de Souza, João Carlos [UNESP]da Silva, Bianca Ferreira [UNESP]Morales, Daniel AlexandreUmbuzeiro, Gisela de AragãoZanoni, Maria Valnice Boldrin [UNESP]2020-12-122020-12-122020-04-05Journal of Hazardous Materials, v. 387.1873-33360304-3894http://hdl.handle.net/11449/200017This work reports the study of oxidation reaction of p-aminophenol (PAP) in ammoniacal medium in dissolved atmospheric oxygen and hydrogen peroxide, simulating the process of hair dyeing with permanent dyes. The products formed, which included semi-quinoneimine radical, quinoneimine, dimers, trimers and tetramers, were identified by mass spectrometry, infrared spectroscopy, UV–vis spectrophotometry, and nuclear magnetic resonance of hydrogen. The process was found to involve an autoxidation mechanism. The mutagenicity of the products was carried out by Salmonella Typhimurium YG1041 assay, and the results indicated no mutagenic properties. The presence of PAP and its oxidative products in samples of wastewater collected from hairdressing salon effluent (WW), raw river water (RRW), and water inlet and outlet of drinking water treatment plant (DWTP) was analyzed by HPLC-DAD. PAP was detected in the collected samples of WW, water samples from DWTP (before and after treatment), at concentrations of 2.1 ± 0.5 mg L−1, 1.9 ± 0.3 × 10-3 mg L−1 and 1.3 ± 0.2 × 10-3 mg L−1, respectively. The reaction products, including dimers, trimers and tetramers were identified only in the WW sample; this shows that both the precursor in the sample and its derivatives were released into the wastewater.engHair dye precursorsHair salon effluentsMutagenicity evaluationP-aminophenol oxidationPermanent hair dyesArtigo10.1016/j.jhazmat.2019.1220002-s2.0-85078691786