TOXIC AND ALLERGIC COMPLICATIONS OF HAIR DYES 117 where synthetic dyes were not used there were no cases of dermatitis or as thm a. Six cases of dermatitis occurring in various small fur dyeing establish- ments and supposedly due to fur dyes were studied. All six were patch tested with a 2 per cent solution of para for 48 hours. Four gave positive reactions and two negative reactions. Less than one per cent of workers employed were found to be suffering from dermatitis due to the. dyes. Combined statistics of the Labor Commission of New York and Ohio showed that in 1934, out of about sixteen hundred cases of occupational der- matiris reported to the Commission, 29 were attributed to the handling of dyed furs. These cases occurred among fur salesmen, fur cleaners, fur garment makers, and fur ironers. For mordant dyes to cause dermati- tis they must be so poorly applied to the fur that they readily come off or dissolve in the skin secretions of a sensitive wearer or handler. Such condi- tions are present only in poorly dyed and insufficiently washed and dyed furs, called "dirty furs" in the trade. Moreover, sensitivity to these substances must be present. The skin may be sensitive to any of the mordant dyes, but the chrome mordant and synthetic oxidation dyes, based on paraphenylenediamine, para-aminophenol and orthoaminophenol have been the chief causes of der- matiris. Rajka (25) studied 23 subjects sensitive to chemically related compounds of the so-called para group which includes various dyes used in coloring both foods and fabrics and numerous drugs, among them local anesthetics and sulfonamides and found that in the individual case the compounds included in the patient's allergic spectrum could not be predicted. Re- actions that would be expected on the basis of chemical structure did not necessarily follow. Thus, in patch test reactions to metol and hydro- quinone they were closely related as were relations to p-aminophenol and dimethylparaphenylenedia. mine in contrast to the results that chemical relationship would suggest. It seems that in certain instances a chemical allergen produces reactions on the basis of heptane linkage to protein, but in others it does not occur, the linkage being qualitatively and quanti- tatively different. In a woman who had become sensitized to various substances of the para group the injection of azo dyes used to color food was repeatedly followed by the occurrence of a papular eruption on the neck. Since sensitization to one drug in the para group entails a whole train of allergic reactions to chemically related substances patients with an allergic reaction to any of the sulfonamides, p-aminosalicylic acid, p-amino- benzoic acid, procaine and other drugs of para (para-amino) structure should be given another drug of related chemical structure only after

118 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS patch testing or should be given a drug with a similar reaction but a dif- ferent chemical structure (25). Paratoluenediamine, para-aminophenol, metol (paramethylaminophenol sulfate), and rodinol (pa-ra•aminopheva314vydrochloride) can be used instead of the para dyes. They are less toxic but not as effective as the latter. Amidol (2,4-di-aminophenol hydrochloride) can be used as a one solution dye. When used for fur dyeing para dyes will impart different shades from yellow to black depending on the type of dye and mordant used. Cases of dermatitis due to fur dyes are comparable to those encountered in dye- ing hair. The question of the toxicity of the coal tar derivative dyes, especially para and allied compounds, has become a serious problem because of the home hair dyeing kits. It is estimated that there are over fifty-five million applications of para dyes per year in this country alone. The hair dyes now being sold to the public for home use are put out as the so-called two-bottle package. One of the bottles contains a'solution of para, ammonia, and other ingredients, depending on the tint which is eventually to be produced, and the other bottle contains the oxidizing agent which is usually hydrogen peroxide. In carrying out the dyeing the con- tents of the two bottles are poured into a shallow dish and allowed to stand for about five minutes and then applied to the hair. It is usual in most well-prepared dye kits that the ammonia content of the final dyeing mixture should not exceed 11/2per cent, but surely should not be more than 2 per cent. The pH should not be higher than 10. Some of the preparations on the market tested by us had a higher pH. There must always be careful control by the laboratory to avoid an excess of free alkali. Pre-shampooing is not required with the home used hair dye. After the dye has been pre- pared as described above it is applied to the hair. It takes from one half to one hour for the desired color to appear. All of the excess dye, the am- monia and hydrogen peroxide are rinsed or shampooed off. Certain types of para dyes are now being sold as color shampoos. This is obviously quite dangerous to the eyes. It is the thinking of many workers in this field that the oxidation of the para should be allowed to go quickly because it is thought it becomes less of a potential irritant. The reasoning behind this will become evident when the question of themechanism of irritation of the para dyes is discussed. ß The Course of Paraphenylenediamine Oxidation The paraphenylenediamine is oxidized to quinonedi-imine and then a condensation takes place to what is known as Bandrowsky's base. Ac- cording to Cox (26), Bandrowsky's base is not the final compound obtained