484 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Consumer Tests--Creams & Lotions Product Category Product Type Creams Lotions Night Cream 11 -- Cleanser 7 7 Moisturizer 5 32 Freshener/Toner -- 15 Foundation -- 5 Skin Lotion/Milky Lotion -- 9 Other 5 5 -- Total 28 73 shampoo/shower gel samples assayed, four samples (1.6%) were unacceptable. These product samples did not meet the criteria for acceptability of 10 cfu/g upon retest and absence of S. aureus, E. co/i, and Pseudomonas species. Lotion A (Table V) was consumer-tested for four weeks early in 1980. Bacteria were recovered from three out of 189 samples (1.6%). Microbiological testing in early 1980 was not performed by a standard pour plate method. The product was directly streaked onto plates of nutrient agar and MacConkey agar. At this time in the test program, recovered organisms were not identified according to species. For Lotion A, growth occurred from streaks on nutrient agar only and not on MacConkey, indicating the absence of gram-negative contaminants. Microbial recoveries from the used product persisted for four weeks after test completion. After daily (2 x ) use of Lotion B for three weeks, Enterobacter cloacae was recovered (•103 cfu/g) from one out of twelve samples (8.3%). Recoveries of the organism re- mained after retest. One sample out of twenty-six (3.8%) of Lotion C had recovery of 1.2 X 103 cfu/g gram-positive Bacillus species upon retest. Bacillus species are not considered pathogenic, but these high recoveries of microbes were not acceptable. Table III Consumer Tests--Other Products Product Category No. Cleansing Foams 3 Toothpastes 3 Lip Treatment 2 Masks 2 Roll-On Deodorant/AP 1 Concealing Sticks 1 Cheek Blush/Pdr. Foundation 5 Lipstick/Lip Gloss 4 Eyeshadows/Eyeliner 7 Shampoos/Shower Gels 9 Hair Conditioners 4 Water-Based Mascara 1 -- Total 42

MICROBIOLOGICAL INTEGRITY OF COSMETICS 485 Table IV Consumer Use-Testing History Number of Samples Total Product Category Products Acceptable Unacceptable % Failures Creams 28 1121 0 0.00 Lotions 73 2177 5 • 0.22 Mascaras 1 79 0 0.00 Shampoos/Shower Gels 9 250 42 1.60 Hair Conditioners 4 140 0 0.00 Eyeshadows/Eyeliner 7 123 0 0.00 Lipsticks & Other Makeup 12 200 0 0.00 Miscellaneous 9 232 0 0.00 These unacceptable samples represent three products, or five out of a total of 232 samples. See Table V. These four samples are representative of one product panel of 23 consumers. Shower Gel D was used by a panel of 19 once or twice daily for three weeks. Four of the samples were unacceptable with high recoveries of 103 cfu/g upon retest. The contam- inant organisms included Citrobacter freundii, Serratia marcescens, and Serratia liquefaciens. Each of the four products which were unacceptable were reassessed. All three lotions had previously passed our in vitro challenge criteria. Lotions A and C were reformulated with preservative system changes. Imidazolidinyl urea was added to methyl paraben in Lotion A Lotion C was changed from a methyl paraben, benzoic acid system to methyl paraben with imidazolidinyl urea. The consumer-use panel was repeated for Lotion B in order to assess the statistical significance of the recovery of E. c/oacae. The panel size was increased to 34 people and the duration of the test increased to six weeks. After con- tinual daily use with increased panel size, all samples met the criteria for acceptability with no recoveries of microbes from the used product upon initial testing. The results of the first panel for Lotion B could not be reproduced therefore, this formula was consid- ered acceptable. The in vitro challenge testing of Shower Gel D resulted in low level recoveries (200 cfu/g) of two challenge organisms on week 3, one week after rechallenge. Replates were 10 cfu/g. Results indicate a product that is marginally preserved. The consumer-use testing results validated the formula as marginal. A change in the preservative system Table V Consumer Use-Testing Product Failures Samples Samples Product Category Tested Failed Preservative System A Lotion 189 3 B Lotion 12 1 C Lotion 27 1 D Shower Gel 19 4 Methyl paraben Methyl paraben, diazolidinyl urea Methyl paraben, benzoic acid Benzoic acid, phenoxyethanol