298 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS products regardless of the ambient weather conditions. The studies reported here were conducted in the New York-New Jersey area. MATERIALS AND METHODS Fourteen commercially available personal washing bars (designated bars A-N) were tested using the flex wash test. Compositional ingredients of these bars as obtained from the label are provided in Table I. Bar A was included as a reference since studies re- ported by others (2) demonstrated the mildness of this bar. The subjects were male and female volunteers between 20 and 55 years old. All subjects were in general good health with no history of dermatologic conditions. Informed con- sent was obtained prior to the initiation of the test. The antecubital fossae (flex area) of the arms were free of cuts and abrasions, with no irritation present at the onset of the study. Twelve to twenty subjects were randomly selected from a group of 200 for each direct comparison of two bars. The test group was then divided into two subgroups, which were balanced for hand dominance. Group I used product 1 on the left arm and product 2 on the right, while group II used the same two products but on opposite arms. All wash treatments were conducted by the subject under supervision in the laboratory. The sponge (JAECE Identi-Plugs, size D foam test tube plug) and the cleansing bar were moistened with tap water (approximately 100 ppm total hardness, maintained at 92 ø ___ 4øF) immediately before use. The sponge was stroked over one of the test bars ten times by the study monitor and placed in the subject's right hand. The left flex area was moistened with tap water and gently washed for 60 seconds. The washing proce- dure was an elliptical motion with 120 strokes per minute. The flex area was then Table I Composition of Commercial Personal Washing Bars Bar code Predominant ingredients E F G H I J K L M N sodium cocoyl isethionate, stearic acid, sodium tallowate, water, sodium isethionate, co- conut acid, sodium stearate sodium tallowate, potassium soap, water triethanolamine soap, sodium tallowate, glycerin sodium talowate, sodium cocoate, water, coconut acid, sodium polyacrylate, glycerin, cocoa butter sodium cocoate, sodium tallowate, water, glycerin, coconut acid sodium tallowate, sodium cocoate, glycerin, water, coconut acid sodium tallowate, sodium cocoate, water, PEG-6 methyl ether, triclocarban, glycerin dextrin, sodium laurylsulfoacetate, water, boric acid, urea, sorbitol, mineral oil, PEG-14M sodium tallowate, sodium cocoate, water, petrolatum, glycerin sodium tallowate, sodium cocoate, water, mineral oil, PEG-75, glycerin, lanolin oil sodium tallowate, sodium cocoate, water, vegetable oil sodium tallowate, sodium cocoate, water, sodium cocoglyceryl ether sulfonate, glycerin, coconut acid sodium tallowate, sodium cocoate, sodium cocoglyceryl ether sulfonate, glycerin, coconut or palm kernal acid, triclocarbon, polyquaternium-7 sodium tallowate, sodium cocoyl isethionate, water, sodium cocoate, stearic acid, triclosan

METHOD FOR SKIN IRRITATION 299 rinsed for approximately 10 seconds under running tap water until all lather was re- moved and then patted dry with a soft disposable towel. The procedure was repeated on the right arm using the left hand with the other product being tested. The test sites were treated three times daily with 1.5 hours between washings for five consecutive days. The test sites were evaluated by a trained examiner for irritation immediately prior to each wash and four hours after the third daily wash, for a total of 20 evaluations. Sites were graded using a seven-point scoring system (0-3). Dryness is not scored in this method as flakes are removed by the application procedure. Grade Description 0 Normal, no erytherna + Barely perceptible erytherna 1 Mild erythema, no edema 1 + Mild to moderate erythema, with/without edema 2 Moderate confluent erythema, with/without edema 2 + Moderate to deep erytherna, edema 3 Deep erythema, edema, vesiculation Each site was treated in the prescribed method for a maximum of fifteen washes or until a moderate confluent erythernic response (Grade 2) was elicited. When a grade of 2 or greater (Figure la) was attained, treatment of the site was discontinued. Continuing treatment beyond this point quickly results in a severe response and discomfort to the subject. The remaining flex area was washed until Grade 2 erythema was attained or fifteen treatments completed. Subjects were restricted from applying any rnoisturizing products to their arms. This included the use of body lotions, sunscreens, and bath oils. Additionally, subjects were instructed not to wash the test sites with soap during bathing. Sunbathing was prohib- ited during the test week. STATISTICAL ANALYSIS The data was analyzed by four methods. When an endpoint was reached, that score was carried through for all remaining evaluations. Mean total irritation score and standard deviation were calculated for each bar tested. This "mean erythema score" was used for general intercomparisons between tests and to provide a graphic picture of a bar's per- formance during the test week. For all statistical analyses, when a subject's first site reached an endpoint score, the scores for both sites were carried through for all remaining evaluations. However, treat- ment of the remaining site was continued. The following statistical methods were used: 1. A sign test utilizing the binomial equation was used to evaluate data for only those subjects who reached an endpoint. This method determined which product treat- ment resulted in achieving this endpoint first for erythema dryness was not evalu- ated. Subjects who were able to complete all wash treatments on both arms were considered a tie. 2. The Wilcoxon matched pairs test was used to compare erythema scores at the time of first site termination regardless of the number of treatments. The Wilcoxon test was also used to compare scores at each observation point.