512 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS The assessment procedure for an individual subject should be as brief as possible, avoiding complicated or long and tedious procedures Not more than two tests should be carried out daily with a given subject in the panel and the interval between two successive tests should not be less than 4 h. Each subject should be clearly told what characteristics of the test pro- duct should be considered. The way in which the testing procedure is carried out should be chosen individually by the subject. The investigator should ensure that subjects cannot influence each other's opinion. During each test, each subject should give an absolute appraisal about a given feature no comparison material whatever should be available at any time during the test. The subject's appraisal about the feature being tested should be ex- pressed by a rating: 0, 1, 2, 3 or 4 (4 = greatest effect, whether good or bad). To find out if there is any significant difference between two test series, the Wilcoxon's Q-test may be used, with a one-side overrun probability of 5%. For each consumer test, the ratings obtained were averaged and multi- plied by 2.5. The figure so obtained was called the factor for the aspect being investigated. (Minimum value 0, maximum value 10.) The factor on a 0-10 scale gave a figure suitable for ready interpretation of cough stimulation. After statistical analysis by the Q-test it became evident that a difference of 1 point between two factors was significant. All factors, therefore, were rounded to 0.5. Observations concerning the application of the test method to deodorant spray cough stimulation were: The cough stimulation test panel included 11 women and 21 men, aged between 18 and 45. No difference appeared bet•veen appraisal by men and by women, or between age groups. Two sprays were investigated each day, one in the morning and one in the afternoon. Hardly any difference appeared between morning and after- noon tests.

COUGH IRRITATION BY DEODORANT SPRAYS 513 Each subject was free to choose how to make the test. Two different methods were used: some subjects (19•o) tended to direct the aerosol spray towards the face from arm's length. The remaining sub- jects sprayed horizontally in front of the body and then remained immersed within the spray cloud. No overall difference in findings appeared between the two groups although, with the second method, the sprayed amounts of fluid were generally greater. Respiratory tract irritation was expressed as an integer, according to the following table: 0 no cough, 1 slight cough, 2 moderate cough, 3 strong cough, 4 very strong cough. After averaging, multiplication by 2.5 and rounding to 0.5, a value was obtained for each spray, giving a measure of the cough-stimulating poten- tial: the cough factor (CF). Cough-stimulating activity was assessed twice for each deodorant spray investigated. Reproducibility appeared to be good. The whole investigation lasted about 2 yr, with a total of 212 irritation tests. EXPERIMENTAL Preliminary studies Since at the beginning of this investigation nothing was known about the possible cough-stimulating potential of the various ingredients, first the cough-stimulating activity of a deodorant spray with a composition in common use was determined