Related Experiment Video
Updated: Sep 14, 2025

Synthesis of Plant Phenol-derived Polymeric Dyes for Direct or Mordant-based Hair Dyeing
Published on: December 1, 2016
Comprehensive Review of Hair Dyes: Physicochemical Aspects, Classification, Toxicity, Detection, and Treatment
João Carlos de Souza1,2, Elisa Raquel Anastácio Ferraz Avelino3, Guilherme Garcia Bessegato4
1Faculty of Philosophy, Sciences, and Letters at Ribeirão Preto (FFCLRP), Department of Chemistry, University of São Paulo (USP),Avenida Bandeirantes, 3900, Ribeirão Preto, São Paulo State 14040-901, Brazil.
Abstract:
Hair dyes have been a significant facet of human culture and identity, evolving from ancient natural pigments to complex synthetic formulations. This comprehensive review delves into the multifaceted dimensions of hair dyes, examining their physicochemical properties, classification, toxicity, detection, and treatment methods. The review explores the historical progression and contemporary advancements in hair dye technologies, highlighting the persistent challenges posed by their environmental and health impacts. It categorizes hair dyes into vegetable, mineral, and synthetic types, further subdividing synthetic dyes into temporary, semipermanent, and permanent categories based on their durability and application methods. This review also discusses the toxicological concerns associated with hair dyes, emphasizing the acute and chronic health risks posed by ingredients such as p-phenylenediamine (PPD) and its derivatives. Analytical methods for detecting and quantifying hair dyes in various matrices are evaluated, showcasing techniques such as chromatography and spectrophotometry. Furthermore, the review addresses the environmental implications of hair dye disposal, focusing on innovative treatment approaches, including advanced oxidation processes and bioremediation strategies. By synthesizing the last 20 years of the literature, this review provides a balanced perspective on the benefits and risks associated with hair dyes, offering insights into future research directions and sustainable practices to mitigate their adverse effects on human health and the environment.
Related Concept Videos
Toxic Reactions: Overview
Toxicity falls into two primary categories: local and systemic.
Local toxicity appears at the exposure site, such as protein denaturation caused by caustic substances.
In contrast, systemic toxicity requires the toxic agent's absorption and distribution,...
Effects of Chemicals: Overview
Effects of EDTA on End-Point Detection Methods
In the visual method, metal-ion indicators (metallochromic dyes), which have distinct colors in their free and complex forms, are added to the mixture to signal the titration's end point. They form stable complexes with metal ions, but these complexes are weaker than the corresponding metal–EDTA complexes. As a...
Changes in Skin Color: Clinical Perspectives
Albinism
Albinism is a genetic disorder that affects (completely or partially) the coloring of skin, hair, and eyes. The defect is primarily...
Drug Regulation
Mutagenicity and Carcinogenicity

