TESTING DEODORANTS WITH CHLOROPHYLL AND DERIVATIVES 67 dorant efficiencies of the plain soap and the germicidal soap which are summarized in Charts IV and V. In actual use, soaps function as skin deodorants in a dual manner: (a) by cleansing soils from the cu- taneous surfaces and (b) by degerm- ing the skin. Although, on the basis of results of in-vitro tests, plain soaps fail to meet the specifications of germicidal agents (30), daily appli- cations of their aqueous solution to skin do effect substantial reductions in bacterial populations of skin, as shown in Chart IV. These degerm- ing effects of plain soaps are attrib- utable largely to their detergent properties and, only to a minor ex- tent, to their adverse actions on cu- taneous micro6rganisms. However, the cleansing capacity of the plain soap, as used in tub baths, which was the resultant of its detergent and degerming actions on skin, was unequal to the task of eradicating promptly existing odors and, even after four days of baths, of inhibiting the production of ob- jectionable odors during storage of perspiration. The most cogent evidence of the enhancement of the deodorant ca- pacities of soap resulting from incor- poration of a germicidal agent in the formula may be obtained by com- parisons of the numbers of baths with either soap requisite for the es- tablishment of satisfactory protec- tion against the probability of putre- factlye reactions on skin giving rise to detectable malodorous end prod- ucts. As determined by the meth- ods utilized in the series of experi- ments of Charts IV and V, this re- suit is indicated by the fact that samples of perspiration during stor- age do not develop odors having in- tensities exceeding pO values = 2, which are equivalent to air-dilutions of•, (31). In the experiments with the plain soap, five subjects showed thii re- sult after eight consecutive daily baths four more subjects exhibited the same result at the end of a bath- ing period of ten days on the elev- enth day, three additional subjects acquired satisfactory protection against the d•velopment of perspir- atory odors. Three subjects failed to achieve this degree of inhibition of odor-producing reactions in sam- ples of their perspiration. On the other hand, in the experi- ments with the germicidal soaps, the number of subjects exhibiting satis- factory protection against the de- velopment of perspiratory odors during the consecutive days of bathing were: (1) on the second day, five subjects (2) on the third day, a total of 10 subjects, and (3) on the fourth day, a total of 15 subjects. No subject failed to acquire satis- factory protection against the proba- bility of production of offensive per- spiratory odors during the first four days of the bathing period. Satisfactory protection against the development of offensive perspir- atory odors, as defined above, rather than complete deodorization of per- spiration has been adopted as the ultimate esthetic objective of skin cleansers in view of the fact that even a complete removal of soil from

68 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS the skin coincident with the maxi- mum degerming of the skin's sur- face would not assure the excretion of a non-odorous sweat in response to thermal stimulation during tests undertaken four hours after contact of the cleanser with the skin. Un- der the conditions of the sweating tests, odorous end products of metab- olism of which the rate has been stepped up by increases in both the internal and environmental temper- atures of the body may be excreted by way of the coil glands (32) and, thereby, contribute to intensities of odors of perspiration.' These odors attributable to metabolites may be differentiated from perspiratory odors by two major criteria: (a) they are not unpleasant and usually faint intensities of these odors, when measurable, vary inversely with the volumes of perspiration collected and (b) intensities of odors arising from metabolites eliminated in sweat do not increase during periods of storage of perspiration under condi- tions which are propitious for the growth and multiplication of cuta- neous bacteria. Determinations of odors of samples of perspiration im- mediately after collection and again at the ends of periods of storage and directing particular attention to the increment in intensities of the odors during storage afford more reliable indices of greater reproducibilities of the detergent and degerming actions of skin cleansers in respect to their capacities to protect against devel- opments of objectionable perspira- tory odor than do the odor values of fresh samples of perspiration. Although observations of the bio- logical reactions of inocula of pure cultures of micro6rganisms into aliquots of sterile perspiration have shown that the production of malo- dorous metabolites is not a common characteristic of all species of cu- taneous bacteria which have been isolated and identified to date nev- ertheless studies of about 2000 sam- ples over a period of approximately two decades have demonstrated uniformly good correlations between intensities of odors produced and rates of growth and multiplication. Conversely, restrictions of growth and reproduction of the cutaneous organisms, by antibacterial agents, retard rates of production of offen- sive odors. Finally, removals of all viable micro/Srganisms from perspi- ration inhibit completely the develop- ment of obnoxious odors no matter what the soil content of the perspira- tion may be (33). All of these findings lead to the inescapable con- clusion that control of the bacterial populations on the surfaces of skin is the "sine qua non" of the control of perspiratory odors. In his pub- lication entitled "Cosmetic Aspects of Perspiration," Klarmann (34) has presented a comprehensive and instructive review of the chemical and biological reactions resulting in the production of objectionable odors on skin. Inasmuch as the two soaps were utilized for cleansing the entire cu- taneous areas of the subjects' bodies (except those of their heads and necks), it was imperative to sample both perspiration and cutaneous