SUBJECTIVE IRRITATION BY SOAPS 157 Table I Facial Irritation Study 1: All-Family Bars Accumulated mean sum -+ S.D. Bar A Bar B p-Value Erythema 4.47 + 5.28 20.00 + 16.57 Dryness 7.0 + 4,86 8.35 + 5.21 Tightness 7,18 -+ 4.65 7.53 -+ 5.24 Itching 1.76 -+ 3.34 1.47 -+ 2.85 Burning/stinging 3.24 -+ 3.33 3.82 -+ 4.13 0.002 0. 190 O.54O 0.370 O.64O Pearson correlation coefficients,' Bar B Dryness Tightness Itching Burning/ s?inging Dryness Tightness Itching Burning/stinging • 0.19 0.07 -0.21 0.01 0.88 0.002 0.89 '• 0.19 0.54 0.53 0.05 0.68 0.65 0.17 0.36 0.54 0.47 0.70 O.66 0.32 Erythema Dryness Tightness Itching Bar A Erythema Dryness Tightness Itching responses. There was no correlation indicated among the clinically scored erythema or subjective irritation attributes for Bar C in this study. The Pearson coefficients describing the relationship among the attributes for treatment with Bar D only, however, indicated some degree of positive correlation between all attributes except between erythema and both tightness and itching. Erythema was slightly correlated to both dryness and burning. Dryness moderately correlated to all other attributes, and tightness was highly correlated to both itching and burning. In the third study (Table III), comparing two synthetic complexion bars, there was no significant difference in the induced clinical erythema or in the subjective irritation attributes of dryness, tightness, itching, or burning/stinging between the two bars. For Bar E as well as Bar F, there was a moderate-to-strong positive correlation among all of the subjective irritation attributes, but no significant relationship between these and erythema. Washing with the synthetic detergent bar resulted in significantly less induced ery- thema than washing with an all-family bar in the fourth study (Table IV). No signifi- cant difference was perceived between the bars in terms of any of the subjective irrita- tion attributes. There was no significant correlation noted among any of the attributes for either bar. DISCUSSION Little work to evaluate the phenomenon of subjective irritation has been reported (2).

158' JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Facial Irritation Study 2: Complexion Bars Accumulated mean sum -+ S.D. Bar C Bar D p-Value Erythema 5.07 - 4.43 12.13 -+ 8.35 Dryness 1.67 - 1.88 3.20 - 2.96 Tightness 2.33 -+ 1.84 4.20 _ 3.45 Itching 0.93 - 1.28 3.40 - 3.79 Burning/stinging 1.40 - 1.60 4.33 - 1.08 0.023 O.O25 0.037 0.026 0.008 Pearson correlation coefficients.' Bar D Dryness Tightness Itching Burning/ stinging -0.17 -0.13 0.21 0.25 Dryness Tightness Itching Burning/stinging 0.67 0.60 0.48 0.70 0.79 0.80 0.72 0.63 •"••. 0.86 0.86 0.26 0.40 • -. 0.85 0.12 -0.02 -0.27 • Erythema Dryness Tightness Itching Bar C Erythema Dryness Tightness Itching Products evoking the feelings of itching, dryness, tightness, and/or burning/stinging in consumers, however, may be unacceptable and may fail in the marketplace. This paper describes the development of a method to investigate the subjective irrita- tion attributes of stinging as well as itching, tightness, and dryness induced by soap materials. A facial washing regimen, similar to that described by Frosch (7), was fol- lowed. Subjects were not pre-screened, but selected at random to provide a representa- tive consumer population. Ten percent aqueous solutions of soap materials were uti- lized, as this is the approximate concentration of soap used under normal use conditions (7). By including a skinfeel questionnaire during an exaggerated-use washing proce- dure, both clinical and subjective irritancy were evaluated. To develop the skinfeel questionnaire, subjects participating in various clinical studies were interviewed. The types of feel perceived on subjects' faces, the words used to describe this feel, and what those words meant to the subjects were determined. The seven-point category scale for each of the four subjective irritation attributes proved to be thorough and simple to use. A space was allotted for "other" discomfort, which allowed the subjects freedom to describe their perceptions in their own terms. A review of the data indicates that between pairs of soap bars, there is no strict relation- ship between induced erythema and subjective irritation. That is, if a significant differ- ence in erythema is determined between the test materials, there may (study #2) or may not (studies # 1 and #4) be a difference between the bars in self-perceived irritancy. In study #3, no significant difference was determined between the bars for either ery-