soap or its control (without an antibacterial) to be used ex- clusively (ad lib.) in place of the customary bar soap product. After two weeks, the bacterial flora on the hands was redetermined. The data in Table IV show that the antibacterial soap users had a bacterial TABLE IV Skin Degerming: Effectiveness in a Temperate Environment under •ld Libitum Usage Conditions Handwashing--Second t3asin Mean Bacterial Count Per Liter Initial Two Week Test Product Sampling Sampling Antibacterial soap A s 4,920,000 1,960,000 Control soap b 5,210,000 3,310,000 Antibacterial additive: 2% mixture of BSA, TFC, and TCC. No antibacterial additive. population on their hands lower than that of a comparable group using the control bar. An analysis of variance showed that this difference was significant at P 0.05. The second test was performed to determine the skin degerming efficacy of Antibacterial Bar A under hot, humid weather conditions. This study was conducted in a southern city during the month of July. Two groups of housewives were sampled for bacterial levels on the skin initially one group was then assigned the antibacterial soap and the other the control soap without sanitizer additives. The test was con- ducted on a double-blind basis neither the subjects nor the bacteriolo- gists knew who was assigned the antibacterial product until the test was completed. The subjects were sampled for the levels of bacteria on the skin after two and four weeks of assigned product usage. The results of the handwashing tests (Table V) show again that there was a reduction in the bacterial flora on the skin of the subjects using the anti- bacterial soap. The difference between the bars was statistically sig- nificant (P 0.05).

352 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS The results of this test, in general, corroborated the previous clinical test findings regarding the skin degerming efficacy of the antibacterial soap under ad lib. conditions. This test also showed that the anti- bacterial bar soap reduced the total skin bacterial level found on the hands as effectively in a sub-tropical climate as in a northern or tem- perate climate. A third test was conducted to determine the capability of the hand- washing test to detect differences in the relative skin degerming effective- ness of two antibacterial bar soaps containing different antibacterial systems. Degerming efficacy differences had already been detected under the above described laboratory handwashing conditions. The TABLE V Skin Degerming: Effectiveness in a Sub-tropical Environment under Ad Libitum Usage Conditions Handwashing--Second Basin Two Weeks Four Weeks Test Product Usage Usage Antibacterial soap A n 665,000 441,000 Control soap b 1,381,000 1,126,000 Antibacterial additive: 2% mixture of BSA, TFC, and TCC. No antibacterial additive. TABLE VI Skin Degerming Effectiveness of Two Different Antibacterial Systems Handwashing--Second Basin--Ad Libitum Usage Mean Bacterial Count Per Liter Two Weeks Four Weeks Test Product Usage Usage Antibacterial bar soap A s Antibacterial bar soap B • Control soap c 649,000 657,000 1,513,000 1,403,000 3,715,000 3,495,000 Antibacterial additive: 2% mixture of BSA, TFC, and TCC. Antibacterial additive: 0.75% TCC + 0.75% G-11. No antibacterial additive. test was conducted in a northern summer environment. Antibacterial Bar Soap A containing the 2% mixture of BSA, TFC, and TCC Anti- bacterial Bar Soap B containing 0.75% TCC plus 0.75% G-11 and a control bar with no antibacterials were randomly distributed to approxi- mately 500 housewives. Distribution was such as to obtain three equal-sized groups using each test bar. The test was conducted as a