The absorption of p-toluenediamine through human skin in hair dyeing.
ABSTRACT After the hair of 5 persons had been dyed with a simple dye, prepared by oxidizing a mixture of 2.5 g of p-toluenediamine sulfate and 2.5 g resorcinol with hydrogen peroxide, an average of 3.7 mg N,N′-diacetyl-p-toluenediamine appeared in the urine. A similar amount of N,N′-diacetyl-p-toluenediamine, namely 4.5 mg, was found in the urine when 5.5 mg of p-toluenediamine was subcutaneously injected. From these data it is calculated that about 4.6 mg of p-toluenediamine was either absorbed during the hair dyeing or produced in vivo from a compound formed during the preparation of the hair dye and absorbed through the skin while the dye was applied to the hair and scalp.
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ABSTRACT: Although p-phenylenediamine (PPD) has been recognized as an extreme sensitizer for many years, the exact mechanism of sensitization has not been elucidated yet. Penetration and the ability to bind to proteins are the first two hurdles that an allergen has to overcome to be able to sensitize. This review is an overview of studies regarding PPD penetration through skin (analogues) and studies on the amino acids that are targeted by PPD. To complete this review, the auto-oxidation and N-acetylation steps involved in PPD metabolism are described. In summary, under normal hair dyeing exposure conditions, <1% of the applied PPD dose penetrates the skin. The majority (>80%) of PPD that penetrates will be converted into the detoxification products monoacetyl-PPD and diacetyl-PPD by the N-acetyltransferase enzymes. The small amount of PPD that does not become N-acetylated is susceptible to auto-oxidation reactions, yielding protein-reactive PPD derivatives. These derivatives may bind to specific amino acids, and some of the formed adducts might be the complexes responsible for sensitization. However, true in vivo evidence is lacking, and further research to unravel the definite mechanism of sensitization is needed.Contact Dermatitis 04/2013; 68(4):193-207. · 3.62 Impact Factor
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ABSTRACT: A population-based case-control study was conducted in Los Angeles, California, which involved 1,514 incident cases of bladder cancer and an equal number of age-, sex- and ethnicity-matched controls. Information on personal use of hair dyes was obtained from 897 cases and their matched controls. After adjustment for cigarette smoking, a major risk factor for bladder cancer, women who used permanent hair dyes at least once a month experienced a 2.1-fold risk of bladder cancer relative to non-users (p for trend = 0.04). Risk increased to 3.3 (95% CI = 1.3–8.4) among regular (at least monthly) users of 15 or more years. Occupational exposure to hair dyes was associated with an increased risk of bladder cancer in this study. Subjects who worked for 10 or more years as hairdressers or barbers experienced a 5-fold (95% CI = 1.3–19.2) increase in risk compared to individuals not exposed. © 2001 Wiley-Liss, Inc.International Journal of Cancer 12/2000; 91(4):575 - 579. · 6.20 Impact Factor
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ABSTRACT: A number of epidemiological studies have attempted to assess the potential increase in risk of cancer among occupational groups, e.g., hairdressers, beauticians, and others, and, by inference, to associate this risk with hair dye use. The results of such studies have only raised suspicions of an increased risk. Lack of adequate demographic and exposure information prevents the interpretation that increased risks are associated with any chemicals to which such people are occupationally exposed. In case-control studies of bladder or breast cancer either no increased risk was found with hair dye use or conflicting evidence was reported. Only one study has reported an increased risk of breast cancer associated with hair dye use in female patients who were at low risk for breast cancer for other reasons.Regulatory Toxicology and Pharmacology 12/1981; 1(3):388-400. · 2.13 Impact Factor