COLD WAVE LOTIONS CUTANEOUS AND SYSTEMIC EFFECTS 231 posite stand. Those articles which condemn the cold wave process rely primarily upon the published ar- ticles of Howell (4) and Cotter, and in so commenting, add to the list of adverse literature on the subject, without actually contribut- ing new data. Mention is infre- quently made of the method em- ployed or of the chemical composi- tion or concentration of the material tested, or whether a solution of am- monium thioglycolate or a commer- cial wave lotion had been used. This report partially reported elsewhere (5) concerns the effects of certain cold wave lotions on the health of 1200 persons who volunteered for tests of these prod- ucts. In order that the results might have practical value, the material employed in these tests was a commercial home cold wave preparation in wide popular use, rather than an empirical solution of a salt of thioglycolic acid. In addition, many other impor- tant considerations of a chemical nature dictated the use of an actual cold wave preparation. Among the constituents of cold wave lotions are ammonium hydroxide, thio- glycolic acid, and a wetting agent. The ammonia, which is a gas at room temperature, is dissolved in water to form ammonium hydroxide, which has a high vapor pressure. From its water solution ammonia volatilizes rapidly, especially under conditions of good exposure af- forded during the cold wave proc- ess. The thioglycolate, likewise, is very susceptible to atmospheric oxidation, being oxidized to a rather inert substance, diammonium di- thioglycolate, under conditions of usage exposure. For these reasons, the waving lo- tion which comes in contact with the scalp is very rapidly converted into a relatively inactive material. The wetting agent which is present, while causing more intimate contact with the skin, also causes the solu- tion to spread over the skin surface in a very thin film. This increases the exposure of the lotion to the air, enhancing volatilization of the am- monia and oxidation of the thio- glycolate. On the other hand, the cold wave lotion in contact with the hair, under actual hair waving conditions, does not change so rap- idly because each tress is coiled, de- laying the decomposition of the cold wave solutions, ex:ept on the outer- most surface. Because the chemical reactivity of cold wave solutions is affected by the concentration of am- monia and thioglycolate, by the pH, and by the type and amount of wetting agent used, the results ob- tained in our work apply only to the waving lotion we used. A seri•s of studies was performed on normal subjects and on subjects with various skin diseases on persons with no known contact with cold wave solutions and on many in intimate and prolonged contact--- in a successful attempt to delineate fully and critically the part, played by cold wave lotions on the health of that part of the population most likely to come in contact with these materials. Recent experience in

232 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS evaluating the sensitizing effects of materials by relying on the reac- tions of two hundred subjects to patch tests dictates caution in formulating conclusions based upon such a number of patch tests alone. More recent methods, some of which have been adopted in this study, yield results affording greater precision in their interpretation. For example, (1) the routine use of adequate numbers of paired patch tests (equivalents to four or the usual single patch tests) (2) the retesting within two to four weeks of each individual in order to deter- mine any development of sensitiza- tion and (3) most important of all, an adequate experience over a prolonged period of time under conditions of actual use, are the innovations which have been adopted. These have strengthened the validity of conclusions based upon the relation between actual us- age and the incidence of positive skin patch tests, on the one hand, and the occurrence of dermatitis from contact with cold wave lotions, on the other. Whereas the adequacy of patch testing when used alone as a measure of irritancy and al- lergenicity may be reasonably open to question, the authors believe that the experimental procedure in each case must be subjected to in- dividual considerations. In this connection, a recent publication (6) from our service at Bellevue Hos- pital may be cited. Patch test reactions to a mild fungicide were compared with the incidence of reactions occurring under actual usage conditions. It was found that patch tests gave reactions which were much more frequent and severe than the incidence of dermatitis when the material was in actual use. A number of subjects who were tested by standard patch test meth- ods responded to the chemical with moderate to severe reactions. These same subjects were subsequently subjected to the daily therapeutic use of the identical chemicals with- out eliciting any cutaneous reac- tions, even after prolonged use. A possible interpretation for these findings is that in actual use the composition of the reactive chemi- cals may have been altered by such factors as volatility, 5nstability and reactivity with the air, the skin and with any other materials. A substance should be rejected as an irritant or accepted as inert only when the results of patch tests are confirmed by actual use. In this investigation of cold hair waving lotions, over 1200 persons in varying degree of contact with such preparations were used as sub- jects. The first phase of these studies dealt with the primary irritancy of ammonium thioglycol- ate. It was shown to be of a low order, even when the concentration was triple that of the solution in common use. Paired patch tests using the solutions employed in the cold wave process were performed on several hundred subjects with various skin diseases. These tests showed that the cutaneous reac- tions from contact with or exposure to. these materials were of a neg-